Astronomy - Things in the Sky - 01
A View of Atoms from within the Cosmic Globe
By tobagojo

A Visual Travelogue
Just browse and enjoy the images, if you’re not into the words!

WORK IN PROGRESS (June 2012 - October 2017) - Authors note.
@ October 2017; Astronomy - Things in the Sky is still a work in progress from a slight West Indian perspective, from Trinidad, TT. It undoubtedly contains errors, together with a few speculations by the author which may be somewhat off the mark, but hopefully not overly so. However, all in all, striving from a slightly unusual viewpoint, the author attempts to be as accurate to today’s understanding of science as the author can presently glean.

The text still needs proper referencing, links and updates; in particular to cover the last couple of years of truly remarkable discoveries in astronomy and physics that have recently emerged to confound us. But, with a bit more time, some will hopefully eventually get entered here.

This has been posted now, as the author would like to share what’s here, to encourage the inquisitive, sooner rather than later. The sands of time keep falling relentlessly and 21st Century distractions are just as disruptive to effort.

My heartfelt thanks to all those whose work, in whatever form, is here displayed. Their deeds and works drive an ever hopeful adolescent technological civilisation forward. My apologies to any who may feel inconvenienced by contained errors or omissions; but will attempt to better this effort, as soon as able.

However, specific mention to the writings of the indomitable Richard Rhodes and his The Making of the Atomic Bomb © 1986; that has been used large, but is not the only of references used here. Rhodes skill of organisation remains a constant inspiration.

Thanks for your time and thanks for your visit. Your comments are welcome.
Till next. Chao.

tobagojo - San Fernando, Trinidad, TT.


This compilation is, with warmth and with no little degree of awe at times during its research, dedicated to three groups of individuals who have been inspirational to the making of this, the ‘Things in the Sky’.

Fondly to my children who, serendipitously, collectively have really acquired the acronym DNA; and for whom this is intended as a guide to Science.

To women in general who, in some places, are still undervalued as people, despite their most valid position to being in general, half of the population; and without whom, there would be none at all. In particular, to the women cited in this dialogue, many of whom were pioneers and leaders in their speciality; but more notably proved to have insights and abilities equal, and sometimes beyond, that of their peers, in a male dominated society. May they remain inspirational to many others.

To the creators of Science Fiction, the philosophers of the future, who meld art and science into that imaginative beyond, that is so inspiringly prescient with promise, yet at times also speckled with cautions of what could be; should we not take note while we still have time to think and act with humanity. - San Fernando, Trinidad, TT. 3rd June 2013.

The Solar System & The Planets

The Sun - Sol

10 - The Sun - Spectral classification as a G2V type star.
Data on The Sun: Mass = 1MSol = 1.989 x 1030 kg (332,000 times the mass of the earth); Equatorial radius: RSol = 696 x 103 km (432.47 x 103 mi); Mean density: 1,410 kg/m3; Surface gravity: 274 m/sec2; Escape velocity: 618 km/sec2; Surface temperature (effective): 5,780 K; Luminosity (Power output): LSol = 3.85 x 1026 Watts; Solar constant @ top of earths atmosphere [All wavelengths; see Black Body Radiator](Power per unit area before atmospheric losses) = S = 1,370 Watts/m2
Solar Dynamics Observatory (SDO) 19th August 2010
The Atmospheric Imaging Assembly of SDO; Filter: Extreme ultra-violet - NASA

  The cellular morphology of the turbulent surface of the sun. Flares or solar prominences are particularly visible at the outer edges (limb). The mottled structures are cells of gas rotating back into the outer surface of the sun.
Sun_02a_spots_Paul-Andrew_(Solent-News) 10 - The Sun and Sun Spots

Paul Andrew (Solent-News)
Thursday, 27th September 2012

  A ~582,000 km (361,638 mi) prominance of cool ejected gas spirals tangled in magnetic fields across the face of the sun.
10 - The Sun and Prominances

Paul Andrew (Solent-News)
Thursday, 27th September 2012

10 - Theoretical models of the Sun
Adapted from Astronomy Today

  (a) The sun has been found to oscillate, at very low frequencies, ringing like a bell. These vibrational modes of an oscillating sphere are used by scientists to infer some internal structures of the sun, by similar analyses to those used in seismic surveys, where p and s pressure waves are used to analyse the interior structure of planet Earth. The science is called Helioseismology when applied to the Sun. A helioseismic model of the Sun is shown above where differences in pressure are modelled in different colours to illustrate the behaviour of hot fluids (plasma) within a gravitationally bound sphere in hydrostatic equilibrium.

  (b) Taken from The Standard Model of the Sun (a G2V type star), currently understood internal and surface structures of the sun are displayed. In the high density volume of the core the p-p chain thermonuclear process (see later) generates the suns energy by transmuting hydrogen into helium. In the radiation zone, the energy passes through a mainly non-reactive volume of hydrogen plasma by electromagnetic wave transport, cascading down in frequency, the further from the core it travels; a process estimated to take in the order of 170,000 years before energy derived from the core arrives at the outer convective shell. At the convective zone, the state of ionization of the hydrogen becomes opaque to radiative transport, so instead, the heated plasma rises in convective cells to dissipate the internal energy to the shells above it. The photosphere is the region from which the electromagnetic radiation of the sun is now that which leaves the sun at the frequencies consistent with that of a black body radiator at a temperature of ~ 5,780 K, conveying to us the visual aspect of the surface and colour of the sun that we see; travelling from sun to earth in ~ 8 minutes. By this stage, it is estimated that the time taken for the core energy to arrive at the visible surface of the sun, has been to the order of 30 million years. Some 98% of the cores nuclear energy is expelled by this means; the other 2% invested in neutrinos, a fusion product, which at the speed of light, had long left mostly unimpeded through the outer solar shells, some 2.3 seconds after being created.
  The chromosphere, transition zone and corona, are considered parts of the solar atmosphere. The chromosphere, which falls off in temperature to ~ 4,500 K at its upper limits, is a mixture of ionised gasses which imprints on the solar spectrum traces of some 67 different elements in various states of ionization.

  (c) The transition zone demarks a voluminous shell within which the temperature rises to over 1,000,000 K by processes not completely understood at this time, but believed to be associated with magnetic phenomenon associated with this shell; where now the suns outer surface begins to evaporate into space forming the corona of ionized particles that leave the sun, spiralling around magnetic field lines that leave the sun.
sun_total-eclipse+coronal-features_01_450w sun_total-eclipse+coronal-features_02_450w
10 - Total Solar eclipse - The eclipse of the Sun by the Moon - The solar corona in visible light; with the just discernable face of the moon illuminated by earthshine.
Left: (Unknown source); Right: 2001 by F Espenak

  The corona, barely visible in the visible part of the spectrum, and only so during the total eclipse of the sun by the moon when the normally overwhelming glare of the photosphere is blocked out, where the imprint of gross solar magnetic field lines are starkly evident; through analyses in the high ultra-violet and X-ray part of the electromagnetic spectrum, spectra selective to structures at relativly high temperatures. Some parts of the corona are noted to have risen to a temperature between 18 to 20 Meg K.sun_Heliospheric-current-sheet_02_450w_200h
  The solar wind streaming off the corona, is called the heliosphere; which is defined as extending from approximately (20 solar radii) 0.1AU to around 50AU away from the sun, at which point it converts to a shock front with the inter-stellar medium (ISM), atoms and molecules of gasses and dust that is tenuously present in inter-stellar space. This is an area of high energy-particle density, recorded by the Voyager 1 probe in December 2004, called the heliopause; and consequently reconfirmed by Voyager 2; it lies at the outer edge of the Kuiper belt.
  The heliosphere of streaming particles in the suns magnetic field stretches out along the ecliptic to the heliopause. The rotating sun twists the extended field into an Archimedean spiral. Because of differences in polarities induced by the magnetic poles, there exists a current flow called the Heliospheric Current Sheet that is illustrated as a Parker spiral (as shown alongside).
Partial solar eclipse, San Fernando, Trinidad, TT, WI, pin-hole image_tobagojo@gmail.com_composit_20170821_DSCN4195_2
10 - Partial Solar Eclipse, 21st August 2017, viewed from San Fernando, Trinidad, West Indies - Imaged by pin-hole
Note: Pin-holes, just like single lenses, invert images.   By tobagojo

  With no protective goggles available, and with the tropical sun blazing contented and mightily overhead, couldn’t see a thing! A copy-book was placed on the ground in the bright sunlight, at around the time of maximum solar eclipse at San Fernando, Trinidad. TT. A thin sheet of cardboard (~Bristol-board card) with a pin-hole (made with a fine needle) was held over the copy-book, so that the inverted image of the sun appeared at an appropriate size (not much leeway there!) and in a convenient place on the copy-book; then a photograph was taken of the shadows on the copy-book.
  True North was estimated (don't have a compass, sorry!) and marked on the picture in green,. The image of the eclipse on the coppybook was enlarged; then placed to the right of the image with the green true North inverted (because pin-holes invert).
  The enlarged eclipse image was then rotated so that the green North matched with the pink North orientation of the expected eclipse as displayed by the computations for the location of San Fernando, Trinidad, by the remarkable 'Google interactive map by Xavier M Jubier'.
  Oh well, it's pretty close; my North must be a bit out! Must get a compass. But did capture and ‘see’ the eclipse, that was cool, wow!
Sunspots_Georgia State University, Dept of Geosciences, Climate Literacy Labs_20140520_Sunspots-24a151h_3
10 - Sunspots
Georgia State University, Department of Geosciences, Climate Literacy Labs; 20th May 2014

sun_30_Sunspots-and-Prominences_SDO_02Feb2013_Extreme-ultra-violet_NASA-AIA-HMI_Goddard-Space-Flight-Centre_450x338 sun_32_Sunspot-Cluster_SOHO-Sept2000_Extreme-ultra-violet_NASA-ESA_47895_450x338
10 - Sunspots and Prominences (left) + Sunspot Cluster (right)
(left) SDO 02 February 2013 Extreme ultra-violet - NASA, AIA, HMI, Goddard Space Flight Centre
(right) SOHO September 2000 Extreme ultra-violet - NASA, ESA

  Dark Earth sized spots (the larger) on the surface of the sun. The spots appear dark in visible light because they are slightly cooler than the surrounding regions (~ 4,500 K).
  Sunspots often travel in groups across the solar surface and can linger for days or even months. The spots are the birthplaces of solar events such as flares and coronal mass ejections.

SOHO - Solar & Heliospheric Observatory; ESA,^gallery^Spacecraft^large^SOHOopen_prev+soho_photo11_lum-NR+shp_990w_560h
10 - SOHO - Solar & Heliospheric Observatory satellite
Spacecraft illustration with solar panels deployed (left); Engineering spacecraft at Matra Marconi Space* facilities (right); ESA, NASA

  * Now EADS Astrium under overall management by ESA.

  SOHO Spacecraft visualisation and during build. The satellite weighs in at ~?2,032 kg? (2 tons) and spans 7.62 m (25 ft) across with its solar panels extended. SOHO was launched in December 1995 via the launch facility SAEF-2 of the Kennedy Space Centre, pad 36B, atop an Atlas Centaur AC-121 rocket; and became operational in March 1996.

  SOHO, the Solar & Heliospheric Observatory, is an international collaboration between ESA and NASA to study the Sun, with instruments to probe the solar core, its outer corona and the solar winds. Engineering was provided by over 200 international investigators. NASA is responsible for the launch systems and mission operations. Mission control is based at the Goddard Space Flight Centre, Maryland, USA.

10 - Sunspot and Granules
(Source - this image - unknown). [Root:] The Swedish 1-m Solar Telescope (SST) on the island of La Palma, Spain; Royal Swedish Academy of Sciences. Wavelength: 436.4 nm (Continuum); Target: AR 425 at ?=40.5°, µ=0.76; 04 Aug 2003; processing Mats Löfdahl; By Göran Scharmer and Kai Langhans, Institute for Solar Physics (ISP), Stockholm, Sweden.

  This high-resolution picture shows clearly that the Sun's face is a bubbling sea of separate cells of hot gas or plasma. These cells are known as granules, and are small convection cells. At the centre of the cell the plasma rises, then spreads out towards the edges cooling, to sink down again in a convective loop.
  The granules at the base of the ~500km (~310 mi) thick photosphere are about 1,000 km (620 mi) across on average; and last for about 10 minutes before dissipating to be replaced from underneath. It is thought that similar but larger cells reside below this upper layer, progressively getting larger the deeper they are into the convective zone; which is about 200,000 km (124,000 mi) deep.
  The diameter of the sun spot, can be anything up to around 10,000 to 15,000 km (6,200 to 9,300 mi) across. A display of accelerated ionized particles, tightly spiraling around fringe magnetic fields in dark tendrils, called spicules, occupy the lips of the spot. The dark part of the spot harbors an intense core of magnetic fields emerging out of the convective zone.
Swedish 1-m Solar Telescope, La Palma by Dan^gallery^images^photos^DCP_5089_turn_B_r-1.30_576w_678h 10 - The Swedish 1-m Solar Telescope (SST)
ISP, Stockholm, Sweden; by Dan Kiselman

  The Swedish 1-m Solar Telescope (SST), first light 2nd March 2002, is operated by the Institute for Solar Physics (ISP), Stockholm, Sweden. of the Royal Swedish Academy of Sciences and is located within the Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias on the island of La Palma, Spain.

  The largest optical solar telescope in Europe, SST uses a clear aperture front lens, just under 1 meter in diameter. It is a vacuum telescope, using its lens as a vacuum seal. It uses further 1kHz adaptive optics internally, the first solar telescope to do so; and has a second optic path for colour correction using a Schupmann corrector method. SST can resolve details as small as 70 km on the suns surface.

10 - Sun - Solar flare
SDO February 2011 Extreme ultra-violet - NASA

  Plasma loops in magnetic fields
Sun_38_2xSun-Spots_AR9169-Lg_AR9167-Sm_TRACE_Sep2000_ultraviolet-171Å-passband_bright-gas-emission-1MK_cooler-materials-dark-absorbing-structures-10kK_NASA_450h 10 - Sun - 2 x Sun Spots AR 9169 large (back), AR 9167 small (front)
TRACE September 2000 Ultra-violet 171Å passband - NASA

  Bright gas emission 1M K; cooler materials darkabsorbing structures 10k K.
sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_01 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_02 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_03 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_05
10 - Magnetic Field Lines Tangle as the Sun Rotates - The Babcock Model - A computer model illistrates one tangle cycle of ~11 years
US National Earth Science Teachers Association (NESTA) 2009 - SOHO (NASA & ESA)

  Sun Spots

  The first recorded observations of sun spots derive from direct visual sightings of Chinese astronomers at around 364 BC. More detailed accounts, not surprisingly, derive from around the time of the invention of the telescope in the late 15th century. Records exist from around 1610 from sightings of Galileo and some of his contemporise It has however taken nearly 500 years of observation, together with theoretical developments alongside, to come up with our present understanding as to what they are.
  Observationally, the dark spots we see on the photosphere of the sun are generally found to exist in pairs, or clusters of pairs, that have (often, but not always) a reverse symmetry, of similar pairs , or clusters of pairs; on the opposite hemisphere of the sun, divided by the solar equator. It is found that one spot of the pair exhibits a magnetic polarity of moment north (say), and that the other spot of the pair, the opposite moment, a south pole.
  It was in 1908 that the US astronomer G.E. Hale on examination of the spectra of hydrogen, from an area over a sun spot, discovered spectral line-spreading, termed the Zeeman effect, from which it was deduced that sun spots were magnetic phenomenon. What we now understand, graphically displayed in image data from solar telescopes, is that each spot represents the entrance or exit of an enormous grouping of magnetic fields. Magnetic fields which are driven by the dynamo effect of the sun’s rotating shell interacting with the electric fields generated by the ionised material within the turbulent convective cells of the suns convective zone; and there anchored, get twisted en-mass, to wind around the sun.
  It is quite staggering to appreciate the magnitude and extent of the magnetic fields causing the sun spots. These fields themselves are continuous loops that exist well outside of the sun; to have a section embedded in the sun’s outer shell, to spread out near the sun’s polar areas, to complete the loop up to as many as 50 A.U. away; driving the heliosphere current sheet (see above).
sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_06 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_08 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_09 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_10
  Sun Spots - Continued

  The differential rotation of the outer layers of the sun, from around 25 days at the equator to about 35 days nearer the poles, has the effect of winding the fields around the sun; with most of the winding occurring around the equator. As these magnetic fields get pulled around with the shell of the sun, kinks of loops from the same field, emerging on either side of the sun’s equator (as diagrams around), appearing where the fields pass through the photosphere, as sun spots. The spots, with little of the heated internal plasma in them, appear dark because they are cool spots on the photosphere, at around 4,500 K.
sun_aurora-4Sep2012_Northern-Hemisphere_David-Cartier_of-NASA_rivermirror-670_580w   The sun spots demonstrate a rough 11 year cycle in abundance; and in migratory movement across the face of the sun; before disappearing, to return again, for a similar period, but with the field in reverse. So only after a period of around 22 years do the same N-S sun spot poles appear in the same hemisphere of the sun.
  The sun spot cycle is coincident with a luminosity cycle that defines the sun as a star with a small variability. This variability has been noted to have some climatic effects on the earth. In times of high sun spot activity, the number of mass coronal ejections is increased, causing a high degree of magnetic disturbances on earth, and many aurora around the magnetic, and hence polar, latitudes.

Aurora in the Northern Hemisphere due to sun-spot activity,
4th September 2012
Rivermirror by David Cartier Sr; NASA

  A graph of sun spot activity over a period of observation started in the late 15th century, shows a period where sun spot activity virtually ceased (see below). The period of low sunspot activity between 1645 to 1717 is known as the Maunder Minimum; after the researcher and observer, Edward Maunder, who had suggested that a ‘new cycle’ of spots had started in the early 1700’s. Earlier period researchers, who had data just sufficient to glean the likelihood of periodic sun spot activity, had been stymied to draw positive conclusions, when the sun spots disappeared. Maunder had helped untangle the myth that, rather than there were no observations made during the lean period of spots, there were actually no spots to observe! During the period of Maunder Minimum, the earth experienced what has been termed The Little Ice Age.

  One might speculate as to the cause for a lack of sun spots during the Maunder Minimum. With what we know today, it could be deduced that the convective shell layer of the sun must have reduced to some minimum, below which magnetic entanglement with the dynamo fields generated in the layer, ceased to operate. It is unlikely that convective transport ceased in the outer layers of the sun; but more likely some change in the size of the granules of the convective cells; in theory, the larger the deeper one goes into the convective zone; so some change in cell morphology preventing magnet lock to occur.
6/3/2013 -
sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_11 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_12 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_15 sun_Magnetic-Field-Lines-Tangle-as-Sun-Rotates_SOHO(ESA+NASA)_2009-NESTA+mods-by-UCAR_17

10 - Sunspot Butterfly graph
April 2011; NASA, Marshal Space Flight Center, Solar Physics

  Butterfly diagram showing paired pattern of sunspots. Graph shows sunspot numbers.
  Spörer's law noted that at the start of an 11-year sunspot cycle, the spots appeared first at higher latitudes and later in progressively lower latitudes.
  Babcock Model explains the behavior described by Spörer's law, as well as other effects, as being due to magnetic fields which are twisted by the Sun's rotation.
10 - 400 Years of Sun Spot Observations - Summary of Sun Spot numbers since 1749
Global Warming Art by Robert A Rohde 2003

  The ~ 11 year solar magnetic cycle (re: number of sun spots) associated with the natural waxing and waning of solar activity is shown in blue (early period as red x's). General solar variability trend is shown as black trace.
  Included is the long Maunder Minimum when almost no sunspots were observed, the less severe Dalton Minimum, and increased sunspot activity during the last fifty years, known as the Modern Maximum. The causes for these variations are not well understood, but because sunspots and associated faculae affect the brightness of the sun, solar luminosity is lower during periods of low sunspot activity. It is widely believed that the low solar activity during the Maunder Minimum and earlier periods may be among the principal causes of The Little Ice Age. The Modern Maximum is between 1900 and 1950.

Notes: Continuous monthly averages of sunspot activity have been available and are shown here as reported by the Solar Influences Data Analysis Center, World Data Center for the Sunspot Index, at the Royal Observatory of Belgium. These figures are based on an average of measurements from many different observatories around the world. Prior to 1749, sporadic observations of sunspots are available. These were compiled and placed on consistent monthly framework by Hoyt & Schatten (1998a, 1998b).
Ref: Stott, Peter A.; Gareth S. Jones and John F. B. Mitchell (15 December 2003). "Do Models Underestimate the Solar Contribution to Recent Climate Change". Journal of Climate 16: 4079-4093
10 - Hendrik Avercamp paints scenes from The Little Ice Age of the early 17th Century
Winter Landscape (above) - Kunsthistorisches Museum, Vienna, Austria.
Winter Scene on a Canal (below) - Toledo Museum of Art, Toledo, Ohio, USA.

  Avercamp, Hendrick (b. 1585, Amsterdam; d. 1634, Kampen). Dutch painter, active in Kampen, the most famous exponent of the winter landscape. Avercamp was mute and was known as "de Stomme van Kampen" (the mute of Kampen). His paintings fall in the period known as The Little Ice Age.

The author would like to thank the astronomer author of Astronomy Today – Vol I 2005 (Chaisson – Mc Millan); More Precisely 16-1 Fundamental Forces; for the inspiration to use these images in this section.
10 - SDO - The Solar Dynamics Observatory satellite
SDO instruments (left); Spacecraft ready for loading on incertion booster (right); NASA

  SDO - The Solar Dynamics Observatory is a solar observing platform with updated capabilities on the previous SOHO (1996) and complimentary to the STEREO (2006) solar observer missions.

  Part of NASA's Living With a Star (LWS)  program, the stated goal is to:
    Understand, driving towards a predictive capability, the solar variations that influence life on Earth and humanity's technological systems by determining
  • How the Sun's magnetic field is generated and structured
  • How this stored magnetic energy is converted and released into the heliosphere and geospace in the form of solar wind, energetic particles, and variations in the solar irradiance.
  • SDO - The Solar Dynamics Observatory, NASA_SDO-beauty01+spacecraft_detailed_B_lum-NR+shp_914w_660h

  Some of the SDO's updated instrumentation is quoted as being:
  AIA (Atmospheric Imaging Assembly) - The Atmospheric Imaging Assembly images the solar atmosphere in multiple wavelengths to link changes in the surface to interior changes. Data includes images of the Sun in 10 wavelengths every 10 seconds. Alan Title; Lockheed Martin Solar Astrophysics Laboratory.
  EVE (Extreme Ultraviolet Variability Experiment) - The Extreme Ultraviolet Variability Experiment measures the solar extreme-ultraviolet (EUV) irradiance with unprecedented spectral resolution, temporal cadence, and precision. EVE measures the solar extreme ultraviolet (EUV) spectral irradiance to understand variations on the timescales which influence Earth's climate and near-Earth space. Tom Woods; Uni of Colorado.
  HMI (Helioseismic and Magnetic Imager) - The Helioseismic and Magnetic Imager extends the capabilities of the SOHO/MDI instrument with continual full-disk coverage at higher spatial resolution and new vector magnetogram capabilities. Phil Scherrer; Stanford Uni.
  The 2 high-gain antennas are Earth-tracking, maintaining as best contact with Mission Control, where-ever the spacecraft; as the craft, despite rotating in sync with the Earth, adopts a steady sun-pointing attitude.

  SDO launched on 11th February 2010, 10:23am EST, after a days delay due to weather; on an Atlas V that lifted from area SLC 41 at Cape Canaveral, Florida, USA. A large satellite by any standard, SDO massed at launch; spacecraft 1,300 kg (2,870 lbs), instruments 300 kg (660 lbs) and nav-fuel 1,400 kg (3,090 lbs); totalling 3,000 kg (6,620 lbs, 2.95 tons). Its 6.6 sq-m (71 sq-ft) solar arrays deliver 1,500 W at an efficiency of 16%, and extend 6.25 m (20.5 ft) across.

  The spacecraft was eventually boosted to a very near circular (eccentricity 0.00025) geosynchronous Earth orbit located over 102° W longitude, inclined at 28.5°.

10 - The Sun - Coronal Mass Ejection event - 1st August 2010
Combining data at three different extreme ultraviolet wavelengths
Solar and Heliospheric Observatory (SOHO) - European Space Agency (ESA)

10 - Solar Life Cycle - A G2V type Star & Time for Life on Earth
From Oliver Beatson 23 Nov 2009 (Adapted)

  The life history of the Sun, a common low mass star, over a few billions of years; from accretion as a G2V type star through its slow evolution to a red-giant (when it changes from fusing hydrogen, to fusing helium in its core), to a planetary nebulae (when running out of fuel, instabilities cast off its outer shell), to end as a naked white dwarf whence it will then fade away, over a further 10’s of billions of years, to become a cool black dwarf.
  The accretion of the solar system had the sun as the central body that first formed, with left over matter accreting in roughly circular orbits around it, in a disc. When the sun went into nuclear ignition, the radiant energy began clearing its surroundings of the finer dust particles. Gravity interactions then caused a large portion of the remaining matter to coalesce into mostly planetary bodies of varying sizes; one of which of interest is our Earth. Principal planetary formation is estimated to have taken about 220 million years after the birth of the sun. Some planets would migrate inward or outward, dependant on their starting mass, over another billion years or so; but that’s all planetary mechanics. However of interest to us here; the sun is estimated to be some 4.76 billion years old, with the earth having a slightly younger age of 4.54 billion years. Life on earth is estimated to have started 1.1 billion years after its formation, placing the beginning of life relative to the time line of the sun, as 1.32 billion years after the formation of the sun.
  As indicated above, the suns power output slowly increases with time, estimated to be about 10% per billion years. In about a billion years or so, the increased luminosity will be of such intensity as to boil away the planets oceans, making life on earth as we know it, untenable; that’s about 5.76 billion years after the birth of the sun. It is however possible that human industrial pollution may promote overheating due to 'the green house effect', which may overtake the planet long before changes in solar luminosity becomes an issue for life.
  It is estimated that when the sun becomes a red-giant in the next 5 billion years or so, that the inner planets, including the Earth, will be incinerated by the suns expanding atmosphere, an spiral by frictional drag into the sun.

  We observe that, the time for life on Earth, that is life (as we presently understsnd it) has a chance of survival, within the 'habitable zone' of such G type star systems, of around 4.44 billion years.
10 - The Sun - A Venus transit of the sun 2012
  From the Venus transit 5th to 6th June 2012. A bird landing on the Taj Mahal, Deli, India and the view from Sydney, Australia (both taken on the 5th June). Venus occludes the sun as a round dot at ~ ’10.5’ O’clock to the face as it transits the globe; the fainter dots are sun-spots.
[005 + 003] - Wednesday, 6th June 2012 @ 05.43-BST

  A week before this web page was started. Two beautiful images; a winner from Deli. The Sydney image on the other hand is a wonderful illustration of a phenomenon called 'limb darkening' by astronomers; We see deeper into the photosphere of the sun, where it is slightly hotter, when the sun is viewed directly over the middle; at the edges we view through more of the cooler photosphere; so the sun appears darker at its outer edges.
  With a major repeat occurrence of around every 243 years; as would be expected, the transits of Venus get a little complicated. Interspersed with a long gap varying between around 105 to 130 years, is a short 8 year repeat cycle. The astronomers have calendars, for those interested, of the precise dates projecting a few thousand years into the future.
  Of interest to those of simple science; the past cycle was 1874 + 1882; this cycle 2004 + 2012; leaving the next cycle well out of reach to most of us for - 10–11 December 2117 + December 2125.
  P-P chain
tla30_proton-fusion_thermonuclear_reaction_cc-astronamy-today_02 The thermonuclear Proton-Proton (p-p) chain reaction is a high temperature fusion process that is common to all main sequence stars. The process predominates in low mass stars, like the sun, as their operating temperatures are comparatively low. The p-p chain initiates at about ~8 to 10 Meg degrees K, with a power output that rises virtually constantly by exponent with temperature, but not as aggressively as a competing process, the CNO cycle, that will overtake it at around 16 Meg K, for stars that are more massive. The p-p chain converts hydrogen (11H; m = 1) into helium (42H; 2p + 2n; m = 4) with an output of energy, in a 3 stage process; where at each stage, a single proton (p) is effectively added to increase the mass of that stage by 1 mass unit. The process is illustrated below.

The p-p chain begins by fusing two protons (p) (nucleons of hydrogen-1) to produce a deuteron (n+p) (hydrogen-2, an isotope) + a positron (+e) and a neutrino (У)

a) 1H + 1H ―> 2H + positron + neutrino

The next stage converts the deuteron (n + p) into an isotope of helium-3 (p + 2n)

b) 2H + 1H ―> 3He + energy

The final stage converts helium-3 (2p + n) into helium-4 (2p + 2n). In reality it is achieved by the fusion of two helium-3 nuclei to give 1 helium-4 + 2 helium-1 + energy

c) 3He + 3He ―> 4He + 1H + 1H + energy

The simplified p-p chain equation combining all stages as follows:

d) 4(1H) ―> 4He + 2 neutrinos + energy
See the CNO cycle for an explanation of what happens to the ‘positron’, ‘neutrino’ and the ‘energy’.
  CNO cycle
 The Hans Beth’s thermonuclear CNO cycle of nuclear fusion, in large, high temperature, main sequence stars. A catalytic nuclear process, that progresses preferentially to the p-p chain reactions, because it produces more power at higher temperatures, than does the p-p chain process. It initiates at a temperature of around 12 Meg degrees K; as illustrated in the temperature plot.

 The CNO cycle converts hydrogen to helium; using carbon-12 (1212C) as the starting catalyst.

 Notice that all the intermediary products are next transmuted; to be returned as carbon-12.

12C + 1H  ―> 13N + energy
13N  ―> 13C + positron + neutrino
13C + 1H  ―> 14N + energy
14N + 1H  ―> 15O + energy
15O  ―> 15N + positron + neutrino
15N + 1H  ―> 12C + 4He


The neutrino’s immediately escape through the star, taking a small proportion of the energy with them.

The positron’s annihilate almost immediately with electrons into an electromagnetic photon of high frequency. The ‘energy’ liberated is also an electromagnetic photon of high frequency. All these photons, or gamma emissions, scatter randomly from the core, exciting nearby electrons and ions, thereby loosing their energy, to be re-emitted at slightly lower frequencies each time, to eventually emerge from the star’s photosphere at energies that make up the black-body emission spectra, including light, compliant to the surface temperature of the star.

The six stage CNO cycle may be displayed as one equation:

12C + 4(1H)  ―> 12C + 4He +energy

Which shows that hydrogen has been transmuted into helium.
10 - The Sun - Comparing the P-P chain and the CNO cycle.
Images adapted from Astronomy Today

  The thermonuclear synthesis of Helium-4 from Hydrogen-1. The P-P chain and the CNO cycle are the general steady state thermonuclear processes that first drive newly formed stars.
  It all depends on the starting mass of the proto-star and the purity (see matallicity) of the starting materials. There are other thermonuclear reactions that may ‘start’ a young star; but these may be peculiar to very very low mass stars or briefly transient for some larger mass configurations; so should be considered separately. The principal starting material of nearly all stars is a predominance of hydrogen. It is this hydrogen that provides the fuel for the first stage in nuclear reactions that drive the emissions of the star. As indicated above; in low mass stars the P-P chain predominates. For slightly larger stars like our sun, both the P-P chain and the CNO cycle will function, with the CNO cycle predominating. For larger mass stars, the CNO cycle dominates. Once in this condition, the star settles into a ‘main sequence’ condition (see later).
  The helium-4 produced may become the fuel for another stage in the life process of the star, provided it is massive enough; but that’s for a later story.
10 - The Sun - The visual solar spectrum showing absorbtion lines of many elements + The ideal plots (Intensity ver Rising Frequency) for Black Body radiators at different tempreatures; with the 5,778 K curve for the Sun (orange) - with the visual spectrum for comparison.
Adapted from Astronomy Today

10 - The Sun - BLUE Sunset, Castara, Tobago, TT - 19th July 2009

  Why is the sky blue? Called Rayleigh scattering after the British physicist Lord Rayleigh (1842 – 1919) who investigated the phenomenon, blue skies and red sunsets result from the property that the molecules of air are very close in size to the wavelength of blue light (400 nm), and so scatter ‘blue’ light. The visual (electromagnetic) spectrum, the peak black-body wavelengths of which derive from sunlight and to which all biological creatures of planet earth have evolved their visual sensitivity, ranges roughly from red (700 nm) to blue.
  It is interesting to note that life-forms evolved on different planets, under different suns, will ‘see’ in different wavelengths; but will be sensitive to the peak black-body wavelengths of their particular star. As to which stars may be amenable to the genesis of life-forms within their vicinity, is a different debate.
  The key to understanding what may be the confusion of scattering; is to simply recall that when a light-source is viewed (i.e. the sun), the direct light is scattered away from it; and when the view is elsewhere (not at the light-source) we now perceive that light which was scattered.
  A further subtlety is to appreciate that the sun’s light is incident all over the sky, so that everywhere one looks in the day-time sky; the sky is bright with scattered light (whoo!).
  The BLUE sunset is a mixture of two phenomenon; and whereas aesthetically disappointing for its lack of the expected ‘reds’ of a sunset, is as serendipitously as rear as a ‘spectacular red’ sunset because the intensity of the incoming light needs to be diminished by about 90%, to allow re-mixing, for the phenomenon to occur.
  With an overcast sky extending virtually to the horizon, there is very little direct sunlight. The low intensity of the direct light from the area of the sun and with the re-mixing of the scattered light, it is now a homogeneous mix of the visual spectrum, a mix of all colours, which is perceived as ‘white’. All the other light however, is scattered light, the colour of the sky, a colour that Rayleigh’s calculations indicate will be about ~10 times more intense at the ‘blue’ range of the spectrum. The predominant colour is ‘blue’.
10 - The Sun - RED Sunset, Castara, Tobago, TT - 13th January 2010

  The RED sunset is a phenomenon of direct scattering. Through a clear sky, Rayleigh scattering of the direct light (see above) by the molecules of air, has taken out most of the blue region of the visual spectrum; the ‘reds’ dominate. The sun’s peak black-body wavelength of ‘orange’ however, dominates the colour of its globe. Now on the horizon, and viewed through a very thick layer of air, the intensity of light is reduced for more comfortable (and less dangerous) viewing, scattering is at a viewing maximum, intensifying the ‘reds’.
  Over the sea, evaporated water-vapour molecules adds its scattering to the glory of a sunset-over-sea, and intensifies the ‘reds’ further. Dust in the atmosphere, particularly volcanic ash, which may be stratospheric and affect grater depths of atmosphere through which the light of the horizon has to pass, by other calculations cause a further scattering of the higher frequencies of light by an order of 1.5 times. Now more ‘orange’ is scattered out of the remaining incident light and spectacular ‘red’ sunsets result.
  Clouds in the local area can dramatise the sunset by reflecting the hues of the in coming light.

  An elusive ‘green flash’ that may be observed to occur before sunrise, or after a sunset, is a real phenomenon and prismatic; but is very rarely seen because of the timing of the odd atmospheric conditions that are necessary. The light reaching the observer comes from the edge of the sun, under the horizon, usually via a temperature inversion in the atmosphere. The atmosphere is now acting like an inverted prism, in the up-down direction. It bends the shorter wavelengths, violet, blue and green (in that order), more strongly than the yellow, orange and reds. So the order of disappearing light (at sunset – the reverse occurs for sunrise) is; red, then orange, then yellow will go out; next will be green. But the blue and the violet have been scattered out; leaving predominantly the ‘green’ to provide the last ‘green flash’.
The Terrestrial planets - Mercury, Venus, Earth and Mars

The Terrestrial planets compaired by size - Mercury, Venus, Earth and Mars
10 - The Terrestrial planets compaired by size - Mercury, Venus, Earth and Mars

Mercury - Surface in composite wavelengths of 1000nm, 700nm, and 430nm mapped by MESSENGER (03-07-2004) orbiter post March 2011_605w
10 - Mercury - Surface in composite wavelengths of 1000nm, 700nm, and 430nm
Mapped by MESSENGER orbiter (Launch 03-07-2004); Post-March 2011



Venus - In true colour (left), ultraviolet (right) by Pioneer Venus 1 (20-05-1978) orbiter, to reveal detail of cloud vortices under the haze in 1979_990w
10 - Venus - In true colour (left), ultraviolet (right)
(Right) Imaged by Pioneer Venus 1 (Launch 20-05-1978) orbiter, to reveal detail of cloud vortices under the haze in 1979

Venus - Global radar view of the surface imaged by the Magellan Orbiter (launch 04-05-1989) between 1990-1994_600w
10 - Venus - Global radar view of the surface.
Imaged by the Magellan Orbiter (Launch 04-05-1989); A composit of data gathered between 1990 to 1994

Earth - Gaia, Tellus, Terra, Sol III

earth_google-earth_Pacific ocean view_03 (squeeze 990 x 701)
10 - The Water Planet - Earth - An unusual oceanic view - The Pacific Ocean.
Google earth 2014 - SIO, NOAA, US Navy, NGA, GEBCO; US Department of State Geographer by Landsat

Earth - The western hemisphere Blue Marble 2012_VIIRS instruments aboard NASA's Suomi NPP satellite_6760135001_14c59a1490_o_990w
10 - Earth - The Western hemisphere; an image called the 'Blue Marble 2012'; a beautiful rendition of Earth, but not unexpectedly, a culpably Americentric choice by NASA.
A composite from the VIIRS instrument aboard NASA's Suomi NPP Earth observing satellite, 04/01/2012 [Updated Flicker: 02/02/2012]
  The currently accepted age of the Earth is 4.54 Giga years ± 1%

Earth – Single photo from geosynchronous orbit at 36,000km (22,379mi) - Russian weather satellite Electro-L at 121 megapixels 11 May 2012 (published by MailOnline)
10 - Earth – Single photo from geosynchronous orbit at 36,000km (22,379mi)
Russian weather satellite Electro-L at 121 megapixels 11 May 2012 (published by MailOnline)

Earth_The wealth of a Planet_euroasia + africa + australia_03_el-4800-ext_1366w_1156h
10 - Earth - The Wealth of a Planet. The Principal land masses. Euroasia, Africa and Australia.
Composite images of the Earth at night. Defense Meteorological Satellite Program (DMSP), Operational Linescan System (OLS);
Base image courtesy: ~2002 (Marc Imhoff; Christopher Elvidge) NOAA, NGDC, NASA.

Earth_The wealth of a Planet_oceania_02_el-4800-ext_1366w
10 - Earth - The Wealth of a Planet. Oceania and The New World (right).
Composite images of the Earth at night. Defense Meteorological Satellite Program (DMSP), Operational Linescan System (OLS);
Base image courtesy: ~2002 (Marc Imhoff; Christopher Elvidge) NOAA, NGDC, NASA.

10 - Earth - China + Korea + Japan - Notice the disparity between South and North Korea (see North, over the Southern tip of Japan).

10 - Earth - The Korean perninsula - North Korea (in absentia) from space.
The lonely shine of capital Pyongyang only emphasising the squander of the wealth of a nation.
From the International Space Station (ISS); 30th January 2014; NASA-JSC & Reuters

10 - Earth - Europe + North Africa. Note Moscow, the heart of a spiders-web to the East.

10 - Earth - South East Asia.

10 - Earth - Australia, Tasmania and New-Zealand.

Earth_The wealth of a Planet_north america + caribbean_01_el-4800-ext_1366_768
10 - Earth - North America (with Alaska & Hawaii) and the Caribbean.

10 - Earth - Lower Mexico, the istmas of Panama and the Caribbean.

10 - Earth - South America.

10 - Earth - Western Asia and India.

10 - Earth - Africa - The most under-developed Continent.

The estimated population of Africa is 1.267 Billion or 16.41% of the total World population (7,578,909,220).
Africa ranks as number 2 (1, China, 1.411 Billion, 18.67%) ordered by population numbers for world regions designated as 'Continents'.
Data: www.worldometers as of Saturday, 4th November 2017, based on the latest United Nations estimates.

10 - Earth - The Nile Delta and the Middle East - An area in conflict.
The Nile River; The bright lights start downstream from the Aswan Dam and follow the contour of the river to the Mediterranean Sea.

10 - Earth - World Population Data.
2012 World Population Data Sheet; Population Reference Bureau.

Endeavours on Earth

Down Foot-Notes to THE LAST ATOM Up Top
An endeavour of species Homo Sapiens
A selective history from the early period of the advancement of nuclear science

  This story begins with the birth of a star, which is quite ironic. Because it begins quite accidentally, as it was not planned as the beginning, the beginning of something else; a something else that just happens to be the focus here, the story of stars; so as a beginning, that’s not too bad for a beginning. It should be about heroes, but they are too tragic; so something else has to do. So its about the stars that make stars shine in quite a different kind of way. It’s not easy to be a star, because something special has to shine to be a star in any type of story. These are stars from the history of species Homo Sapiens, a sentient animal evolving on planet Earth; not the 3D kinks kind, but real people. These stars are the “My future’s so bright; I just got’ta wear shades” kind, really bright; least we forget, right down to the last atom.
W. Thomson (Kelvin); H. von Helmholtz; Archbishop J. Usher
Stellar formation, age of the earth


Protostars glow dissipating the gravitational energy of formation as their gas is heated by the compression of collapse. This is called the Kelvin–Helmholtz contraction phase, named after Lord Kelvin (William Thomson - 1862) and Hermann von Helmholtz (1856), both European physicists, who provided calculations based around the gravitational compression of gasses and the cooling of a molten earth, in an initial attempt to calculate the age of the earth.  An argument that had all been started by one of the worlds most famed idiots, the Archbishop James Usher of Armagh, Ireland, in 1650; suffuse with dogma and clouded in ignorance, declared that the universe was created in 4004 BC, on such a day and at such time worth forgetting; least the number 5,654 years ago (@ 1650). A very poor guess. It was a vexing and perplexing problem, as the ages thoughtful calculations offered were falling far short of the preliminary estimates coming in from the geologists and palaeontologists of the day, who were theorising from their standpoint of their understanding of the processes for sedimentary deposits; and from the evidence of the materials and fossils they were collecting in the field. Gravitational collapse, and even chemical burning, could not provide the energy for a glowing sun for the estimated 100’s of millions of years, and at that time just moving into the billion, that the budding science of planetology required. More frustratingly, there was as yet no known process by which geological time could be reliably estimated.

 There began one of the most intense and exciting periods of scientific enquiry, that in its first phase of a short 40 years or so, propelled the planet from a sedentary classical Newtonian view of the mechanical universe, to evolve into the dubiously promising, continually mismanaged, but necessary age of the atom. Chemistry was to be explained as a phenomenon of electricity, and a new world of quantum probability was to be borne.

I. Newton, G.W. Libniz, C. Wren, R. Hook, E. Halley, S. Peppys, M. Faraday, J.C. Maxwell, G. Galilei, J. Kepler
Retrospective; derivative calculus (Fluxions); Light, Opticks, experimental science , elliptical orbits, Laws of motion, gravitation, Principia;
electromagnetism, Maxwell’s field equations, electromagnetic waves, speed of light, electromagnetic spectrum


In a hurried retrospective we may recall that the English philosopher-physicist Isaac Newton began to conceive in 1666 the laws of refraction of light, and an explanation for the dispersion of light into the colours of the rainbow. He released his findings to the Royal Society in 1672; but because of much criticism, did not allow the publication of the rules of optics that he had devised, titled Opticks, until 1704. Newton, putting it a little more kindly than perhaps he deserves; was at once a genius of the first rank and also the first ‘geek’ of physics, disorganised, and an eccentric recluse; the proverbial example of the street-dumb ivory tower ‘Don’. Also beginning in 1666, when he was at his mothers home in the country for two years, to avoid the bubonic plague that ravaged the cities, he devised in secret, what he called Fluxions, what we now call derivative calculus, to support his work on gravitational attraction that he had then begun to develop. He got into another row with the mathematician Gottfried Wilhem Libniz whom Newton could not believe had independently also derived derivative calculus when Libniz version was published in 1676. The then heavyweight British establishment acceded in Newtons favour, so that this branch of mathematics is now accredited  to both Newton and Libniz. Newtons pinnacle contribution to science; his laws of motion, enlarging on the understanding of the 1632 works of the Italian Galileo Galilei, considered by many as the founding father of experimental science; his laws on gravitational attraction, explaining the laws of elliptical orbits, so crucial to astronomy, as proposed by the German mathematician Johannes Kepler in 1594; may have remained buried in the Cambridge archives for another century, had Newton not been harried from the outside.

tla10_electromagnetic-radiation_astronomy-today_03  To settle an argument between the architect Sir Christopher Wren, physicist Robert Hook and the astronomer Edmond Halley (later of cometary fame); in 1684 Halley came from London to Cambridge to consult Newton. Asked what he thought the course of the planets would take around the sun, if the force of attraction was inversely proportional to the square of the distance between them, Newton quickly answered in his customary way, ‘been there, done that’ and the answer is ‘elliptical’. Incredulous to the rapidity of the response, Halley asked where was the proof? It took three years for Newton to write, after much badgering and even financing from Halley, and included the solutions to much else, before Halley finally handed the completed Principia to the president of the Royal Society, Samuel Peppys, in 1687. That the work was sensational, would be an understatement; its laws underpinned the industrial revolution of the planet and survived for over 200 years, before needing modifications to accommodate the laws for objects moving near the speed of light, and for a better understanding of light itself, when the concept of space-time was to arrive in 1905.

Another outstanding precursor to this new age, out of many others that were however necessary in foundation like, Michael Faraday the electrical hardware man, was the complimentary work of the Scots mathematician James Clarke Maxwell, who unified electricity and magnetism in 1860 with what are now known as Maxwell's field equations. It rigorously postulated that an electric field, orthogonal (at 90 degrees) to a magnetic field, oscillated together in a sinusoidal way to produce electromagnetic waves that propagated at a calculable speed. The strength of any new theory is in its ability to predict measurable results. Maxwell's field equations went way beyond this simplistic criteria; as to some observers, the elegance of the mathematics also accomplished an inherent beauty that approached art; and that the manipulation of the mathematics produced much more than just one startling result. The result that the speed of electromagnetic waves turned out to be around 300,000 km/s (≈ 186,000 mi/s); which just happens to be the measured speed of light en vacuo, would have been sensational enough to mark the achievement as 'epic'. The tying of light to a narrow wave-band lying within that enormous range of the electromagnetic spectrum that encompasses kilometre long-wave radio waves at one end and the short fempto-meter gamer-rays at the other. But no, that was just the beginning of what followed.

Maxwell's field equations are the bases for communications and transmittable (& receptable) energy engineering; their astute manipulation predicting all the necessary control algorithms within the disciplines of AM, FM, TV, micro-wave and RADAR, just to highlight a few of the better recognised within this vast field of work; which also purveys into astrophysics and astronomy. Simply in scope, Maxwell's field equations define the term 'awesome'.

Röntgen, H. Becquerel, J.J. Thompson, E. Rutherford, M. Curie, P. Curie, P.V. Villand
The atom; X-rays, cathode rays, electrons, ‘plumb pudding’ theory of atom;
radioactivity, radium, polonium; alpha (α) , beta (β) + gamma (γ) rays


The new age of discovery centred around the effort to understand the composition of the atom, which comes from the Greek ἀ- (a-, "not") and τέμνω (temnō, "I cut") or collectively ἄτομος (atomos), which means "indivisible"; and by default, molecules. Although chemists had for years successfully manipulated elements and their molecular constructions, they still remained at a loss to understand the underlying processes that quantified the behaviour of the elements they were dealing with. It was now the turn of the physicist and theoreticians to provide the useful answers.


It was in 1895 that Röntgen, using cathode rays, discovered unusual penetrating radiation that showed the bones in his hand which shadowed a phosphorescent screen. Coining the term X-rays, he could not explain them. Henry Becquerel heard about them in 1896, and after a few false starts, by the middle of the year demonstrated that they were also the product of a uranium salt that fogged a photographic plate. On a slightly different track, in 1897 the physicist John Joseph (J.J.) Thompson demonstrated that cathode rays were in fact a manifestation of particles, with a negative charge, that he called electrons, the weight of which he measured to be 1836 times lighter than the lightest particle then known, the mass of the hydrogen atom; and over the next 10 years developed his ‘plumb pudding’ description of the atom; a ball composed of mixed positive and negative charge. On his way to probe the mysteries of the atom, the physicist Ernest Rutherford started his investigations of Becquerel’s phenomenon in 1898. At the same time Mem. Marie and her husband Pierre Curie began their arduous task of chemically extracting and identifying the elements that produced Becquerel’s rays and named the phenomenon radioactivity. The Curies discover a new element, a strong emitter for this activity, they name it radium. They also discovered another new radioactive element, which they named after the country of Mem. Curie’s birth, polonium. By 1899 Rutherford, using the elements uranium and thorium, defines the radioactivity of the elements as the emissions of alpha (α) and beta (β) rays. (P.V. Villand, a French physicist, later described gamma (γ) rays, so named in keeping with Rutherford’s scheme, as a third type of high energy emissions emanating from radioactive elements.)
M. Plank
Quantum Theory, quanta, the ultra-violet catastrophe, black-body radiators, Planks constant

In 1900, a new Quantum Theory on the behaviour of energy, indicating that it would be manifest in discrete amounts, or quanta, was published by the German theoretician Max Plank. Plank used quanta to resolve the ultra-violet catastrophe that had belied classical physics in explanation for the spectrum of energy emitted by black-body radiators.

Strongly showing the crack at the link between thermodynamics and electromagnetism in classical physics, arose the conundrum known as the ultra-violet catastrophe. The link is that temperature can manifest itself notably with dark (cold) or shiny (hot) objects; as in the black body radiator (or absorber) that physicists use as a benchmark; temperature shows as light, which is electromagnetic radiation. The crack arises in explanation for the spectrum of radiation emanating from a black body radiator, where the classical theory required that the upper frequencies move to infinity, and there-by inherit infinite energy; and that was just ‘over the top’. Plank’s quanta, discrete packets of energy, showed that instead of a continuous run of energy, brought sensibility through the statistical probability that only a few quanta would carry the high and the low energies, most averaging with energies around the specific temperature; and thus provided the required limits. Energy is in packets; E = hf, where f is the frequency of the electromagnetic radiation and h became Planks constant. With a value of h = 6.63 x 10-34 Jule-seconds, of such tiny dimensions; it also brought an uncomfortable but staggering realisation, that there was a whole new micro-universe to explore; and Plank’s mathematical scalpel, was just one of the many such new tools needed to explore it.

E. Rutherford, M. Curie, P. Curie, F. Soddy, M. Todd, A. Einstein
Radium, radiological hazards, spontaneous disintegration of radioactive elements, isotopes, ‘half-lives’, ‘decay products’, uranium,
‘time’ to the geologists, tracing…chemists…identify…elements, size of atoms and molecules,
Photo-Electric effect, duality of light to be both a particle and a wave, quantum mechanics, photon,
Special Relativity, space-time, energy-mass equivalence, alpha (α) particles… nucleons of helium


Ernest Rutherford visits the Curies in Paris in the summer of 1903, on the same day that Marie receives her doctorate. At the end of the evenings celebrations, he is shown a vile coated in zinc sulphide, containing concentrated salts of their newly discovery radium. The vile enchantingly glows brightly white, in scintillation to the stream of radiation exciting it. It is bright enough for Rutherford to later comment that he observed, in its light, that Pierre Curies hands were scared and reddened by such activity. Ever observant, as was his character; little did he realise at the threshold of this science, the dangers to which they were all subject. Mem. Marie Skladowsha Curie would later die of leukaemia (4th July 1934); and all her laboratory papers and other memorabilia, consigned to lead containers for posterity. [The medical sciences that were to eventually qualify the true extent of radiological hazards to biological systems, would take a further 50 years to be properly developed.]

 Rutherford, together with Frederick Soddy the chemist, went on in 1903 to describe the spontaneous disintegration of radioactive elements and developed the theory of radioactive decay and its inherent time marker of ‘half-lives’. Soddy used the term isotopes , a descriptor ascribed to one Dr. Margaret Todd, to distinguish between mass differences of the same element, that would themselves demonstrate different ‘half-lives’. They went on, in the infancy of the science, to glean the remarkable range of time differences in the ‘half-lives’ of various ‘decay products’ of radioactive elements; from fractions of seconds, to a staggering 4.5 billion years for an isotope of uranium. Their investigations handed the elusive grail of ‘time’ to the geologists and, when used the other way around, ‘half-lives’ to identify specific elements, or indeed new elements, for the chemists. Much of the investigative work that was to follow, well into the late 1930’s, on new elements and their isotopes, created by their bombardment with nuclear emissions, was based on ‘half life’ detection; and then tracing the minute quantities of the elements thus formed; through various chemical separation stages that would then identify the resulting elements.

Between 1904 and 1905 Albert Einstein, a Swiss patent office clerk, published four papers. The first, on Brownian motion, and the second, his doctorial thesis in which osmosis is investigated; used classical statistical mechanics that allowed investigators to establish the size of atoms and molecules. The third paper, for which he received a Nobel prize in 1922, explained the Photo-Electric effect in quantum mechanical terms; as the duality of light to be both a particle and a wave, where the wave is a photon, and the photon a discrete quantum unit of energy, and the energy of the quantum unit is proportional to the frequency of light, leading photo-voltaic effects to be proportional to light frequency, rather than light intensity. The forth paper, on Special Relativity, conceived around the perceivings of two observers placed at different points relative to each other within the frame of reference; that changed the perception for the laws of motion of a particle in a straight line; where that the speed of light is a constant and the maximum speed at which only light can travel, where space-time, the fabric of the universe, uses time as its 4th dimension; where for an observer approaching the speed of light, the time slows, lengths shrink and mass increases. It was so esoteric, that it would take the scientific community a while to digest that their world had changed. Further surprises were in store. In 1907 he presented a paper in which the duality of energy and matter is explained; deriving that yet to be, after 1919, the most famous equation of the 20th Century, e = mc2, the equation of energy-mass equivalence.

In 1908 Rutherford received a Nobel prize for his investigations. It was for chemistry, and not physics; a skewed distinction of merit that much amused him. During his speech at the academy, he announced that he had recently confirmed that alpha (
α) particles were in fact nucleons of helium.

C.T.R. Wilson, Glaser, H. Geiger, Müller, E. Marsden, E. Rutherford, Copernicus, J.J. Thompson
Wilson cloud chamber, bubble chamber, Geiger-Müller tube…counters,
‘plumb pudding’ model, Rutherford model of the atom


Invented in 1911 at the Cavendish laboratory, Cambridge, C.T.R. Wilson constructs a glass cloud chamber. Inside an upright glass cylinder with a glass top for viewing and sitting in a water tank to saturate the air inside with water vapour; floats another capped inverted cylinder, of specific dimensions, with its bottom open to the water, acting as a piston. Up the middle of the tank and into the piston cylinder, is a tube connected to a vacuum system. On activation of the vacuum system, the piston slams to the bottom of the tank, expanding the air in the main tank by adiabatic volumetric expansion to the required order of 1.31 to 1.38. Energetic particles (from a radioactive source, say) are injected into the saturated vapour chamber from the side, and the activity viewed through the top. Only if the source particles and any daughter particles that may result from experimental collisions, are of the type to ionise (remove an electron) from the molecules of air; their track within the chamber become a vapour trail trace of tiny drops of water, coming out of saturation, formed around the ionised air. From photographs; measurements of track lengths and angles of diversions following collisions yield data on momentum, energy and infer the type of particles that formed the (or intermittently did not) traces. When placed in a magnetic field, charged ionisation particles curl in opposite directions, dependant on their charge. The Wilson cloud chamber did ‘Stirling’ work in the earlies’. Its successor, Glaser’s bubble chamber of 1951, along similar principals, uses fluids instead, and liquefied gasses like hydrogen, and generates tracks of bubbles; and are suited to higher energy particle experiments using particle accelerators; liquid density infers shorter tracks from higher energies, that would otherwise overwhelm a gas device.

 Using data from experiments provided by his assistants Henri Geiger (who would later work with Müller to develop the Geiger-Müller tube and GM particle counters) and Ernest Marsden, in which they found that a thin foil of gold bombarded by alpha particles not only diverted the particles by a small angle at the other side of the foil; but also bounced the particles back off the foil like a “fired shell”. Rutherford with electro-magnets on pendulums modelled the results, and concluded that the nucleus must be very small and very dense. From this evidence, in 1911 Rutherford, borrowing an old model from astronomy first set by Copernicus (1543), described the atom as comprising a positively charged nucleus around which orbited the negatively charged electrons. Thompson’s homogenous ‘plumb pudding’ of particles now morphed into Rutherford’s ring of electrons circling mostly empty space, in the centre of which lay the positively charged nucleus of the atom.tla26_atom_lithium_stylised_02.jpg

But what needs to be understood here, are the subtleties of the change in this visualised model. The Thompson’s homogenous ‘plumb pudding’ model visualised a ball of mixed particles at the position of the atom. The Rutherford model visualised a cloud of electrons spinning around a small nucleus; so now at the position of the atom; was at first a cloud of electrons, then some empty space, then a small positively charged ball at the nucleus. How much empty space, and the size of the ball, no one really knew. It was this space and the ball of the nucleus, that became the puzzle to be sorted out. The ball was positively charged, the ball was heavy, what was in it? Was it a ball at all?

Although a constructive, useful and a convenient first step in visualising the structure of the atom, the Rutherford model immediately ran into a problem that ‘classical’ physics of the day could not handle. Although the countering analogy itself is somewhat flawed; the idea of charged electron particles busily whizzing around the nucleus invoked a requirement, through the conservation of energy; that they radiate energy, thereby loosing momentum, and in consequence, would eventually crash into the nucleus. That atoms do not normally glow, and that normal atoms appear stable; is proof enough that the mathematical constructs of the day were inadequate to explain the observations.

Niels Bohr, D.I. Mendeleev
Planks quantum theory, quantum states of energy levels, ground state, Bohr-Rutherford model,
Spectroscopy, Rydberg’s constant, Paschen, Balmer and Lyman series
Pauli’s exclusion principal, Periodic Table of the Elements, Physical chemistry, valency


In 1911, the Danish theoretician Niels Bohr using Planks quantum theory redefines Rutherford’s atom as a +ve nucleus surrounded by a number of –ve electrons; that the electrons reside in specific quantum states of energy levels. That the electrons excited by incoming photons will only absorb the energy in specific units of tla24_spectral-lines-of-sodium_emission+absorbtion_cc-astronamy-today_02quanta that allow them to reside in a different, but specific energy level, determined by multiples of Planks constant, h. That by absorbing photons, the atom is excited, where the electrons move up to higher energy levels; and conversely, by emitting photons, fall back to lower energy levels. For an unexcited atom, the electrons occupy the lowest state of energy excitation, being defined as the ground state for the electrons. 

The Bohr-Rutherford model (as it was later called) was however limited to the description of the simplest atom, hydrogen with 1 electron, as it could not adequately explain the behaviour of atoms with more electrons, needing further developments of quantum theory to do so. However, it immediately explained the underlying principals of Spectroscopy, where absorption lines show the frequency of the photons, in units of quanta, as the electrons absorb the in-coming energy and jump to higher permitted energy levels. Where emission tla25_spectral-lines-of_molecular+atomic-hydrogen_emission_cc-astronamy-today_02spectra show the reverse; where the emitted photons, out-put energy at frequencies related, in quantised units, to the lower permitted energy level to which the electrons fall. So the multiplicity of spectral lines for each element, represent the movement of electrons from any permitted energy state to another, provided that there is no electron occupying that state in the first place. Hence each element has its own specific spectral signature.

 Bohr’s quantum treatment of the atom allowed him to calculate, from first principles, a constant that had been determined previously by experimental physics called Rydberg’s constant; it also derived the spectral equations of hydrogen that had been laboriously produced from experiment and named after their discoverers; the Paschen (infra-red), Balmer (visable) and Lyman (ultra-violet) series.



After 1913, Bohr and others applied further quantum refinements to his model, and with the adaptation of Pauli’s exclusion principal, it then began to explain further, the behaviour of the elements. That for each specific element, where the number of protons is matched by an equal number of electrons to balance the charge; as the proton/electron count rises, the electrons begin to occupy quantised energy shells, around the atom, which are first filled, and are then required to fill a higher energy shell, an so on, all the way up to the heaviest elements known. And all shells filled in relation to some quantum order. Bohr’s adapted model of the atom defined where an element would reside in an extended version of the Russian chemist Dmitri Ivanovich Mendeleev’s (1871) Periodic Table of the Elements; as the columns are defined by the successive steps in filling of the quantised shells; and the rows defined by the number of filled shells. Physical chemistry is thus explained as the behaviour of the outer shell electrons of one atom – the valency - interacting with the electrons of another atom, or a collection of atoms (atoms of the same or different elements does not matter here), seeking to balance their energy distribution to the lowest possible quantum state accorded for the outer shell, by shearing each others electrons.

  Page update (2017) to the recently named Elements (112 - 118).
Date first
Date accepted
by the IUPAC
Polish astronomer Nicolaus Copernicus
common Japanese name for Japan (日本 nihon)
Russian physicist Georgy Flyorov
named after the Moscow region, in which the Joint Institute for Nuclear Research (JINR), Dubna, Russia is situated
named after the Lawrence Livermore National Laboratory, California, USA
named after the state of Tennessee in the USA
Russian physicist Yuri Oganessian

  Return to Nuclear Periodic Table (below)
A. Einstein, H. Minkowski, M. Grossman, B. Riemann, B. Christoffle, G. Ricci, T. Levircivitá
geometrical treatment, Special Relativity, non-Euclidean curved geometry, tensor calculus
General Relativity, theory of gravity, model for the universe, acceleration is equivalent to gravity,
stimulated emission, LASER


In 1914 Albert Einstein began to make a serious effort towards completing his theory of General Relativity, but he needed better mathematics than he understood at the time to do so. His early mathematics lecturer Hermann Minkowski had in 1908 applied a geometrical treatment to the theory of Special Relativity that Einstein had studied in admiration; but for the concepts in his head, he felt he needed different tools. That year he turned to his childhood friend, Marcel Grossman who had made exemplary notes of lectures that Einstein borrowed after the times he went truant, now a professor of mathematics; and asked him for his help. Grossman worked with him and his half completed General Relativity by introducing him to the mathematics of Bernhard Riemann of non-Euclidean curved geometry; and to tensor calculus as pioneered by Bruno Christoffle, Gregorio Ricci and Tullio Levircivitá. After a further year of effort, Einstein had completed his next masterwork.

 General Relativity is a theory of gravity; and by default, also provides a model for the universe. Special Relativity is a sub-set, or special case, of General Relativity as it only deals with matter at rest, or moving in a straight line. General Relativity deals with matter in motion, changing direction, accelerating, gravity fields.

 General Relativity rests on the premise of another idea of equivalence that Einstein conceived. It is based on the idea of a falling object, like a man falling in a lift, who is accelerated by the force of gravity; but who is also weightless. So the accelerating force and the force of gravity are equal and equivalent. So acceleration is equivalent to gravity. So the idea builds another thought experiment. If a man (excuse the sexism) shines a light on one side of a weightless lift, the light will strike the opposite wall in a straight line. If the lift is now however on a planets surface, it is now in an accelerating field, everything in the lift is affected by gravity; the man and the light. So the man stands apposing the force of gravity on one side, and the light falls in an arc to hit the wall lower on the other side. General Relativity set out to prove this. The resulting construct is of curved space applied to the space-time of Special Relativity. Gravity, acceleration, bends space-time.

The theory of General Relativity was first presented in three lectures at the Prussian Academy of Science, in Berlin, around the 25 November 1915. The lectures were presented as “The field equations of Gravitation”. In his presentation Einstein commented as to his assessment of how far he thought his commitment to this project had gone, with “…finally the general theory is closed as a logical system.” So there it was, finished. It was later published in 1916. The emergence of one of the worlds greatest mathematical tools in 240 years had little impact, except to a handful of enquiring minds, because after all, it was complicated and rather esoteric; and Germany was at war (1915 to 1918). However, General Relativity was now subject to proof.

Returning to his theoretical work using quantum theory, in 1917 Einstein expanded the theory on the behaviour of electrons, using a simplified Bohr model, where the electron becomes excited by a quantum of energy, the photon. He considered that it would behave in three ways. On excitation, the electron would jump to a higher energy level, provided the frequency of the photon matched an available higher energy level of the atom. But the de-excitation could happen in either of two ways. Either the electron would fall spontaneously to a lower energy level, releasing the absorbed photon to go off in a random direction; or the electron could be immediately de-energised into stimulated emission by the arrival of a photon of the same frequency, in which case the photon would leave in wave synchronisation and direction of the stimulating photon. This was the fundamental theory that was to be applied some 50 years later in the application of LASERs (Light Amplification by Stimulated Emission of Radiation).

F. Dyson, A.S. Eddington, C.R. Davidson, Littlewood, B. Russell, A. Whitehead, J.J. Thompson, O. Lodge
E. Hubble, J. Bronowski
proof of General Relativity, solar eclipse 29th May1919, Principe Island - west Africa, Sobrol - Brazil
The Royal Society, Greenwich Observatory, 3rd June 1919, Completely confirmed,
6th November 1919, “One of the greatest achievements in the history of human thought.”
7th November 1919 headlines of The Times read REVOLUTION IN SCIENCE


The British astronomer, Sir Frank Dyson, in 1917 was aware that the bending of light by the sun would offer proof of General Relativity; and suggested that a solar eclipse, due in 1919, would be the ideal opportunity to test it. Dyson determined that the best view for this eclipse would be on Principe Island, off the west coast of Africa; and to have a back-up in case of poor weather, Sobrol in northern Brazil. With a war on, funds were short; but he started plans for an expedition.

 Luckily, the war appeared ended with the Armistice of November 1918 which had halted the fighting, and political thoughts, as usual presumptuous, considered a British effort to prove a German physicists theory, good ‘brownie point’ propaganda for Britain; and if the theory correct, extra ‘brownie points’ for a defeated Germany; funding was found for the project.

 The Cambridge astronomer Arthur Stanley Eddington would lead the Principe group, and the Greenwich Observatory would send C.R. Davidson and team to Sobrol. Six months before the eclipse, a photographic survey of the area of the sky in which the sun would lie during the eclipse, was made for reference. Both teams had good viewing, and the solar eclipse of 29th May 1919 was successfully photographed from both locations.

tla30_proof-relativity_bending-of-light_adapted-astronomy-today_AACHDFZ0_01 The photographs were developed abroad, and by the 3rd June Eddington, who would have taken reference plates with him, knew that Einstein was right. He telegraphed to The Royal Society with the news. It spread like wildfire; as a consequent message from the mathematician Littlewood of the R.S. to the philosopher mathematician Bertrand Russell records:

 “Completely confirmed: Predicted 1”.72. Observed 1”.75 ± 0.06.”

Before any public announcement, all the data had to come in from the field, and further measurements made to dispel any errors. Also the war was not yet officially over. However, The First World War ended on the 28 June 1919, 8 months after the Armistice of 10th November 1918.  A release of the news would bring some cheer to a battle worn Europe.

 So virtually a year after the Armistice, on the 6th November 1919, at a joint meeting of the Royal Society and The Royal Astronomical Society at Birlington House, London, with a Times correspondent in attendance; the announcement was made in the proportions of ‘a Greek drama’, as described by the philosopher Alfred Whitehead who attended. To a packed hall awaiting in silence, J.J. Thompson the president of the Royal Society, rose to make the address, pausing to glance up at the portrait of Newton that hung above them. Thompson began “One of the greatest achievements in the history of human thought.” Using euphemisms of Empire “It is not the discovery of an outlying Island, but a whole continent of new scientific ideas.”

 The Astronomer Royal, Sir Frank Dyson, then rose to outline the results from the Eddington and Davidson teams. In verification of Einstein’s theory, he stated that the bending of light by the gravitational effect of the sun did not tally with the theory of Newton, but was in full accord and near exact agreement with Einstein’s theory of General Relativity.

A lively debate then followed, as not everyone was in agreement; but it was clear that some heads of science were thoroughly convinced. J.J Thompson was noted to add that he was “confident that the Einstein theory must now be reasoned with, and that our conceptions of the universe must be fundamentally altered.” At that point, the respected astronomer Sir Oliver Lodge, walked out of the meeting.

 To the press, bending of light by gravitation, upstaging Newton, was news indeed. The 7th November 1919 headlines of The Times read REVOLUTION IN SCIENCE. The worlds press then go on the bandwagon and Einstein became a world celebrity. The year following, 1920, may be regarded as the year of ‘Einstein hysteria’, in which the essence of General Relativity and widely distorted and absurd versions about it, sprang up all over the place to heated debate, socio-didactic slang and satire. Einstein became a household name. By the end of the year, the only people who disagreed with it were; the unfortunate ignorant, the philosophically challenged, jealous physicists and radical anti-Semitic political opponents.

Scientists were satisfied with a working theory. And although it is well noted that Einstein added a physical constant called ‘the cosmological constant’ to make his model fit with the then current understanding of the ‘static’ size on the known universe; when the American astronomer Edwin Hubble proved that the existing universe was larger than the Milky Way Galaxy, extended to millions of galaxies beyond, and all of which were accelerating away in an expanding universe; Einstein relented in having “made the greatest mistake in my life”. Had he been less cautious, and not included his fiddle-factor, his model would have predicted Hubble’s discovery. Apologia aside, the Big Bang cosmological model, be it expanding or contracting, adjusted with new cosmological constants of varying polarity, still remains rooted in General Relativity.

 A succinct summary of Einstein’s achievements was penned by the Salk Institute biologist and science author J. Bronowski in 1973 with “In a lifetime, Einstein joined light in time, and time to space; energy to matter, matter to space, and space to gravitation”. What a wonderful legacy to share with the world.

E. Rutherford, F.W. Aston, Prout, J.J. Thompson, L. Meitner, A. Einstein
transmutation, atomic-chemistry, nitrogen into an isotope of oxygen, proton,
mass-spectrometer, whole number rule, mass defect, Packing-Fractions
binding energy, energy-mass equivalence, fusion to the left of iron, fission to the right, by-product of supernova


Using radium as a source for alpha particles, Ernest Rutherford in 1919 irradiated the gas nitrogen and discovered that hydrogen had been formed. Nitrogen is changed to hydrogen! Sensationalised in the press as ‘splitting the atom’; it was in fact more a transmutation than a split; the first recorded artificial transmutation of an element. What had actually occurred, and in terms of the new atomic-chemistry that was to follow; when an alpha particle, of atomic weight 4, manages to overcome the repulsive forces within the nucleus of nitrogen, of atomic weight 14, the collision transmuting nitrogen into an isotope of oxygen, of atomic weight 17, with the release of a hydrogen nucleus, of atomic weight 1. 

N-14 + He-4
O-17 + H-1
14 + 4
17 + 1

The hydrogen nucleus of atomic weight 1, with a single +ve charge, that was released by the nuclear reaction, as nucleic process would be called, was named a proton by Rutherford in 1920.

Francis William Aston returned to the Cavendish laboratory in 1919 with an idea of how to measure the mass of individual isotopes, in response to a question put to him by J.J. Thompson, for whom he was assistant, about the ratio of the masses of the isotopes of neon-20 +ne-22. His work for J.J., started in 1910, had been interrupted by the intervention of the First World War, during which time he had been working on improving doping for air-frames at the Royal Aircraft Establishment, Farnborough. By the end of 1919, Aston had improvised the first mass-spectrometer, initially limited to ionised gasses, and had begun to produce data on the mass of gaseous isotopes, relative to the mass of hydrogen-1, by measurements on scintillation screens and later on photographic paper. By 1920 he began improvements to his instruments, to include liquids and solids, and his results began impacting on the scientific community; and began giving credence to the Rutherford-Bohr atom. Some of these early results were in slight error, the atomic mass of helium being set too high, and would impact as blind allies of research for early investigations for fissionable materials, carried out by Leo Szilard and others, who were trying to make the first atomic bomb. The error would be corrected by 1935, as with better instrumentation, Aston resurveyed the elements between 1927 and 1935. Aston is credited, over around 20 years of research and development, of having identified some 212 of the [then known] 281 (75.4%) naturally occurring isotopes of the elements. Having previously determined the isotopic abundance ratios of neon, of atomic mass 20.2, by an arduous process of gaseous diffusion; Aston now presented the isotopic ratio of ne-20 +ne-22 from his mass-spectrometer data, to be 9 to 1 respectively, this satisfied J.J.

 Aston championed the work of Prout (1815) who had hypothesised the whole number rule; that atomic weights of the elements (now with their isotopes) would be whole numbers of the atomic weight of hydrogen. Aston was in an ideal position to do so, as his mass-spectrometer was now filling up the tables with unhithertofore accurate measures of atomic weight. Where at first the atomic weight of hydrogen was enumerated as 1, a new standard of weights was established, using the atomic weight of the isotope oxygen-16 as 16.00000; (All to be changed again, later to Carbon-12 as 12.00000). Notwithstanding these technical adjustments; the whole number rule still applies for thoughtful investigation. Aston then catalogued a mass defect that applied across the range of elements; best illustrated with the atomic weights of hydrogen and helium: H = 1.008; and He = 4.002; He = 4 x H nucleons, should be 4.032. Now 4.032 – 4,002 = 0.030 which is the mass defect for helium. That 0.79% of the expected mass is missing, somehow tla05_Packing_Fraction_02 needs accounting. Aston attributed this missing mass to energy needed to hold the helium nucleus together, what today is termed the binding energy, and used Einstein’s energy-mass equivalence formula, e=mc2, to account for it. In order to more easily visualise the mass defect across the whole range of elements, Aston devised a clever graph of Packing-Fractions to show it. The table that the physicist Lise Meitner would hold in her head in 1938. His formula takes the mass defect divided by the elements atomic mass x 10,000, and plots the results against rising atomic mass.

 To Aston, the plot is a measure of the stability of the elements, with the lowest, iron (5626Fe), being the most stable; and to the extremes, hydrogen (11H) to the left and uranium (23592U) to the right, having the most bound up, or releasable, energy; a quick account of the energy needed, or released, to transmute one element into another. To us today, it shows the elements of nuclear fusion to the left of iron, and the elements of nuclear fission to the right.

For the astronomer; a large star starts from the left by fusing hydrogen into more massive elements, that it then starts to fuse for the next stage, in steps, and so on, may-be missing a few steps, as the steps are usually in multiples of the helium nucleon, until it arrives at iron; where fusion stops. But because of serendipities in mass needed to form stars in the first place, the iron implodes under the high density conditions prevailing into neutrinos, and other things, in supernovae; the shock from which most all the other elements to the right of iron are now synthesised, and then scattered, together with all the left-over detritus of the elements previously synthesised to the left of iron, to the interstellar medium to merge into new-generation star systems of which sol-earth is an example. We find, and can then play with, the elements to the right of iron; and fission these in our nuclear toys; reactors and atomic bombs. Of course, we also choose to adorn ourselves with the confusion of gold; another, but non-radioactive, to the right of iron, by-product of supernova. Life itself, being a by-product of mostly the elements to the left of iron, and iron itself.

W. Heisenberg, M. Born, N. Bohr, L. de Broglie, M. Planck, A. Einstein, E. Schrödinger, P. Dirac, S. Bose,
C. Payne-Gaposhkin, E.O. Lawrence, M.S. Livingston, R. Wideröe
matrix mechanics, wave-particle theory, quantum mechanics, quantised momentum p, quantum probability, Schrödinger’s Cat, Bose-Einstein statistics,
stars…mostly of hydrogen and helium, particle accelerator, cyclotron


In the period 1924 to 25 theoretical physics was to experience a quantum leap of its own with the structuring of mathematical tools of such staggering diversity and imagination that the exotic would now appear mundane. The German theoreticians Werner Heisenberg and Max Born would develop matrix mechanics, stimulated by Niels Bohr. The French theoretician Louis de Broglie would contribute to wave-particle theory, and together with other accomplishments; using the ideas from quantum mechanics proposed by Planck and Einstein, with wave frequency f, Planks constant h, energy E, and momentum in the previous form p = E/c; derived quantised momentum p, which reduced to p = hf/c; and where c/f = λ (lambda) the wavelength, became = h. The Austrian (and later Irish) physicist Erwin Schrödinger would further develop wave-mechanics. The English mathematician Paul Dirac would prove that the treatments of Heisenberg, Born and Schrödinger were all in fact different expressions of the same thing; which much upset the esoteric Schrödinger; who would later involve Einstein in deliberations of quantum probability with the famous Schrödinger’s Cat, dead and alive, superposition of states paradox. Einstein would support the statistical probability mathematics of the Indian physicist Satyenda Bose, and work together with him to develop a branch of quantum physics called the Bose-Einstein statistics. Much of the early 21st Century theoretical physics is based on these earlier mathematical foundations.

 In around 1925 Cecilia Payne-Gaposhkin, an assistant at the Harvard College Observatory, determined that stars were composed mostly of hydrogen and helium, and not terrestrial types of matter, as was then thought to be the case. Her assessment challenged the male dominated community of science of her era, and took a while to sink in; but she correctly gave her slighted sisters and the stars, fuel with which to brightly shine.

1926 – J. Robert Openheimer

On the 2nd January 1931 Ernest Orlando Lawrence an American experimental physicist and his assistant M Stanley Livingston, using Lawrence’s development of an idea borrowed from a Norwegian engineer Rolf Wideröe that was effectively a prototype for a linear particle accelerator, that Lawrence had cleverly compacted into a 4.5 inch circular particle accelerator, operating between the jaws of a huge electromagnet, accelerated protons to 80,000 volts. [Quick note on principle of operation] It was the dawn of particle accelerators, artificially induced and controlled spears of energy, that would be needed to investigate the constituents of the atom. Lawrence and Livingston had brought the first cyclotron on-line.

Down BANG Up
J. Chadwick, E. Rutherford, I. & F. Joliot-Curie, W. Bothe, H. Becker, H.C. Webster, L. Szilard
H. Bethe
Discovery of the neutron, 7th and 17th February 1932, envisage the reality of the atomic bomb, 12th September 1933
aluminium, isotope of phosphorous, first chemical proof of the ‘transmutation’ of the elements, 15th January 1934


According to the theoretical physicist Hans Bethe, the history of nuclear physics only began in 1932 after Chadwick’s discovery. After reading a report by the Joliot-Curies about an experiment stated to have been conducted by bombardment with gamma rays, and discussing the results with Rutherford, who replied “I don’t believe it”, James Chadwick agreed with Rutherford, that for the results obtained, the bombarding rays could not have been gammas, but were something else entirely. Chadwick had an idea what they were, and set-up a series of experiments conducted at the Cavendish laboratory, Cambridge, between the 7th and 17th February 1932, to find them. When he had done, he had found that long elusive particle that Rutherford had speculated about back in his 1920 Bakeran Lecture, that massive particle with no charge, that left no trace in a cloud chamber because of it, ignorant to magnetic fields, that at the experiments intensity travelled through 40 cm of air, that whizzed through 2 cm of lead, that was the nuclear ‘hammer’ of physics that Hans Bethe was to later wax-lyric about; the explanation for an isotope, as heavy as a proton, the neutron. Chadwick credited Walther Bothe, Herbert Becker, H.C. Webster and the Joliot-Curies for their help and insights leading to his discovery.

 1933 Leo Szilard – The loose neutron of 20th Century nuclear science.  One is at first tempted to compare Szilard to the near mass-less neutrino that escapes through everything, on that shattering and creatively violent moment that a large mass star shines the brightest, in a type II supernovae explosion that releases the neutrino, that then goes on to penetrate near half the universe, unhindered, passing many mysteries along the way, before being captured in the twilight maze of an atomic nucleus, to expire in a spray of multidimensional exotic entities. On second thoughts, Szilard, whose character still appears unhindered and whom would have undoubtedly enjoyed the mysteries, is more related to that chain reaction, propagated by neutrons, the particle that he himself had wished for, that changed the world; the world that, singlehandedly, he had set out to save. Understanding Szilard’s character is not the object lesson here, others have made better note of that, but it is the knock-on effect that this Hungarian physicist started, that puts him in a category all of his own, as the master shaker of the technological world; with no less tangential a might than Genghis Kahn or Alexander the Great. Leo Szilard hastened the coming of the atomic age, was the first to envisage the reality of the atomic bomb on Tuesday, 12th September 1933, patented the process then gave it away to the British Admiralty, set about to insure its creation, and succeeded. World atomic power was a by-product.

 At the Radium Institute in Paris, Irêne and Frédéric Joliot-Curie, the inseparable pair of radio-chemists, Irêne being the daughter of the famous Marie Curie, and hence conferring the famous name to the pair who become affectionately known to the scientific community as the Joliot-Curies; in early January 1934, conduct an experiment that earns them a Nobel prize for chemistry. They radiate aluminium with alpha particles, and detect a ‘daughter’ element with a 3 minute half-life, which they chemically isolate and identify as a radioactive isotope of phosphorous. Their report published on the 15th January, provided the first chemical proof of the ‘transmutation’ of the elements by nuclear bombardment; the alchemists dream realised.

Enrico Fermi, O. Corbino, E. Sergè, F. Rosetti, E. Amaldi
M. Born, W. Pauli, W. Heisenberg, P. Jordan, P. Ehrenfest, O. Stern, L. Meitner, D. Debye
nick-named him the ‘Pope’, Professor…University of Rome, ‘Group of Rome’,
Rome’s physics institute, The laboratory, Saritià Pubblica – Health Department
beta decay, new type of force, ‘weak interaction’


Enrico Fermi skipped the part of the young child, but was a progeny none the less. Following the trauma of his brothers death, he started the first half of his early education in self taught study at the age of 14; and the other half unusually supplied by an engineer and other attentive family members. He acquired a skill for complex mathematics and a one-track penchant for physics. At the University of Pisa, what he wrote in his scholarship entrance exam, in other circumstances, would have equated sufficient for a doctorial thesis. He concluded his stay there by teaching his teachers. One of his strengths was General Relativity. An odd moment in career development occurred in 1923, when on fellowship to Göttingen, Germany, to study under Max Born; where he met Wolfgang Pauli, Werner Heisenberg and theoretician Pascal Jordan, among others, he was ignored and no spark of enthusiasm or insights resulted; his tasks were ordinary. A following brief fellowship to Leiden however, under Paul Ehrenfest, had him sparkling. From later collected descriptions; Fermi appears as a no-nonsense character with a touch of humour; but to the job in hand, straight to the point, the facts, nothing foggy; his equipment toys of purpose, he was the quintessential, and probably the first, ‘hands-on’ quantum engineer. His Italian colleagues fondly nick-named him the ‘Pope’. Fermi became Professor of theoretical physics at the University of Rome.

 The director of Rome’s physics institute, Orso Corbino, together with Fermi, wishing to bring Italian physics out of the doldrums and intent to build an institute of world standing, thought they should investigate the atomic nucleus. So they began to train and collect talented physicists and necessary equipment for a laboratory in Rome. The team of Rome would eventually include; Emlio Sergè sent to Amsterdam, then trained with Otto Stern in Hamburg; Franco Rosetti sent to Caltech, then to train with physicist Lise Meitner at the KWI in Germany and Edoardo Amaldi who trained with physical chemist Deter Debye in Lipzig. They assembled a cloud-chamber, a radium source and had KWI technical training in temperamental Geiger counters. The laboratory was set up in Rome’s Saritià Pubblica – Health Department – of the institute. 

In that period Fermi completed a definitive work on beta decay, a theoretical treatment of the high energy expulsion of electrons from a decaying nucleus. He introduced a new type of force, the ‘weak interaction’, that acted at inter-nucleic distances.

E. Fermi, O. Corbino, E. Sergè, F. Rosetti, E. Amaldi, O. D’Agostino
Transmutation of elements


To start the laboratory, Fermi’s next project was to use, he insisted, neutrons to irradiate all the known elements; to determine if they transmuted under nuclear bombardment. He knowingly went into competition with the Joliot-Curies to enhance the reputation of the Italian institution and was also determined that his team would make new discoveries themselves. Starting first with the light elements of the periodic table, and methodically working upwards in atomic number, he was on his way. He reported a 12 minute half life for aluminium on 25th March 1934, different from the Joliot-Curies earlier discovery, and continued up the table.

 Around mid April 1934 the Rome group had arrived at Uranium. They were beginning to return some results and building radio-chemistry rules in the process; so added a radio-chemist trained at the Rue Pierre Curie in Paris, Oscar D’Agostino, to the team.

The Rome group reported that light elements generally transmuted to lighter elements by either ejecting a proton (p) or an alpha particle (42H = 2p + 2n). 

*Add neutron to Phosphorous 3015P + n = 3115P
*Eject proton get Silicone 3115P - p = 3014Si
*Add neutron to Vanadium 4623V + n = 4723V
*Eject alpha get Scandium 4723V - 42H = 4321Sc

 A heavier nucleus has more protons and thus a heavier charge. With more neutrons, the binding energy is also larger. The heavier nucleus is more difficult to get out-of because of these forces. So what the Rome group report was as the nucleus got heavier, it captured a neutron and radiates gamma photons; thus with no charged particle emitted, it becomes a heavier isotope. 

*Add neutron to Tellurium

10452Te + n = 10552Te + energy

 But they also reported that something else would happen. After a delay, it would emit a –ve beta, which is a positron. And to get a positron they considered a neutron changed to an proton with the release of a +e, transmuting the element into a heavier element. 

*Eject +e to get Iodine

10552Te - +e = 10553I

 As they were observing delayed –ve beta decay with uranium, Fermi thought, by the same process, that they were transmuting to a heavier element than uranium, as yet undiscovered. It would be the first transmutation into an artificial man made element. This was new territory. 

*23892Ur  + n *23993X + +e

* Examples of transitions only, not real reactions

 Interesting, but as yet without proof, the Rome group reported by 10th May 1934, that they had found activities induced in uranium, with half-lives of 1 and 13 minutes + others of longer durations as yet to be specified.

Looking at this induced series further, it was found that they were all beta emitters and D’Agostino had managed to separate the 13 minute activity with a manganese carrier. 

With the debate that it could be heavier than uranium, D’Agostino set out to try to prove that is was not lighter than uranium, by checking with the known heavy elements. The chemistry proved it was not Lead-82, Bismuth- 83, it excluded Radon-86, Francium-87, Radium-88, Actinium-89, and Thorium-90.

On the other hand, Polonium-85 was un-checked and [Astatine]-85 was (then) unknown. 

At that point, the Rome group were still polarised in thought towards a heavier element than uranium-92, x-93, as the source of the 13 minute activity. They reported their screening activities and made cautions thoughts on x-93 in June 1934.

Then they had a serious embarrassment when their director Corbino announced, at terms end, over-excited by the presence of the King of Italy, that they had found a new element. It go into the press and went international. But it was the summer holidays; so the embarrassment passed, nearly.

Fermi sailed to the South Americas on a lecture tour, leaving it all behind.


Plot of atomic isotopes colored by half life. Isotopes and half-life eo.svg, image file; by BenRG, 26 September 2009; Public domain, Wikimedia Commons

L. Szilard, Mem. M. Curie, A. Einstein
Patent, death, Eulogy


Independence day USA 4th July 1934: Leo Szilard patents the atom bomb on the same day that Mem. Marie Curie dies. Albert Einstein presents the most moving eulogy “of all celebrated beings, the only one whom fame has not corrupted.” (R. Rhodes – pg. 215)

E. Fermi, E. Sergè, F. Rosetti, E. Amaldi, O. D’Agostino, B. Pontecorvo
Hans Bethe
theoretical model (atom) was faulty, neutron capture, Aluminium near 3 minute activity
wooden-marble table problem, discovery of slow neutrons


With Fermi away, Emlio Sergè and Edoardo Amaldi visited the Cambridge laboratory, in England, with two problems to discuss. The first was neutron capture; where current theory on the ball nucleus suggested that neutrons whizzing through the nucleus, had about 10-21 seconds to get through. The Rome team found that by experiment they got gamma emissions after 10-16 seconds: -21 + 16 = -5: 100,000 times too long. Thus they supposed the theoretical model was faulty. The second problem was that they wanted proof-positive of neutron capture with a gamma emission. Nothing new on the first problem transpired (that would come later from Bohr); But on the second problem; the Cambridge team found the required neutron capture, in sodium, while they were there.

 On their return to Rome, with Oscar D’Agostino’s help, they repeat the sodium proof, and then find a second case with Aluminium, with a half-life of almost 3 minutes. This was around August 1934.

A returning Fermi stopped in London at an international physics conference, and having had news from Rome, presented that of the 60 elements radiated by the group of Rome, they had induced activities in 40 of them; placed the radiation capture problem to the forum; cited the Cavendish team sodium results; and then reported Sergé’s and Amaldi’s Aluminium near 3 minute activity results.

 Then there was trouble. Despite great efforts, Amaldi could not repeat the Aluminium near 3 minute results. Fermi got upset and dressed the team down heavily.

After Fermi’s chastisement, Bruno Pontecorvo joined the Group of Rome at the time when they were planning to standardise the radiation sources to silver, with a half-life of 2.3 minutes, which should give their results some base-line consistency. But they discovered to their astonishment that different activation tables around the lab, caused different radiative intensities from their silver sources. A certain wooden table near a spectroscope caused the highest radiation when compared to a source on a marble table in the same room.

 They decided to tackle the problem, but lost sight of their investigative faculties in favour of engineering solutions by applying shielding techniques to solve the problem. Starting on the 18th October they began measurements within and without lead shielding, to arrive at the 22nd October 1934 with the bazaar idea to test placing a lead shield between the source and the target. Truly fish out of water, from a historical perspective, and by distorted metaphor; no less than divine intervention hindered fledglings in their work to attend to student examinations that halted their work and brought the ‘Pope’ into the picture. Fermi now had to run the ‘lead’ experiment on that day. The master dithered with subliminal excuses warring in his head, and placed instead a paraffin shield in place of lead. The system roared into activity. The late morning saw pilgrimage to the experiment with noises of “Fantastic! Incredible! Black Magic!” Fermi went home to lunch.

 Fermi came back after a solitary lunch with probable answers and a few testable theories.

 The hydrogen in the paraffin and of the wooden tables, slowed down the neutrons. That took care of the wooden-marble table problem.

The slowed neutrons had more time to be captured by the nucleus. That took care of the sources.

How to test for hydrogen? Water! Corbino’s goldfish pond at the back of the building would do. An entourage of equipment irradiated the goldfish; and it worked as well in water as it did with paraffin.

Now for the effects of slow neutrons. With the paraffin shield; silicon(14), phosphorous(15), zinc(30) – no appreciable effect; aluminium(13), copper(29), iodine(53) – were all activated.

They tried radon without beryllium, as a source, to insure that neutrons and not gamma rays, were being slowed – It was the neutrons.

They used oxygen in place of paraffin as shield – a decrease in intensity; oxygen slowed neutrons less than hydrogen.

 Sergè typed “Influence of hydrogenous substances on the radioactivity produced by neutrons – I” at Amaldi’s house after dinner. Fermi dictated; Rossetti, Amaldi and Pontecorvo shouted. After they left, a house-maid timidly asked if they were all drunk. Yes – with excitement. The paper ended with a note on the just short of 3 minute activity of aluminium; is was enhanced by slow neutrons; but diminutive with fast neutrons and here overwhelmed by other induced activities.

 A codicil to understanding was that Sergè and Amaldi had not failed in their work months before, but had used a marble table, with a null result for the <3 minute activity of aluminium.

The groups next task, was to start all over again, now using slow neutrons, to determine any new isotopes and decay products.

 The notion of slow neutrons had arrived. Hans Bethe later commented that they “might never have been discovered if Italy were not rich in marble” prompted from the observation that in America, most lab-tables were wooden. An amusing point; but “delayed” rather than “never” would be more to the truth. Slow or thermal neutrons, would become the activators for ‘power’ and ‘breeder’ reactors; and fast neutrons, the avatars for bombs.


All elements of atomic number > 92, i.e. 93 to 118 (shown in green above), are man-made elements; all of which are unstable - they immediately begin to spontaneously decay.
Find Page update (2017) to recently named elements, atomic number 112 to 118 (above)

A. von Grosse, I. Noddack, E. Fermi
L. Woods, E. Teller, Joliot-Curies, O. Hann
Criticism … the Group of Rome, element 93


Later in 1934, the criticism of the work of the Group of Rome started coming in.

 In a paper by Aristide von Grosse it was argued that the group had created protactinium(91) and not a transuranic X(93) as claimed. The Group of Rome took it as a challenge to push ahead.

The Completion Backwards Principle exists largley through a song (The Tubes) 1981; so in its sentiment, this part of the story can be told backwards. 

Leona Woods wrote, answering a question; that Ida Noddack, a German chemist and co-discoverer of rhenium(75)[1925], was ahead of her time; and that Bohr’s liquid-drop model of the nucleus (1937) had not yet been formulated to allow informed estimates about the size and dynamics of the atomic nucleus.

This would mean that Edward Teller’s version that “Fermi performed the calculations – and found the probability was extraordinarily low … so he forgot about it.” Was a good assessment; where Fermi had told Teller, Sergè and Woods that he had done the calculations. The fact is that Fermi’s model was wrong in September 1934; he got wrong answers, but did not know it.

Ida Noddack was ahead of her time when she wrote “it is conceivable that the nucleus brakes up into several large fragments, which would of course be isotopes of known elements but would not be neighbours [i.e. close to uranium in atomic number].” She had reacted with “Fermi therefore ought to have compared his new radioelement with all known elements,” continuing her criticism with “not clear why he chose to stop at lead[82]” referring to “his new beta emitter” about which Fermi stated was not protactinium(91), and nothing down the range of elements to lead(82). Noddack, who was a good chemist, pointed out that any number of elements could be precipitated out of uranium nitrate with a manganese carrier. His “Method of proof” was “not valid” was where she had begun. 

Appearing in The Journal of Applied Chemistry in September 1934; Ida Noddack’s “On element 93” criticised Fermi’s June paper “Probable production of elements of atomic number higher than 92.” Noddack had hit hard with “the reports found in the newspaper” when reflecting on Corbino’s ill-timed announcement. But the message had got through to the intended, if only, recipients; Fermi, and as Emlio Sergè reported, by messages he sent to the Joliot-Curies in France, and to Otto Hann at the KWI in Germany. Its publication in a specialist journal, made low its message and readership. 

Summing up their work in a paper on 15 February 1935, the Group of Rome were still of the opinion that the activities they had induced in uranium; a 15-second;13-minute and 100-minute half-life products; i.e. a series where each was the product of the next stage; were of Ur(92); X(93) and Y(94) of atomic weight 239. 

Given the hindsight of time; one is reminded here that some, but not all, of these assumptions and results made here by the Group of Rome, for a number of different reasons, contain error and errors of interpretation, that did not come to light till later. But research, like a detective story, has its fevers and its clues. The acuity of Hann-Strasmann in their paper (See below), brought a cautionary reminder from Fermi, in 1939, about reviewing the data for reaction products of uranium.

H. Beth, N. Bohr, Group of Rome, E. Fermi,
O. Hann, F. Strasmann, L. Meitner, O. Frisch, W.A. Arnold, H. Anderson, L. Rosenfield, Joliot-Curies,
F. Houtermans, R. Atkinson, E. Rutherford, G. Gamov, H. Bethe
“neutron capture and nuclear construction”, change to the model of the nucleus, liquid drop model,
splitting of the uranium atom, “an extensive burst”, fission,
thermonuclear reactions, proton-proton or p-p chain, carbon cycle, CNO - Carbon-Oxygen-Nitrogen cycle


After displaying some obvious surprising mental cognations while being given a report on some calculations by Hans Beth on the low probability of neutron capture by the nucleus; Niels Bohr summarised his cogitations in a lecture at the Danish Academy on 7th January 1936. Bohr was pressing for theoretical improvements with his “neutron capture and nuclear construction” in which he outlined a change to the model of the nucleus. Dispelling previous suppositions that neutrons sailed through the nucleus; instead of a ball of mixed nucleons, he proposed now a distinct collection of nucleons, a mixture of protons and neutrons closely packed together.

Bohr surmised that neutrons could not pass through this nucleus, that they are captured by the strong force and agitate the nucleons inside. Nothing can escape as the strong force holds all the nucleons together. The excited nucleus now ejects a gamma ray photon to ‘cool-off’, as the nucleus returns to some level of equilibrium; and the element would gain a unit of mass, becoming just another isotope. All confirmed by the Group of Rome’s recent experiments.

The size of the atoms nucleus had now gone from small to tiny. The comparative dimensions of the atom, with respect to ‘empty space’ and the size of the nucleus, still remains by any standards quite staggering; where a calculation that magnifies the construct, reveals a model equivalent to a grain of sand sitting in the middle of the Albert Hall.

It turns out however that Fermi and his Group of Rome team were ahead of the game in 1934, but were misled because they lacked this model for the atomic nucleus, and thus came to erroneous conclusions.

Niels Bohr, drawing reference to his doctorial theses on surface tension in fluids, in 1937 proposes in a paper that the nucleus of an atom would behave like a liquid drop. He suggests that the strong nuclear force that binds the nucleus together, acting similarly to surface tension, would be opposed by the +ve charge within the nucleus, which would tend to force it apart. In this state, the nucleus would oscillate like a wobbling liquid drop, if struck by an incoming object. This idea the liquid drop model would become, a year later, central to the preliminary explanation for the splitting of the atom.

In 1938 Enrico Fermi received the Nobel prize for his radio-active isotopic and slow neutron discoveries. He used the funds to narrowly escape Italy’s involvement in WW2; and set up with his family a new life in the U.S.A. He contributed hugely to the development of atomic physics in the U.S.


On the 21st December 1938 the German radio-chemists Otto Hann and Fritz Strasmann discover an error in previous chemical analysis of ‘daughter’ products of nuclear reactions previously conducted in their laboratory at the Kaiser Wilhelm Institute for Chemistry in Germany, and they confirm the ‘daughter’ to be an isotope of barium, not radium as many had previously thought. They remain sceptical, as this appears to be a ‘daughter’ of uranium; an unusually large fragment of the mass of a uranium atom, almost half; a ‘daughter’ of unexpected size, and also thus far unreported by radio-chemists. They communicate with the German physicist Lise Meitner, now in war exile in Sweden, wishing her considered advice in explanation. 

Meitner, in a holiday discussion with her nephew the German physicist Otto Frisch, on the 24th December (Christmas eve) 1938; conceives an unstable dum-bell shape for the nucleus of uranium, based on Bohr’s idea of the nucleus acting like a water droplet, which would split into two large pieces on absorption of a slow neutron. Meitner and Frisch conclude that it is the charge of the +ve protons, acting in repulsion, in the dum-bell shape, that assists in driving the unstable nucleus apart on incidence with the low energy neutron. This is evidence of splitting of the uranium atom! Using data from Aston’s Packing-Fractions that Meitner had memorised, they calculate that the energy released per nucleon, to be of the order of 200 Meg-eV (electron volts); this is a huge amount of energy. Frisch later calculates that this release from one atom alone, would make a small grain of sand jump. Meitner shortly communicates to Hann her congratulations for his and Strasmann‘s important “an extensive burst” discovery. 

On his return to Copenhagen, Otto Frisch sets up an experiment for evidence of splitting of the uranium atom with slow neutrons. On the 13th, and repeated on 14th January 1939, Frisch succeeds. A visiting American student biologist William A Arnold, observing the experiment with him on the 14th, inspires Frisch to name the process of splitting the atom, by a biological term, fission. Frisch would contact Meitner to confirm this result and they would both present reports, posted on the 16th, using the term fission.

At Paupin Hall, Colombia University in New York, Herbert Anderson is the first United States physicist to split the uranium atom on 25th January 1939, having been briefed on the Hann-Strasmann experiment before-hand, by Niels Bohr himself; but unaware of Fisch’s previous success. The news through the grapevine, had been leaked accidentally to the Belgian theoretician Leon Rosenfield by a boat travelling Niels Bohr on his way to a US physics conference in Washington. The grape vine took the news east, and Bohr’s report at the conference on the 26th took it west; whenst it ignited the U.S., Leo Szilard and a worried Fermi into bomb making. The ‘Pope’ had done sufficient noble work to hold laureate, and needn’t have worried; but he shortly appended a note to the Rome paper on transmutations cautioning that the results should be reviewed for reaction products of uranium. In France, the Joliot-Curies chagrined to have so nearly missed the opportunity, having had all the same reports from Europe; split the uranium atom on 26th January 1939.

In Göttingen Germany, in the summer of 1927, physicist Fritz Houtermans and visiting British astronomer Robert Atkinson speculated about the energy production of the stars while on a walking tour. British astronomer Arthur Eddington had recently indicated from observations that the sun and stars burn at 10’s of millions of degrees and last lifetimes of billions of years; a prodigious use of energies that was unexplained. Could the nuclear transformations that Rutherford was demonstrating be the source of such power? They worked out a basic theory, that at the high temperatures and pressures in the core of stars that nucleons would have sufficient kinetic energy to penetrate the electronic barriers of a nucleus, an release binding energy; sufficient to power the star. A theory correct in principal but inaccurate in detail. Houtermans and Atkinson would later work with the Russian theoretician George Gamov to correct the detail and further the aspects of the theory; and named such processes thermonuclear reactions, on accord of the high temperatures at which they operate. The German theoretical physicist Hans Bethe in 1939 added to the theoretical model for nuclear fusion; the nuclear combination of lighter elements to form heavier ones, when he unravelled the carbon cycle, termed CNO for short or Carbon-Oxygen-Nitrogen cycle at length; a secondary high temperature fusion reaction of hydrogen into helium, a process step that powers the stars. Bethe was awarded a Nobel for this effort.

See section: Sun – Sol for details of the p-p and CNO reactions.

Enrico Fermi the ‘Pope’, L. Szilard, H. Anderson, B. Feld, G. Weil, W. Zinn, J. Marshall, A. Wathenberg, S. Allison, F. Spedding
‘nuclear pile’, ‘exponential’, reproduction factor, chain reaction
experimental reactor, liquid moderated reactor, carbon moderated ‘exponential’ reactor, carbon moderated nuclear reactor
Schermerhorn Hall, Columbia University, New York; doubles squash court, Stagg Field, University of Chicago


In 1939 Enrico Fermi set about to prove that nuclear chain reactions were possible. To do this, he had to build experimental reactors from which to deduce the fundamental parameters of not only the materials necessary, but of how to control such systems so that they would not blow up in the process. Later he was tasked by The Manhattan Engineer District (MED) project to prove methods for the high volume production of plutonium, a man-made element, produced by the nuclear bombardment of uranium, and for which a controlled nuclear reactor was necessary. Fermi, the first quantum engineer, would make the first series of historic nuclear reactors to test this technology, the by-product of which would be the nuclear arms industry of the USA and Britain; and the nuclear power industry of the western democratic world. 

An industry develops its own nomenclature. The word ‘pile’, used in ‘nuclear pile’, was derived from Fermi’s struggled translation, into linguistic American, of the word ‘heap’. 

The term ‘exponential’ refers to an exponential term in a scaling factor equation that would upsize the model to a theoretically full blown critical reactor. Activity reproduction factor k:  not critical < 1.00000 > critical.

  1. Columbia University, New York; Fermi with Leo Szilard and Herbert Anderson build one of the first experimental liquid moderated reactors in the USA. It is not for criticality; but is used to test the feasibility of a chain reaction. In a round water tank using 52 x 2-inch dia x 2-ft long steel cans containing uranium oxide. It was first run in June 1939 to give a result of 1.2 neutrons per thermal neutron. It proved for the first time in the U.S.A. that chain reactions were just about possible.

  2. Columbia University, Schermerhorn Hall, New York; Fermi, Herbert Anderson, Bernard Feld, George Weil and Walter Zinn, with Leo Szilard organising the supply of high purity carbon; build the first experimental pile, a carbon moderated ‘exponential’ reactor. A 9ft cube of carbon bricks packed with 288 x 8 inch square steel cans packed with uranium oxide. It achieved k=0.87 in September 1941.

  3. Columbia University, Schermerhorn Hall, New York; Fermi, Herbert Anderson, Bernard Feld, George Weil, Walter Zinn, John Marshall, and Albert Wathenberg, build the second experimental pile, a carbon moderated ‘exponential’ reactor. A 9ft cube of carbon bricks, all encased in a steel can, packed with 2000 x (4 inch ?) spheres of compressed uranium oxide. It achieved k=0.918 in April 1942.

  4. University of Chicago, Stagg Field, doubles squash court; Commissioned by the MED project and under Fermi’s supervision; Samuel Allison build an experimental pile, a carbon moderated ‘exponential’ reactor. A 7ft cube of higher purity carbon bricks than had been used at Columbia, and with uranium oxide. It achieved k=0.94 also in April 1942. Between May and August 1942, reconfigurations of the pile with different grades of materials achieved k=0.995 to k=1.04. That meant they had achieved a working model. Between 15 September and 14 November 1942, Herbert Anderson and Walter Zinn built 16 successive piles to qualify incoming carbon and uranium materials, some of which was rejected.

  5. University of Chicago, Stagg Field, doubles squash court; Fermi, Herbert Anderson, Walter Zinn, and their team as before; start building on 16th November; an experimental pile, the first carbon moderated nuclear reactor. A 25 ft long x 20 ft wide x 20 ft high, egg shaped ellipsoid of very high grade carbon blocks stacked to 57 layers; supported by a rough wooden frame. Controlled by 10 x 13 ft control rods of cadmium sheeting tacked to wooden rods. It contained a mixed charge of uranium metal and uranium oxide in cylindrical pseudo-spheres some 7 in high x 3.25 in diameter, called Frank “Spedding’s eggs” after a chemistry group leader who had manufactured them. 771,000 pounds (344 tons – 350 tonne) of graphite, 80,590 pounds (36 tons - 36.5 tonne) uranium oxide and 12,400 pounds (5.5 tons – 5.6 tonne) metallic U-238. On 2nd December 1942 at 03:48.5 pm Chicago, achieving k=1.0006; Fermi ran the pile critical for 4.5 minutes at a power of 0.5 Watts, before he shut it down. 42 people, including the risen ‘Pope’, Leo Szilard, and many eminent and upcoming scientists, had witnessed this historic moment. The beginning of the new atomic age.

W. Heisenberg, Plato, S. Glashow, A. Salam, S. Weinberg
1936 Bohr-Rutherford atom, the smallest unit of a chemical element,
the last atom, Standard Model


The German theoretician Werner Heisenberg in 1925 had been shocked that Plato (427-348 BC), one of the Greek Pythagoreans, had visualised such as an atom, in any geometric form; as it could not be seen, it was a mathematical abstraction; Heisenberg preferred abstractions. The 1936 Bohr-Rutherford atom was now however complete as the first working model of the atom. It was visualised as a cloud of light negative electrons surrounding a tiny nucleus composed of a balancing number of heavy positive charged protons, together with, in the main, a similar number of similarly heavy neutral neutrons. The Pythagorean idea that the atom was the smallest indivisible particle of matter allowed, seemed to have at last been described. But the atom was composed of supposedly fundamental particles, the electron, the proton and the neutron; and even these entities were now under siege by experimental discoveries and by the theoreticians, as being sub-components or having some sub-components of their own. The 1936 Bohr-Rutherford atom, although a helpful working construct, was the last atom of a past era.

  A conceptual illustration of the Bohr-Rutherford atom.
  Depicting the helium atom, with the nucleus (pink) and the conceived electron cloud (-ve) distribution (black); the outer extent of the active atom.
  The nucleus (upper right) illustrates helium-4; conceptually showing 2 x protons (+ve) and 2 x neutrons (electrically neutral). The scale to the order of 1 fm (a femtometer), or 100,000 thousand times smaller than the active extent of the atom itself; an extremely tiny volume containing the main mass of the atom. Dimensions that conjured the before mentioned comparison 'A grain of sand in the middle of the Albert Hall'.
  In reality the nucleus is itself a spherically symmetric probability distribution cloud containing the closely bound protons and neutrons. For higher order atomic mass atoms, this symmetry breaks down into more complex shapes.
  The black scale bar is one angstrom (10-10 m or 100 pm (picometers)) in length.

Helium atom QM.svg, Wikimedia Commons; Yzmo
(updates by Oleg Alexandrov, Bromskloss & Jorge Stolfi)


The last Atom; Helium atom - Wiki

Royal Albert Hall


Grain of Sand

Royal Albert Hall, London, UK
Image: IMG, The ATP Champions Tour, 2017.


Artist Vik Muniz drew the castle on paper, then scientist Marcelo Coehlo carved it onto the grain of sand using a focused Ion Beam.
Image from; featured on Bedtime Math at, by Laura Overdeck, Daily Math, Entertainment, Science and Nature, 18th November 2015.

In difference to historical precedent; the name ‘atom’ survives today, as the smallest unit of a chemical element. The behaviour of its electrons is quantised; and the affinity of charge of the electrons filling the outer quantum shell, leads to physical chemistry. Its behaviour is described by quantum electrodynamics. The atom is however divisible.

In brief; today the last atom is now defined in the Standard Model, a construct of many mathematicians and theoreticians and supported by the results of international experimental physicists, and credited to the work of Sheldon Glashow (1960); Abdus Salam and Steven Weinberg (1967). It supports 61 elementary particles, of which the last, the Higgs boson, in the mass region of around 125-126 Gig-eV, was identified at CERN in a series of experiments carried out through 2011 to 2012, to be declared existent with a statistical significance level of 5 sigma, on 4th July 2012.

In hierarchical classification of the Standard Model, the components of the last atom become:

The electron – A fermion class lepton
The proton – A hydron AND fermion class baryon
The neutron - A hydron AND fermion class baryon

F.W. Aston, A. Sachs, President F.D. Roosevelt, E. Wigner, L. Szilard, A. Einstein, Watson
...not use it exclusively in blowing up, 11th October 1941, commit … U.S.A. to an atomic bomb project, Einstein’s…letter


Following his resurvey of the atomic weights of the elements in 1935, in a lecture given by Francis William Aston in 1936, he was aware that once the means was found, atomic energy could be useful for mankind, but in a flush of typical dry British humour, ended his speech with the procaine comment: “… man will realise and control its almost infinite power. We cannot prevent him from doing so and can only hope that he will not use it exclusively in blowing up the next door neighbour.”
Aston died, age 68, on the 20th November 1945, having sad account of Hiroshima and Nagasaki. 

It is with assertive irony for history to record that on Wednesday, 11th October 1941, the last utterances of the economist Alexander Sachs to convince the President Franklin D. Roosevelt, his old friend, to commit the resources of the U.S.A. to an atomic bomb project, would have been a reading of this last paragraph of a transcript from Aston’s address, to which the president replied. 

“Alex,” said Roosevelt, quickly understanding, "What you are after is to see that the Nazies don’t blow us up.”

“Precisely,” Sachs said.

Roosevelt called Watson. “This requires attention,” he said to his aid.

 Rhodes, Richard © 1986; The Making of the Atomic Bomb; p.g. 324

 The letter to the President that Eugine Wigner and Leo Szilard had solicited from Albert Einstein some three months past on 16th July 1941, and who had signed the final draft later; had been outlined by Sachs, as had Leo Szilard’s covering letter, when he had started his verbal brief to the President. The letters went unread with the file to Watson.

  * - A play on the name of the Si-Fantasy novel Something Wicked This Way Comes, 1962, by Ray Bradbury

Down Fast Neutrons & X-Rays Up
Man-made Uncontrolled fast nuclear reactions on Planet Earth

nuclear-bomb_04_hiroshima +nagasaki_destroyed_August1945_composit_01
10 - The nuclear Destruction of Hiroshima and Nagasaki in Japan - 6th and 9th August 1945 respectivly.

  The 2nd & 3rd 'Atomic' (A) bombs, respectively, to be detonated on planet Earth. The first atomic devices to be used in warfare. These atomic devices were used in a conflict known as the Second World War (1939 to 1945). The belligerent Japan, which had initiated a conflict with the United States of America on Sunday, 7th December 1941 at 07:53 Hrs, with a surprise attack on Pearl Harbough, Hawaii, had been bombed in August 1945 by the U.S.A. with atomic devices; ostensibly to shorten the conflict. An ethical debate that later arose as to the method and desirability of uses of such weapons in this conflict; is noted here only as a matter of historical record. At this time; there is no other record, declared or investigated, of any other such atomic devices having been used in any world conflict since that time.

  There have been records of the use of atomic munitions in world conflict. This definition however applies to ‘depleted uranium-238’, a particularly heavy metal, used only as bullets (not nuclear explosives). It is a waste product of atomic bomb manufacture, having a low U-235 content (depleted). It would be the by-product of any enrichment process, gaseous, centrifugal or otherwise; seeking to increase the content of the isotope U-235, from a starting base of natural uranium. It is of particular note to have been the 10mm munitions of the flying Gatling gun, the ‘bathtub’ C-10 air-to-ground jet striker (anti-tank), of the U.S.A.F. As these pages have outlined, U-238 is a natural radioactive, with a half-life of some 4.5 billion years; is an alpha and gamma emitter in the main, but will begin to emit gamma’s as well, as its many ‘daughter’ products accumulate over time. It is recorded to have been used in U.S conflicts with Middle Eastern countries between the late 20th Century and the early 21st. Its use is inferred from doctors reporting from affected Middle Eastern countries where; incidents of patients having unusual radiation sickness and tissue damage, and many patients being particularly young children. Children are particularly venerable; playing on past battle fields; collecting unusually heavy shrapnel; and playing inside disabled military tanks, the inside of which is unknowingly contaminated with a coat of vaporised uranium munitions.
trx_10_Gilda-Crossroads Able, USA, Bikini,^onehundredyears^expeditions^Bikini^SIA2010-0974_large_990w_600h
10 - Gilda - Crossroads Able - Bikini Atoll, US Marshall Islands, Pacific Ocean
Image from
1st July 1946, 08:30 am, local time, over the lagoon of the Bikini Atoll, the US Marshall Islands. The atomic bomb 'Gilda', from the US test series Crossroads Able; the first post-WWII atomic bomb tests. The shot was named 'Gilda' after Rita Hayworth's character in an eponymous 1946 film; an air blast from around 520 feet (158 m) above a target fleet of old warships. The estimated 23-kiloton blast was very impressive, but a little bit off the target point, resulting in less test damage than was hopefully expected.

trx_20_The Bikini suit history_Time Inc_tobagojo@gmail.com_20160703_set-01_990w_564h
10 - And hence the birth of the now ubiquitous 'Bikini', on 5th July 1946
Photos (as noted) from TIME Inc. The Evolution of the Bikini.

nuclear-bomb_20_French nuclear test 1971 at the Mururoa atoll, French Polynesia. (AP Photo)_essai_nuclc3a9aire_franc3a7ais_990w
10 - The A Bomb
AP Photo: French nuclear test 1971 at the Mururoa atoll, French Polynesia.

nuclear-bomb_22_French nuclear test at the Mururoa atoll, French Polynesia. (Pierre J. - CC BY NC SA)_X990w
10 - A-Bomb
J Pierre - CC BY NC SA. French nuclear test 1971 at the Mururoa atoll, French Polynesia.
Horrendously beautiful.

10 - The H Bomb
Castle Bravo - 15 MegTon TNT equivalent - was the code name given to the first U.S. test of an expandable (power of device virtually adjustable at will) dry fuel thermonuclear hydrogen bomb (fusion) device - Bikini atoll Marshal Islands 1st March 1954
Man emulates the generating power of stars.

10 - Tzar Bomba – 57 Mega-tons TNT (equivalent) dry-fuel Fusion device. The largest nuclear device ever detonated (to date - April 2013).
30th October 1961 11:32 AM (Moscow Time) over the Novaya Zemlya archipelago in the Arctic Sea, at the Mityushikha Bay nuclear testing range (Sukhoy Nos Zone C, field D-2); USSR.

  Variously named the Tzar Bomba, Big Ivan, Project 7000, RDS-202, RD-220, RN-202, AN-602 (USSR); and JOE-111 (CIA, USA), among others; the device was a one-off scalable, triple stage fission-fusion-fission device; scaled down (by dispensing the final fall-out-dirty fission stage with dud lead tampers rather than fissionable U-238) from a theoretical maximum of 100 Mega-tons, to 50 Mega-tons (equivalent) for the test; and weighed an unwieldy 27 tonnes (59,500 lbs).
  Observers concede that it was a clever device design, as within the given time constraints (see later); it was made from an array of available smaller war-head modules, with the design focused on how to arrange the components so that they would all concatenatingly detonate; rather than a full-blown up-scale design that would have required considerable theoretical modeling, device re-tooling and time to accomplish. Using an estimated ~1.5 Mt of dirty fission to attain in excess of 50 Mt of fusion yield, Tzar Bomba has been deemed one of the cleanest power to fall-out ratio nuclear devices ever detonated; + the air blast contributing to less fall-out; dirty nevertheless.
  Dropped by parachute from an altitude of 10,500 meters (6.5 mi) to allow the propeller driven Tu-95V release plane, flown by Major Andrei Durnovtsev, sufficient time (3m:8s) to escape the blast from ~45 km (28 mi) away; the Tzar Bomba detonated at a barometric control height of 4,200 meters (2.6 mi); 4,000 meters above ground-zero.

  A grandstand political posturing exercise by the Premier, Chairman comrade Nikita Khrushchev of the USSR politburo, the Tzar Bomba was conceived as a demonstration of Soviet technical and scientific supremacy, during the nuclear arms-race of the Cold War period (late 50’s to early 60’s) between the USSR and the USA.
  However impractical a nuclear device for the Soviet military arsenal, because of size, weight, over-yield and the constraints of the slow delivery technology of the day, the Tzar Bomba demonstrated functional Soviet infrastructure systems, however reported as distorted , terrorized or over-stressed; to design, manufacture and demonstrate a working devise, in the remarkably short time frame of 16 weeks it took from Khrushchev’s initial demand, on the 10th July 1961, to a successful explosion in time for the Twenty Second Congress of the Communist Party of the Soviet Union, in November that year.
  With the advanced boastful warnings of Khrushchev, the US Joint Atomic Energy Intelligence Committee and the CIA had time to prepare and deploy an USAF KC-135 Stratotanker snooper aircraft to within about 45 km of Tzar Bomba’s ground-zero. The plane nearly got blown out of the sky by the blast, suffered heat damage to its paint; however the accumulated data from which flight, analyzed by the Foreign Weapons Evaluation Panel in the USA, headed by physicist Hans Bethe, concluded the 57Mt yield estimate; believed to be the most authoritatively accurate, without political clutter, and stated here as the accepted yield.
  As a demonstration of one of mankind’s most powerful nuclear detonations, Tzar Bomba was small in energy content when compared with natural Earth weather, volcanic or tectonic activities; but was nonetheless titanically spectacular and truly awesome as a man-made energy-release event.

  The near instant 8 km (5 mi) diameter fire-ball (image centre), prevented from touching the ground by reflective blast-shock, rose as a phempto-sun to an altitude of some 10.5 km (6.5 mi, 34,449 ft), polishing with its X-ray and thermal radiations some 256 sqkms (98.8 sqmiles) of the surface of Novaya Zemlya to the smoothness of a skating rink; and delivering a ground-zero overpressure of some 2.07 Meg Pascals (300 psi.). The ball is reputed to have been seen at 1,000 km (620 mi) from ground-zero.
  The vortices of cool air in-rushing to replace the rising hot-air column produced a mushroom-cloud that rose through the stratosphere, well into the mesosphere, to an altitude of some 64 km (39.8 mi, 209,974 ft) (image left); its base expanding to some 40 km (24.9 mi) in diameter, covering some 5,026 sqkms (1,940 sq miles) (image right).

  Three people are reported to have been killed in the Sukhoy Nos test range, at the village of Severny, when the building collapsed around them, some 55 km (34 mi) from ground-zero. The heat from the explosion could have caused third-degree burns at 100 km (62 mi); and permanent sight damage at 220km (137 mi). A test participant reported seeing the ignition-flash, through dark goggles, and felt the heat of the thermal pulse, at a distance of some 270 km (169 mi) away. The shock wave was observed in the air, at Dikson settlement, some 700 km (435 mi) away; and windowpanes broken at a distances of some 900 km (559 mi) away. Reflective atmospheric focusing caused the shock-wave to travel even further, breaking windows in Norway and Finland (~ 1,100 km, 684 mi, away). Although an air blast, Tzar Bomba nevertheless created an earthquake, reported by the U.S. Geological Survey to have a seismic magnitude of 5.0 to 5.25 mb; a couple of orders of magnitude less than an underground blast, that would have otherwise delivered a quake estimated at some 7.1 on the Richter scale.
Up END - Fast Neutrons & X-Rays Up
A probable source of hazards to Planet Earth

The Last Space Shuttle - NASA

01 - Lift Off - The Last Space Shuttle - 8th July 2011
STS-135: A passenger on a commercial internal US flight (believed to be a woman) catches these images on (her) cellphone; NASA

The NASA Space Transportation System (STS) manned space flight programme.
  1. Enterprise OV-101. The Test Vehicle, never went into space but was a test bed that proved the design, aerodynamics and avionics of the Space Transportation System (STS). She was first flown on the back of a Jumbo jet. She would do 5 free atmospheric flights on her own; the first ALT-12 on 12th August 1977 and last ALT-16 on 26th October 1977. It would take 4 years after this for a re-usable space system to be ready for launch in 1981.
  2. Columbia OV-102. The first reusable STS to fly space, STS-1 on 12th April 1981. She would complete 27 return missions. Colombia would fly the fourth of 4 planned service missions for the Hubble Space Telescope (HST); STS-109 on the 1st March 2002, which would also be her last completed space mission of 10 days and 22 hours with a successful return home to base. Colombia would fly her last and 28th space mission, STS-107 on 16th January 2003. Colombia died together with her 7 crew members, when she burnt up on a fiery re-entry, due to a loss of insulation tiles at launch, when returning to land at the Kennedy Space flight Centre, Florida, on 31st January 2003; some 15 days and 22 hours for mission accomplished and a successful launch. The accident would ground the NASA STS programme for 2 years before the next space flight; STS-114 of Discovery on 26th July 2005.
  3. Challenger OV-099. First flew STS-6 to space on the 4th April 1983 and would complete 9 missions. The 10 mission, STS-51-L on the 28th January 1986, would last 01m 13s; at which point supporting structures of the main liquid fuel-tank of the booster vehicle were weakened by a hot jet of gas escaping from a leaky synthetic O-seal of one of the strap-on chemical booster rockets, causing the system to break apart under aerodynamic stress, and appear to exploded to create the Challenger Disaster. There was actually no explosion; but rather a spectacular voiding of liquid propellant and oxidant from the ruptured liquid-fuel tank. On view to millions of world enthusiasts on TV, and especially to a great number of young children in the U.S.A. who were eagerly following the mission because of a civilian school-teacher aboard, Christa McAuliffe who had aspired to the rank of mission specialist out of a field of some 11,500 applicants; the Challenger Disaster was a poignant reminder that space flight and the technologies of the day were still in primitive infancy. The Challenger STS, with her 7 crew, were ruled to have died on impact in the Atlantic ocean, a few miles East of the Florida launch coast, some 2.75 long minutes after the vehicle arched away, in ballistic trajectory, from the point of rupture. The Challenger Disaster had two root causes. One, the synthetic seals of the re-usable chemical booster rockets had a flexibility characteristic that was temperature sensitive; they would harden, with sealant loss, at temperatures around the freezing point of water, 0 deg C; the prevailing ground temperature at the time of the wintery vehicle launch. Two, an unkind endemic and epidemic viral societal disease of American society called Market Forces. The accident would ground the NASA STS programme for over 2 years before the next space flight; STS-26 of Discovery on 29th September 1988.
  4. Discovery OV-103. First flew STS-41-D to space on 30th August 1984, and completed 39 missions, the highest number of the STS fleet. STS-31 launched on 24th April 1990, Discovery with a crew of 5, on a 5 day 1 hour mission, deployed the optically defective Hubble Space Telescope (HST), a joint NASA venture with the European Space Agency (ESA). Discovery would fly 2 of the 4 planned service missions for the HST; the second STS-82 on 11th February 1997 and the third STS-103 on 19th December 1999. Discovery flew STS-133, her last mission to space on 24th February 2011; to return 12 days & 19 hours afterwards.
  5. Atlantis OV-104. First flew STS-51-J to space on 3rd October 1985, and completed 33 missions. Atlantis flew the fifth and only un-planned Hubble Space Telescope (HST) update and repair mission of 12 days and 21 hours with 7 crew, occasioned by public and scientific debate in the U.S.A., during her STS-125 space flight on 11th May 2009; it was also to be the last HST service flight by STS vehicles, intending an extended HST lifespan to 2014. Atlantis flew STS-135; her last mission to space on 8th July 2011; to return 12 days & 18 hours afterwards; the last STS space flight that closed this NASA STS manned flight programme.
  6. Endeavour OV-105. First flew STS-49 to space on 7th May 1992, and completed 25 missions. Endeavour flew the first of 4 planned service missions for the HST; STS-61 on 2nd December 1993, which provided the HST with corrective optics, or ‘glasses’, that allowed the telescope for the first time to operate within its design parameters, and to return images of such astonishing clarity, that it would set the Hubble ST as one of the most influential and successful scientific instruments of its class ever deployed by mankind. Endeavour flew STS-134, her last mission to space, on 16th May 2011; to return 15 days & 18 hours afterwards.
SetUp 20120611 - - UpDate 20121211
tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_14 tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_16 tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_18 tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_21
tlss_STS-51-L_liquid-fuel-tank-collapse-at-launch_28January1986_challanger_0210 - Sad moments of Grief

Moments into the Challenger Disaster (left). STS-51-L 01m 13s post lift-off as a liquid fuel tank collapses on the 28th January 1986.

Images from video (surround): STS-107 Columbia burns up on re-entry into the atmosphere on 31st January 2003, 15 days and 22 hours for mission accomplished and after a successful launch; but had lost some protective heat-shield tiles at lift-off.

  The infectiously appealing fictional prelude “Space, the final frontier; …to go where no man has gone before”, echoed deeply within the culture of those who ventured the slow and risky climb to the stars. These small and faulting steps, continue today, on that endless ladder of human discovery. The content of these pages are testimony to those who believe the winding journey a needed task, a worthy path for mankind.

  Where science gestures in respect to the frailty of human understanding, most of its adherents nevertheless offer their abstemious sympathy with “may your Gods be with you” on this journey.

tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_25 tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_28 tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_31 tlss_STS-107_Columbia-burns-up-on-re-entry_15d-22hr-for-mission-accomplished-after-launch_31st-January-2003_37
10 - Hubble Space Telescope (HST) release by Discovery.


  STS-31 launched on 24th April 1990, Discovery with a crew of 5, on a 5 day 1 hour mission, deployed the optically defective Hubble Space Telescope (HST) [NSSDC ID = 1990-037B], a joint NASA venture with the European Space Agency (ESA).
  The Hubble Space Telescope (HST) is the worlds most famous telescope. Despite having a rough start, needing corrective lenses and is the only space telescope to have been serviced by the now extinct ‘Space Shuttle’ programme [Corrective, STS-61 2nd December 1993 (Endeavour); Planned, STS-31 24th April 1990, STS-82 11th February 1997, STS-103 19th December 1999 (all Discovery), STS-109 1st March 2002 (Columbia) and Unplanned, STS-125 11th May 2009 (Atlantis)].
  Hubble is the 20th Centuries most successful scientific instrument, having pioneered many research discoveries in physics and cosmology. She is rivalled only by the great collider at CERN (France/Switzerland/Germany) for her achievements. Although her ‘seeing power’ has been slowly overtaken by her rival great earth bound sister telescopes, they all had to play catch-up to the exemplary Hubble.
  When the Hubble goes off-line (2030–2040?), there will be many a stout heart in tears; so great is her reign in the upper skies.

The Moon - Selene

10 - The Earth from the Moon - & - The Earth's Moon
NASA + (Unknown source) probably NASA archive; Wiki

  The Moon in all its phases recorded through October 2007 displaying libration, the visual effects caused by its non-circular orbit around the earth; this allows about 58% of the face of the moon to be viewed, rather than 50% had the orbit been exactly circular.
  Alongside is a famous NASA release of 'Earthrise' as seen from moon orbit by the Apollo 8 crew on 24th December 1968; the first manned fly-by of the moon, a precurser to a manned landing on 21st July 1969.
10 - The Earth's Full Moon
2010 (Unknown source)

10 - The Far Side of the Moon
LROC WAC (moon-orbiter mosaic) 2010 Arizona State University

10 - Topology of the Moon
Data from moon orbiting satalites

  Luna topology, with an area of the far side, marked in purple, that can be seen in the following image.
10 - The unseen 'Far Side' of the Moon
LROC WAC (moon-orbiter mosaic) 2010 Arizona State University

   Locked in synchronus orbit, the rate of rotation of the moon matches the time it takes the moon to make one orbit around the earth. Called 1 to 1 orbital resonance, caused by the tidal forces due to the garvatational effects between the earth and the moon, the far side of the moon remains invisible to earth observers, as it always faces away from earth.
  A segment of a masoic image composed from moon-orbiter data provides a glimpse of the south-eastern quadrant of the moons far side. The view encompases some of the highest (top) and lowest (bottom) moon terrane as illustrated from the topographic image shown above this one.

  CAUTION: This image of moon craters should be viewed with a little caution as it can induce optical illusions to the viewer. The craters, which are concave, can be 'flipped' into appearing as convex 'bubble' formations on the moons surface. Be warned.
e-moon-05_computer-model-of-impact-theory-of-the-formation-of the-moon_Astronomy-Today
10 - The Origin of Earths Moon - Computer model of the Impact theory of the formation of the moon
Astronomy Today

  The currently accepted impact theory for the moons origin, although some facets of this have recently been disputed in 2012, postulates that the earth was hit at a glancing angle by a Mars sized planetoid, depositing its interior (heavy metals) into the (now rather molten) earth, and taking a sizable amount of crust material into earth-orbit, which then re-congealed into the satellite moon. Computer simulations (a sample of which is shown above) attest to the plausibility of this theory.
  The impact theory is the culmination of much debate about the moons origin. The similarities and differences between the moon and the earth, present serious challenges to many theories. The moon is less dense overall, than the earth, implying a small or light core. Yet the composition of the lunar surface is very similar to that of the crust of the earth, derived from analyses of Apollo ‘moon-rock’ samples of the late 1960’s and early 1970’s.
  A sister, or co-formation, theory that postulates the moon and earth forming together at the same time, from the same material; fails on the grounds of the differences between them; where the theory would expect larger similarities.
  A daughter, or fission, theory that postulates a moon thrown off a fast rotating earth planetoid; fails on the grounds that it would require an unrealistic rotation rate for the planetoid at the time of is accretion; according to current computer simulations and to present accretion theory.
  A capture theory that postulates the earth capturing a close passing planetoid; fails for reasons that the moon is too large (massive) an object to capture in this way; attempted computer simulations fail a capture outcome; other than for slowing by glancing impact.
  Thus returning to the impact theory, which is strengthened on grounds of conservation of rotational momentum, where the observe and calculated figures (wound backwards for the passage of time) show good agreement.
  The 2012 dispute apparently actually accepts the impact theory, but disputes only whether the majority of the moons crust originated from the impactor planetoid, or from the earths crust. Using new data from the Apollo 'moon-rock' samples; analysis of titanium isotopes within them indicate a very close similarity to earth crustal material.

Mars - View of Mars seen through NASA's Hubble Space Telescope true-color 1999_vote-mars-landings-10-02
10 - Mars - View of Mars - True colour.
Hubble Space Telescope 1999; NASA

Mars - Valles Marineris a system of canyons 4000 km long ranging from 2 to 7 km deep and extends across one-fifth the circumference of Mars - Viking 1 orbiter 1980_Mars_Valles_Marineris_EDIT_990w
10 - Mars - Valles Marineris, a system of canyons 4,000 km (2,485 mi) long, ranging from 2 to 7 km (0.6 to 4.4 mi) deep and extends across one-fifth the circumference of Mars
Viking 1 orbiter 1980

10 - Mars - Olympus Mons shield volcano

24km (16 mi) (78,000 ft) above the Tharsis Plateau;
Caldera 80km (50 mi) in diamater;
base 624km (374 mi) in diamater,
rimmed by a cliff 6km (3.7 mi) (20,000 ft) high.

(Sourse Unknown) - NASA

Mars - Olympus Mons shield volcano 24km(16mi)(78,000ft) above the Tharsis Plateau, caldera 80km(50mi)Dia, base 624km(374mi)Dia, rimmed by a cliff 6km (20,000ft)h
10 - Mars - Puzzle in geology - Slope Streaks in Acheron Fossae

10 - Mars - Avalanche from a 700m high cliff
Mars Reconnaissance Orbiter HiRISE true colour, 19 February 2008

Mars - The moon Phobos 28 km long by 20 km wide prograde and synchronous orbit @9,378 km from CM 7 hrs 39 mins - Mars Reconnaissance Orbiter HiRISE true colour, 23 March 2008_Phobos_colour_2008_990w
10 - Mars - The moon Phobos 28 km long by 20 km wide; prograde and synchronous orbit @9,378 km from CM; period 7 hrs 39 mins.
Mars Reconnaissance Orbiter HiRISE true colour, 23 March 2008
Mars - The moon Deimos 16 km long by 10 km wide prograde and synchronous orbit @23,459 km from CM 30 hrs 18 mins - Mars Reconnaissance Orbiter HiRISE true colour, 21 February 2008_Deimos-MRO_592
10 - Mars - The moon Deimos 16 km long by 10 km wide; prograde and synchronous orbit @23,459 km from CM; period 30 hrs 18 mins
Mars Reconnaissance Orbiter HiRISE true colour, 21 February 2008

The Lagrangian Points and Trojans

10 - The Lagrangian Points and Trojans
  Working on a problem of gravitational attraction first defined as the Three Body problem; the French mathematician Joseph Louis Lagrange in 1772 concluded that there are five points at which the gravitational attraction around the mass system, of M2 in circular orbit of M1, falls to zero. These points are now accepted as the 3-body-problem_Joseph-Louis-Lagrange_1772_polt_set-01Lagrangian Points L1 to L5.
  Mathematically, the problem is of interest where, within the limits; M2 > 0; and M2 ≤ M1. We note in passing that if M2 ≥ M1, it is the same problem as M2 ≤ M1 with the masses interchanged; and that when M2 = 0; there is no problem. The problem can be generally applied to all bodies orbiting a central mass, with a solution in two parts.

  The first part is that as long as M2 > 0; there will always exist points L4 and L5, equidistant from M2 to M1; L4 the leading and L5 the lagging, at 60 degrees. These are commonly called the Trojan points (with some modification to this name when applied to the Jovan system – see below). The L4 and L5 points are considered gravitationally stable, more so as the mass M2 increases, as any small bodies trapped in the same orbit of their locality will remain there; as long as any perturbing body or force is not too large. These points were of interest to astronomers, where Lagrange mainly considering the Sun-Jupiter system at the time, was computing where small bodies (of asteroidal size) of the system were most likely to be found. Any body found at the L4 and L5 points is considered to be in 1:1 orbital resonance with the parent body M2. We thus mainly refer to the Trojans of the gas-giants Jupiter, Saturn, Uranus and Neptune in this context; the name Trojan first being applied to the Sun-Jupiter system as the prototype; where the leading L4 is called The Greeks and the lagging L5 The Trojans.

  The second part of the solution is more dynamic. The pair L1 and L2 begin in the middle of M2 at M2 = 0, and each move outward along the line cantered on M2 an M1; to a maximum when M2 = M1;.where L1 arrives at mid distance between M2 and M1; with L2 being a little less distant. Along the same line, L3 moves outward from the circumference, in approximate reflection of L2. These are tidal nulls, and are deemed unstable points. Although representing a null gravity point, any perturbing force is likely to move the body out of its location at that orbit. These points are however favoured for specialist artificial satellites.
  As an example, within the Sun-Earth system, the L1 point was used as the parking orbit for ESA’s Solar and Heliospheric Observatory (SOHO) satellite (1995) that kept constant watch on the sun and assisted with solar weather forecasting; it needed minimal thrust adjustment to remain on station.
  Another example is with close or transfer binary stars; where provided their Roche lobes are in contact; the outer envelope of the more expanded star will commit transfer of its envelope gasses to its companion, through the L1 point.
The Asteroid Belt

asteroids_02_Inner Solar System_600w 10 - The Asteroid Belt & The Inner Solar System
View looking down from North on the ecliptic plane as of 14th August 2006. Data the JPL DE-405 ephemeris, and the Minor Planet Centre database (MPCD) of asteroids re: 6th July 2006.
25 January 2011 Orion 8; 15 April 2007 Dronemvp

  The inner Solar System extends from the sun out to Jupiter, which includes the terrestrial planets Mercury, Venus, Earth and Mars, the near-Earth asteroids, the orbital association of objects in the Asteroid Belt, the Jupiter Trojans and the group of debris called the Hildas.

  The Asteroid Belt is referred to by astronomers as the Main Asteroid Belt, or Main Belt, to distinguish it from other objects like the Jupiter Trojans and the Hildas as examples; but includes some bodies now defined as dwarf planets.

  The name asteroids is attributed to the astronomer William Herschel, who in 1802 suggested they be placed into a separate category because of their appearance, citing the Greek asteroeides, meaning star-like.
  From present understanding of the accretion theory of the solar system, it is believed that the asteroids represent a group of primordial planetesimals formed within their general orbits, but were prevented from accreting into larger masses by the gravitational disturbance of an early era Jupiter. Jupiter’s gravitational perturbation is believed to have prevented their growth and caused the objects to instead collide and remain fragmented.
  Computer simulations suggest that the original asteroid belt may have contained a mass equivalent to that of the Earth, but consequent gravitational perturbations ejected most of the material within around a few million years of formation, leaving behind less than 0.1% of the original mass. Since that time, asteroids are considered to have evolved through collision, bombardment and solar weathering, to the material found today.

  Any asteroid above a radius of about 100km in diameter, may be considered as primordial, though not many of them have been discovered (~200); in that when they formed, they could have been sufficiently hot to have a melted interior that differentiated into a metallic core with a silicate type exterior. It is even postulated that there were larger bodies sufficient to exhibit volcanism. However this period of protoplanetary evolution was brief, occurring within the first few million years of the accretion of the solar system.

  Today, examples of asteroids discovered [MPCD names used], range in size from the dwarf planet 1 Ceres [discovered by Giuseppe Piazzi on 1st January 1801] at 961 kilometres (597 miles) in diameter, dwarf planet 2 Pallas [Heinrich Wilhelm Olbers in April 1802] 544 km (338 mi) in dia., 3 Juno and 4 Vesta by 1807 - 4 Vesta 529 km (329 mi) in dia. pocked by impact craters and ground with rotational impact grooves; 10 Hygiea [Annibale de Gasparis on 12 April 1849] 350–500 km (217-311 mi) oblong diameters; 243 Ida [Austrian astronomer Johann Palisa on 29 September 1884] 101 km (36 mi) in dia., 253 Mathilde [Austrian astronomer Johann Palisa on 12 November 1885] 50 km (31 mi) in dia., 433 Eros 34 km (21 mi) in dia. and 951 Gaspra [Russian astronomer G.N. Neujmin in 1916] 19 km (12 mi) long, pocked and potato shaped; to rubble piles like the potato shaped Itokawa; and down through 1,000m sized boulders (700,000 to 1.7 million estimated from infra-red surveys made by 2002), to dust.

  By mid 1868 over 100 asteroids had been located; in 1891 Max Wolf’s introduction of astrophotography accelerated the rate of discovery. By 1921 a total of 1,000 asteroids had been found, 10,000 by 1981 and 100,000 by 2000. Modern asteroid surveys, using automated systems, now locate new minor planets and asteroidal type objects in ever-increasing numbers; with no upper limit; counting stones is pointless, but finding them may be important for future mining, habitat and space navigation.
10 - 4 Vesta - Divalia Fossa trench - These parallel trenches are usually several hundred km long, up to 15 km (9 mi) wide and more than 0.8 km (0.5 mi) deep.
Dawn space-probe January and April 2012, global artificial-projected mosaic from altitude of 210 km (130 mi); NASA, JPL

  Interpreted as the result of two large asteroid impacts far in the southern hemisphere, demonstrating that impact events that occurred hundreds of km apart caused shocks throughout Vesta (see full image of 4 Vesta below) and altered its surface. This suggests Vesta was in a plastic phase following the impacts.
  Alternatively, as these grooves are around an equatorial region of a rotating body, they could be the result of Vesta grinding against a close body long in the past.
10 - The Kirkwood Gaps
Based on plot by Alan Chamberlain, 2007; JPL-Caltech

asteroids_01_Kirkwood_Gaps_450w   The astronomer Daniel Kirkwood discovered in 1866 that there were gaps in the orbits of the asteroids, orbits at which there were fewer than expected, or no asteroids, present. Kirkwood proposed that these gaps were caused by the gravitational effects of Jupiter, fundamental and harmonic resonances, that would move and clear these orbits of bodies within them, to higher or lower orbits. These orbits are now termed the Kirkwood Gaps.
  The Kirkwood Gaps are not apparent in a direct plot of asteroid positions (see above) within the asteroid belt, but are a mathematical relation to the determined semi-major axis of the bodies orbits; as the bodies will appear as a random scatter of points on a map as they trace their eccentric and inclined orbits.
  This recent histogram displays the primary Kirkwood Gaps in the asteroid main-belt. The Jupiter to asteroid mean-motion gravitational resonance positions are noted in the gaps as: 3:1, 5:2, 7:3 and 2:1.
  A 5:2 resonance, for example, means that the asteroid completes 5 orbits for every 2 orbit of Jupiter.

  Astronomers sometimes apply zoning to the Kirkwood gaps.
Zone I lies between the 4:1 resonance (2.06 AU) and 3:1 resonance (2.5 AU).
Zone II continues from the end of Zone I out to the 5:2 resonance gap (2.82 AU).
Zone III extends from the outer edge of Zone II to the 2:1 resonance gap (3.28 AU).

  Other gaps have been found related to Mars to asteroid gravitational resonances.
asteroids_10_Orbital dispersion_eccentricity_e-vs-a_ref-wiki_450wasteroids_11_Orbital dispersion_inclination_i-vs-a_ref-wiki_450w
10 - Plots for the Asteroids: Eccentricity vs semi-major axis & Inclination vs semi-major axis
Using data from the Minor Planet Centre orbit Database (MPCD); 8th Feb 2006.
By Piotr Deuar 4th December 2006 (Eccentricity); 20th February 2006 (Inclination).

  Inwards of about 6 AU; 120,437 numbered minor planets are used in these plots of eccentricity and inclination vs their respective orbital semi-major axis.
  For reference; Mars orbits out to 1.666 AU and Jupiter between 4.95 and 5.46 AU.

  ECCENTRICITY plot (left):
  The main belt is shown in red and blue; and contains 98.5% of all the objects.
  Within this, the core region between the 4:1 (2.06 AU) and 2:1 (3.27 AU) Kirkwood gaps, is shown in red; accounts for 93.4% of all the objects.

  INCLENATION plot (right):
  The main belt region is shown in red, and contains 93.4% of all the objects.

  Similar to the orbital example of 1 Ceres (above); most asteroids have eccentric and inclined orbits. These plots, apart from confirming the Kirkwood gaps, also indicate that the inner asteroids, particularly the group nearer to Mars, have higher inclinations than the main belt objects, yet have modest eccentricities.

  The objects shown (black) at ~ 5.25 AU represent the Jupiter Trojans (+ the Greeks).
10 - Asteroidal families – Plot of Eccentricity vs Inclination
Using data from the AstDys web
By Piotr Deuar 19th January 2008
Computations by Z. Knezevic and A. Milani

  Inwards of about 6 AU; 96,944 numbered minor planets are used to plot eccentricity vs inclination to indicate trends in orbital distribution of the asteroids. Strong clumping is clearly demonstrated, suggesting that the fragmented material originated from parent bodies now broken and ground to smaller pieces by collision; and through impacts from other orbiting objects. There are clearly of the order of 25+ groupings or clusters of asteroids indicated; in families with similar orbital parameters, as first suggested by the Japanese astronomer Kiyotsugu Hirayama in 1918.

  It would be interesting for Deuar/Knezevic/Milani to have generated a similar but tri-colour plot of these bodies to include their estimated compositional parameters (if available) as well. This refers to the classifications of C-type or carbonaceous asteroids, S-type or silicate asteroids, and M-type or metallic asteroids (see below).

asteroids_12_Orbital elements_inclination+eccentricity_i_vs_e_ref-wiki_450w
asteroids_40_1-Ceres(optimised)Dwarf-planet&largest-asteroid,961km(597mi)dia_Imaged-from-1.64AU_HST23Jan2004col_NASA,ESA,J-Parker(SRI)_246w asteroids_41_2-Pallas_Dwarf-planet-&-2nd-largest-asteroid,544km(338mi)diameter_B-type_HSTSep2007_Ultra-violet_PallasHST2007_246w asteroids_47_5535-Annefrank_6.6×5.0×3.4km,Imaged-from-3079km_Stardust-mission2Nov2002_NASA_5535_Annefrank_246w asteroids_49_2867-Steins-1969VC(Diamond)_6.67x5.81x4.47km_E-type_Rosetta-probe_5Sep2008,ESO_Steins-Rosetta_246w
10 - 1 Ceres (optimised)
A dwarf planet and the largest asteroid, 961 km (597 miles) in diameter.
Imaged from 1.64 AU
(245 Meg km; 152 Meg miles)

HST 23 January 2004 colour
NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), and L. McFadden (University of Maryland, College Park)
10 - 2 Pallas
A dwarf planet and the 2nd largest asteroid, 544 kilometres (338 mi) in diameter.
B-type asteroid

HST Ultra-violet
September 2007;
10 - 5535 Annefrank
6.6×5.0×3.4 km
(4.1x3.1x2.1 mi);

Imaged from 3,079 km (1,913 mi)

Stardust mission
2 November 2002;
10 - 2867 Šteins - 1969VC (The Diamond)
6.67x5.81x4.47 km
(4.1x3.6x2.8 mi)
E-type asteroid

Rosetta space probe
5 September 2008;
European Space Operations Centre
  The composition of the asteroids is derived from a combination of studies involving both observational astronomy, and data collected from the chemistry of meteorites, some 50,000 bodies so far collected on earth, 99.8% of which are believed to have originated from the asteroid belt.

  Observationally it has been found that the asteroids very in brightness due to the composition of their surface material and to their geological chemistry. Brightness studies can yield information on size, and spectroscopic analysis points to their surface chemistry, and hence emissivity (how much light they reflect); which in turn confirms an order of brightness to expect, which then feeds back to brightness/distance/size calculations.

  The categorization of asteroids began with observations of their spectroscopic properties.
   The darkest, or least reflective, are classified as C-type (or carbonaceous) as they are understood to contain a large amount of carbon, with some rocky material, in their makeup; these comprise about 75% of all asteroids.
  The next group are brighter, of high albedo, called the S-type (or silicate) that contain high proportions of rocky, or silicate, material with a low percentage of metal; these comprise about 15% of all asteroids. The final 10% being classified as all the rest, and of intermediate brightness.
  Most of this further group are classified as M-type (or metallic) composed mostly of a mixture of iron and nickel; thought to be fragments of a differentiated metal core of a broken up larger body.
  Another, but rear, V-type (named after asteroid 4 Vesta as the prototype) are supposedly basaltic in nature; and at first, thought to be fragments of 4 Vesta itself; of the family Vesta (see above).

  4 Vesta, despite its small size, appears to have had processes of volcanism in its past; hence the expectation for basalts. Basalts, similar to terrestrial volcanic material, have been found in many of the meteorites studied. There has arisen a debate that there is a marked absence of basaltic asteroids within the brace so far discovered.

  The V-type category now appears wider, and less confined to 4 Vesta, than previously thought with the discovery of asteroid 1459 Magnya, having a basalt of slightly different chemical composition to 4 Vesta. And not from the Vesta family, found in 2007, asteroids in the outer belt, 7472 Kumakiri and (10537) 1991 RY16, are noted to have further differences in their basalts. However, with the difficulty of observing and analysing these small and distant objects, their study is still in its infancy, and much theory will be corrected in the future.

  The S-type asteroids are found to populate the inner regions of the belt, with a steady increase towards the C-type the further out their orbits.

  Present temperatures within the main belt very from about 200 K (−73 °C) at 2.2 AU, down to about 165 K (−108 °C) at 3.2 AU. Integrating the asteroids into a model for understanding the genesis of the solar system, astrophysicists contend that at the temperatures prevalent during the formation of the early solar system, at a distance beyond around 2.7 AU from the sun, existed a snow-line over which water molecules would freeze to ice. This happens to be in the middle of the asteroids main belt. So bodies outward of this region could form icy conglomerates of water and rubble, familiar today as cometary bodies. In 2006 astronomers noted that a population of such bodies had been discovered.
asteroids_45_253-Mathilde_50km(31 mi)dia_primitive-Cb-type_Imaged@2,400km_NEAR-Shoemaker(on-fly-by-to433-Eros)27Jun1997_NASA_253_mathilde_260w_256h asteroids_48_Itokawa_100120-asteroid-02_ISAS+JAXA_438w_256h asteroids_46_951-Gaspra_S-type_Galileo(on-Jupiter-fly-by)29Oct1991,colour-exaggerated_NASA_951_Gaspra_292w_256h
10 - 253 Mathilde
50 km (31 miles) in diameter.
A primitive Cb-type asteroid.
Imaged at 2,400 km (1,491 miles)
NEAR-Shoemaker spacecraft (on fly-by to 433 Eros) 27 June 1997; NASA
  10 - Itokawa 100120
A conglomerate of rubble

ISAS; JAXA (Japan)
10 - 951 Gaspra
19 km (12 mi) long, pocked and potato shaped.
S-type asteroid.
Galileo (fly-by on route to Jupiter) 29th October 1991; colour exaggerated; NASA
  Most asteroids have an eccentricity between 0.05 and 0.3, which constrains their orbits to lie mainly between Mars and Jupiter. A few however have higher eccentricities; and when their semi-major axis lies at just over 1 AU, they may also classify as earth-crossing asteroids, as they pass within the orbit of the Earth. These are classified as the Apollo asteroids, named after the first of the type discovered, the named prototype Apollo. Other extended wonderers are termed the asteroids_30_number-impacts-on-earth_vs_years_ref-Astronomy-Today_375w_305h_02 Aten asteroids; and those that cross the orbit of Mars, the Amor asteroids. It is suggested that the principal moons of Mars, Phobos and Deimos, are captured asteroids, having similar asteroidal geophysical characteristics.
  As can be attested from the images of the inner Terrestrial planets, and more locally the Earth’s moon, most bodies have been impacted long after their initial accretion, and after having cooled sufficiently to form a stable crust; in a timescale of the order of the first 1 Gig years or so. Many of the impactors are attributed to Jupiter’s gravitational clearing of the asteroid belt. Some of the icy asteroids have been attributed to supplying the Earth with water, as the estimated amount of out-gassed water during crustal formation and volcanism is insufficient to account for the amount of water the planet holds. It is also possible that the water suspected to have been present on a youthful Mars, now long evaporated away, arrived by the same processes. The frequency of impacts has substantially subsided over time, with an estimate for the end of major impacts occurring about 2 to 2.5 Giga years post accretion. But this fall has been exponential, and still continues, albeit at a very low level today.
  Since 1990, surveys for earth-crossing asteroids accounted some 1,200 objects by 2001; with some 300 of these being larger than 150m in diameter, and in orbits that pass within 0.05 AU (7,500 km; 4,600 kmiles) of earth, to merit the classification of being potentially dangerous. It is estimated that about 3 major asteroidal or cometary impacts occur on Earth every 1,000,000 years. The extension of the dinosaurs is attributed to a 10km - 15km diameter object that impacted some 65 Meg years ago.
10 - 4 Vesta - 529 km (329 mi) in diameter. A view of both sides of this oblate spheroid, distorted by heavy impacts.
Dawn January and April 2012 computer mosaic; NASA; JPL-Caltech; CLA; MPS; DLR; IDA

  Vesta is thought to consist of a metallic iron–nickel core some 214–226 km (133-140 mi) in diameter, an overlying rocky olivine mantle, with a surface crust.
  Despite the low temperatures reported for the asteroid belt, solar radiations impact on the asteroids, unimpeded by atmospheres, to irradiate them with light, heat and erode their surfaces with ionised solar particles. Slowly rotating bodies will have large temperature differentials between their exposed surfaces and shadowed backs, which radiate to the stellar background. So their temperatures fluctuate as they rotate. Sufficient to cause cracking in the rocky materials, according to some authorities.

  An unusual effect of solar radiation is reported to actually promote, and increase, the spin of some irregular shaped asteroids, of sizes a little less than 10km along a long axis; somewhat like driving a wind-mill; but these changes in speed, occur over periods of millions of years. The result however, is that the induced rotation can cause the body to split apart by the centrifugal forces resulting. Called the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect; the imbalance between sunlight absorbed on one side of an out-of-round asteroid, and heat radiated on the other side, causes it to spin.
asteroids_52_Binary-asteroid_(2)_ESO,L-Calcada_1-internationa_400w_275h asteroids_50_243Ida&Dactyl(first-binary-asteroid-found)_Galileo28Aug1993@range-of-about-10,500km(6,500mi)_NASA,JPL_PIA00333_400w_275h
10 - Binary asteroid
Split by (solar) rotation

ESO; L Calcada

10 - First binary asteroid discovered
243 Ida & Dactyl [inset] (first confirmed satellite or moon of an asteroid).
Imaged at a range of about 10,500 km (6,500 mi)
Galileo (fly-by on route to Jupiter) 28th August 1993; NASA, JPL

243 Ida - 200-300 km (120-180 miles) in diameter, S-type;
Dactyl - 1.2 x 1.4 x 1.6 km (0.75 x 0.87 x 1 mile) across, S-type
The Jovan Gas Giants: Jupiter - Saturn - Uranus - Neptune

The Jovan Gas giants - Jupiter, Saturn, Uranus and Neptune in scale of size_outer_planets_small_2_600w
10 - The Jovan Gas Giants compaired by size - Jupiter, Saturn, Uranus and Neptune to scale

Jupiter - The largest planet in the Solar system and thus for the Gas Giants - HST Enhanced image_873w
10 - Jupiter - The largest planet in the Solar system and thus for the Gas Giants
HST Enhanced image

Jupiter - The Great Red Spot first observed in 1630, 14Kkm (8,700mi) wide, 40Kkm (24,855mi) long rotates anticlockwise every 7 days - Enhanced image Galileo 1995_990w
10 - Jupiter - The Great Red Spot first observed in 1630, 14Kkm (8,700mi) wide, 40Kkm (24,855mi) long, rotates anticlockwise once every 7 days
Galileo probe 1995 Enhanced image

  Two Earths, of diamater of 12,756km (7,926mi) x 2 alongside, could be squeezed to fit into the Great Red Spot.
Jupiter showing debries of impact in its upper atmosphere from comet Shoemaker-Levy 9 (SL9) on 18-07-1994 - HST_hs-1995-49-d-full_tif_990w
Jupiter - Comet Shoemaker-Levy 9 impacts Jupiter mid-1994

10 - Jupiter showing debries of impact in its upper atmosphere from comet Shoemaker-Levy 9 (SL-9) on 18th July 1994

  The Great Red Spot of Jupiter is visible on the lower left. The dark smudges of in-line multiple impacts of comet SL-9 trail to the upper right. Each impact averaged around 25,000 Mega tons TNT (equivalent); where the furthest circular mark on the upper right represents a disturbance twice the diamater of the planet Earth.

Right image: Astronomy Today [Annotated by author]
Jupiter - And a satellite moon Ganymede - HST_hubblejupitercallisto_990w
10 - Jupiter - And a satellite moon Ganymede
HST, WFPC2, 9th Apr 2007; NASA, ESA, E Karkoschka, Uni of Arizona

  The 4 prominent satellite moons of Jupiter; Io, Europa, Ganymede and Callisto, were first observed by Galileo Galilei in about 1610 after he had fabricated his own telescope; following a story he had heard about a Dutchmans spyglass the year before. Copies of a Jesuit monks observations of the same exist from 1620. This observation of the moons orbiting a planet, inspired Galileo to support the Copernican view (1543) of a Heliocentric (Sun centred) universe; as modified by Kepler (1594) with elliptical orbits.
  Galileo finally published his support for the Copernican view in 1613. This infuriated the Catholic Church, whose dogma was that the earth was the centre of the universe. In 1632 Galileo published an updated version of his treatise and was consequently put under house arrest in 1633, till his death in 1642; and his works restricted or 'banned' by list in the Index of the church. Despite Galileo’s intransigence however, he did not adopt Kepler’s proofs of elliptical orbits, although it has been suggested that he had knowledge of that work; preferring instead to keep hold to the traditional and ideal views of harmonious circular orbits, as first postulated by Ptolemy (around 100 to 200 A.D. - and whose postulate of a geocentric [earth-centered] system was favoured by the R.C. church).
  202 years later, in 1835, the works of Copernicus, Kepler and Galileo were removed from the Index. In 1992 the Vatican admitted error to Galileo, and apologised; thus sundering some 360 years of religious dogmatism.

  Jupiter is now known to have additionally over 60 lesser satellites in orbit around it.

Saturn_The-Cassini-orbiter-approaches-Saturn_Cassini27Mar2004_true-colour_NASA,JPL,Space-Science-Institute,Boulder,Colorado_800w_470h 10 - Saturn [Upper image]
HST 1995

10 - Saturn [Left image] – The Cassini orbiter approaches Saturn.
Cassini 27 March 2004 true-colour - NASA, JPL-Caltech, Space Science Institute, Boulder, Colorado

  Cassini’s narrow-angle camera takes its last full view of the Saturn’s rings, before being too close, at a spacecraft distance of 47.7 million kilometers (29.7 million miles) from approach to Saturn.
  Moons visible in this image are (clockwise from top right): Enceladus 499 km (310 miles), Mimas 398 km (247 miles), Tethys 1,060 km (659 miles) and Epimetheus 116 km (72 miles). Epimetheus is dim and appears just above the left edge of the rings. Brightness’s have been exaggerated to aid visibility.
  The bright blue sliver of light in the northern hemisphere is sunlight passing through the Cassini Division in Saturn's rings and being scattered by the cloud-free upper atmosphere.
Saturn_Advances-toward-equinox_Cassini23July2008_Cassini-Huygens-MissionNASA,JPL,Space-Science-Institute, Boulder,Colorado_990w
10 - Saturn - Advances toward equinox (above)
Cassini 23 July 2008 - Cassini-Huygens Mission – NASA, JPL, Space Science Institute, Boulder, Colorado

  Six moons of Saturn are captured in this reconstructed image; with diameters shown. Titan 5,150 km (3,200 miles), Janus 179 km (111 miles), Mimas 396 km (246 miles), Pandora 81 km (50 miles), Epimetheus 13 km (70 miles) and Enceladus 504 km (313 miles).
  This mosaic combines 30 images — 10 each of red, green and blue light—taken over the course of approximately two hours as Cassini panned its wide-angle camera across the entire planet and ring system on 23rd July 2008, from a southerly elevation of 6 degrees.
  From a distance of approximately 1.1 million kilometers (690,000 miles) from Saturn and at a sun-Saturn-spacecraft, or phase-angle of 20 degrees. Image scale is 70 kilometers (43.6 miles) per pixel.
  At resolution shown here, moons Pandora 81 km (50 miles) and Epimetheus 13 km (70 miles) will not be visible; this image having been compresses by a factor of 4.7 : 1. Janus 179 km (111 miles) is just visible – close under the right-side ring-tip.
10 - Saturn – Storm in the Northern sector processed in true-colour; as seen from the Cassini orbiter.

Cassini 11 March 2012 true-colour - NASA, JPL-Caltech, Space Science Institute, Boulder, Colorado

Saturn_double-aurorae_HSTJan2009NASA,ESA,Jonathan-Nichols(University-of-Leicester)_450w Saturn_North-polar-vortex_Cassini-orbiter_Cassini27Nov2012_P0&CB2-filters_un-calibrated_NASA,JPL,Space-Science-Institute,Boulder,Colorado_450w
10 - Saturn's double aurorae
HST January 2009 - NASA, ESA, Jonathan Nichols (University of Leicester)

Saturn_Aurora-on-Saturn-during-a-solar-storm -in-1998_HST1998Ultra-violet_NASA_Astronomy-Today_245w_246h

Saturn - Aurora on Saturn during a solar storm in 1998
HST 1998 Ultra-violet - NASA

Astronomy Today

10 - Saturn - North polar vortex as seen from the Cassini orbiter.
Cassini 27 November 2012 P0 and CB2 filters - NASA, JPL-Caltech, Space Science Institute, Boulder, Colorado

  Saturn north polar vortex, view taken from a distance of 400,048 km (248,578 miles) by Cassini; this preview image has not been validated or calibrated (new-data to be published in 2013).

  First noted in Voyager images from around 1988, the persisting hexagonal standing-wave pattern and the north polar vortex, again recorded by Cassini, remains challenging to explain by space scientists. The Polygonal shapes have however been replicated in the laboratory through differential rotation of fluids. The same standing-wave phenomenon has not been found at Saturn’s South pole; just an 8,000 km (4,971 mile) hurricane-like storm, locked to pole, that had a clearly defined eyewall; was reported by NASA in November 2006.
  Cassini project scientists report that the straight sides of the hexagon, of the North vortex, are each approximately 13,800 km (8,600 mi) long, making them larger than the diameter of the Earth. The entire structure rotates with a period of 10h 39m 24s (the same period as that of the planet's radio emissions) which is assumed to be equal to the period of rotation of Saturn's interior. The hexagonal features do not shift in longitude like the other clouds in the visible atmosphere. (Wiki)
Saturn_Advances-toward-equinox_Cassini23July2008_Cassini-Huygens-MissionNASA,JPL,Space-Science-Institute, Boulder,Colorado_set-02_rings_990w
10 - Saturn's rings; and moons Mimas 396 km (246 miles) [lowest], Janus 179 km (111 miles) & Epimetheus 13 km (70 miles)
Cassini 23 July 2008 - Cassini-Huygens Mission – NASA, JPL, Space Science Institute, Boulder, Colorado

10 - Saturn eclipsing the sun as seen from the Cassini orbiter.
Note the fainter outer rings, well outside the bright rings more prominent in the images above.
Cassini 15 September 2006 - NASA, JPL, Space Science Institute, Boulder, Colorado

Saturn viewed with rings edge-on but shaddowed on the planet and Titan - HST_saturntitan2_cassini_1200_990w
10 - Saturn viewed with rings edge-on but shaddowed on the planet. Seen in an orbital plane co-incident with the rings, a view of the second largest moon in the solar-system, Titan; with a diamater of 5,150 km (3,200 mi).
Cassini 11th May 2012; Cassini-Huygens Mission, NASA/JPL/Space Science Institute

  About a 200 km (124 mi) thick band of Saturn's cold and clear stratosphere is seen as a blue haze around the planets 'surface' which is actually itself a haze of clouds of ammonia ice. It is visable only because the light reflected from the bright ‘surface’ is scattered by the molecules in the upper atmosphere above it. The stratosphere is a sample of atmosphere composed mainly of molecular hydrogen (92.4 percent), helium (7.4 percent), methane (0.2 percent), and ammonia (0.02 percent).
  There is also a similar haze of Titans atmosphere visible in the image. Titan has a smoggy atmosphere with trace levels of hydrogen gas, the hydrocarbons ethane and propane, and carbon monoxide; but is mainly composed of nitrogen (~ 90 percent) and argon (at most 10 percent), with a small percentage of methane. The composition having been determined by analyses of data provided by radio and infra-red probing of the Voyager 1 fly-by in 1980.
  The large mass of Saturn, and its location away from the sun that allows its atmosphere to be very cold, have provided the conditions that Saturn retains its light gasses; hydrogen and helium in particular. However Saturn's atmosphere is unusually deficient in helium; in the ratio to hydrogen as theoretical models would expect. To account for this anomaly, it is postulated that a percentage of the helium has rained out of the atmosphere to settle further into the planets interior; thus reducing the expected abundance. But the rain will not have fallen into a sea, there is no hard surface to fall on in the upper layers, as this is a gas planet. Models of the interior infer that the helium will have sunk more than two thirds of the way into the planet, to mix with, or go beyond, a hot shell of ‘metallic’ hydrogen that occupies a layer above a small interior core of heavy materials; similar in composition to that of the Terrestrial planets.

Uranus as a virtually featureless planet in visible light as imaged by the Voyager 2 interplanetary mission spacecraft fly-by in 1986
10 - Uranus as a virtually featureless planet in visible light.
Imaged by the Voyager 2 interplanetary mission spacecraft fly-by in 1986

10 - Uranus - A false-colour image of the planet, its rings and six of its satellite moons.
HST 1997

Uranus - A false-colour image of the planet, its rings and six of its satellite moons - HST 1997_Uranusandrings_500w
Uranus - Progressive tilt of rings, 2003, 2005, 2007 with South pole at left where equator lies directly below the rings - HST ACS-HRC WFPC2 14-07-2007 Near-infrared
10 - Uranus - A view of the rogressive tilt of rings, from 2003, 2005, and through to equinox 2007; with South pole at left, where equator lies directly below the rings
HST 14th July 2007 - ACS-HRC WFPC2 Near-infrared

  AT equinox on 14th August 2007, visible every 42 years, twice per ponderous 84-year orbit; the rings of Uranus were not know to exist at its previous equinox in 1965.
Uranus - Plot of rings and satellite moons around the planet_507px-Uranian_rings_scheme 10 - Uranus
Plot of rings and satellite moons around the planet

  In doubt for nearly 200 years because of the simplicity of his equipment, the British astronomer William Herschel in 1789 accurately described the 'epsilon' ring's size, red colour and its angle of inclination relative to Uranus's orbital position.

  Serendipitously the modern existence of the rings was confirmed by James L Elliot, Edward W Dunham, and Douglas J Mink on 10th March 1977. This group were investigating the composition of Uranus's atmosphere by its occultation of the star SAO 158687. On analyses of their data using the Kuiper Airborne Observatory, they discovered 5 dips in the stars intensity as it led into, and outof, the transient behind Uranus. They later identified 4 additional thin rings.

  The fly-by of Voyager 2 in 1986 provided image confirmation of this discovery, with the addition of 2 fainter rings. The HST contributed in December 2005 by the discovery of two additional rings, the largest, at twice the distance of the previous set; together with two satellite moons, of which Mab occupies the same orbit as the largest ring.

  The colour of the rings, the larger blue and the inner red, was provided by a group from the Keck Observatory in April 2006.
10 - WM Keck and Subaru observatories atop Mauna Kea, Hawaii
Lasers point to form an artificial guide star for the adaptive optics systems.

Background image:
WM Keck spotting; Stars blur from 3 minute fixed camera exposure; 11th December 2006 Paul Hirst
(top right) WM Keck & Subaru spotting; 2012 Adam Eliott + Mauna Kea blog
(top left) Two Keks spotting; Dan Birchal
(lower centre) WM Keck & Subaru observatories, Mauna Kea, Hawaii; (Unknown source)


Neptune - Voyager 2 image of 1989
10 - Neptune
Voyager 2 image of 1989

telop_WM-Keck-Observatory_Mauna-Kea_Hawaii_pre-dawn-moments-before-shutters-close_Rick-Peterson_CF015300_580w_872h 10 - WM Keck Observatory
Mauna Kea, Hawaii

Moments before the shutters close

Rick Peterson
Pluto_symbol_25px_009999_RGB134340 Pluto - The dwarf planetPluto_astrological_symbol_set-3_25px_009999_RGB

10 - 134340 Pluto [Formally Pluto]; and Charon or 134340 Pluto I [Formally S/1978 P1]
HST - European Space Agency's Faint Object Camera - 21st February 1994
Dr R Albrecht, ESA/ESO Space Telescope European Coordinating Facility; NASA.

  HST provides Pluto diameter of 1,440 miles (2,320 km), Charon diameter 790 miles (1,270 km) [±1%]; Showing a separation of 12,200 miles (19,640 km).
  The orbit of Charon is gravitationally locked by tidal forces in synchronous rotation with Pluto; so both always face each other; with an orbital period of 6.3867 days [Average separation: 12,160 miles (19,570 km)]. Astronomers consider the system a binary, as the centre of gravitation (barycentre) [the point about which both rotate] lies outside the body of Pluto. The rotational axis of Pluto, also shared with the orbit of Charon (which is equatorial), in similarity to Uranus, is highly inclined and tilted at 119.591° ± 0.014° to its orbital plane. This will induce severe seasonal shifts, including periods of days and nights over the poles, that will last for periods of over 100 years, in the 246.04 Earth years the dwarf planet takes to orbit the sun.

PLUTO the dwarf planet
   The International Astronomical Union (IAU) demoted Pluto to a 'dwarf planet' on 24th August 2006, and renamed it in the list of minor planets as 134340 Pluto. This followed the discovery of the minor planet 2060 Chiron in the Outer Solar System and many similar objects since, notably the Scattered Disc Object Eris in 2005, which is 27% more massive than Pluto.

  Pluto was previously designated the 9th planet for some 76 years after its discovery on 18th February 1930 by 24 year old Lowell Observatory astronomer Clyde Tombaugh, a discovery which was officially announced on 13th March 1930. Pluto had been the stand-in for the fabled ninth Planet-X vainly sought by the Observatories philanthropic builder and famous astronomer Percival Lowell, who had been looking for it between 1894, when the observatory opened, and up to his death in 1916. The search followed from the idea similar to the discovery of the eighth planet Neptune, which had been theorised to exist from perturbations noted in the orbit of Uranus; about which calculations indicated where the distorting planet could be found, and was consequently discovered; the non-circular orbit of Neptune promoted early attempts to find an earth-sized perturbing Planet-X. Tombaugh, given the task by the 1929 director Vesto Melvin Slipher, found Pluto, after nearly a year of work, by systematic survey of an area of the sky which was photographed by patches, each taken about 2 weeks apart in time; then using a 'blink comparator' to find a spot that jumped (= movement) when the same areas were compared. It took astronomers nearly 50 years later to prove that Planet-X was a myth; having then arrived at better mass estimates for the known planets, especially Neptune. Also, Pluto's mass, 0.2 MEarth, proved far to small to have had any significant perturbing effect anyway. Pluto's small mass had also brought its planetary status into question. The discovery of Pluto's satellite Charon in 1978 allowed its mass to be estimated. But it was the discovery of the additional satellite moons, Nix and Hydra in 2005 (See later paragraph) that allowed a better estimate of Pluto’s mass, that together with a more recent understanding of the formation of the solar system, and the theory of the formation of the Kuiper belt, placed Pluto in the category of a Kuiper object; and from which as a member of the Scattered Disc Objects it names itself, and the class of similar sized objects, Plutions.
  The discovery of a 'new planet' in 1930 was world news, and over 1,000 names came into the Lowell Observatory for review. A precocious 11 year old school girl form Oxford, England, Venetia Burney (1918–2009)(Wikipedia), with an eye to the classics and an unusual interest in astronomy, and who probably had an understanding of the astronomical tradition for using the names from Greco-Roman mythology in the naming of planets, suggested 'Pluto', the Roman name for the Greek god of the underworld and home of the dead, Hades; as a good fit for a remote dark planet. Her grandfather, Falconer Madan, a former librarian at the Bodleian Library, University of Oxford, was taken by her idea, and passed it on to Professor Herbert Hall Turner at the University; who then cabled it to colleagues in the United States. Pluto_Charon-Discovery-image_7th-July-1978_by_James-Christy_(NOFS)_set-2_450wAt the Lowell Observatory each member had a vote from a final short-list of 3 names; Minerva, Cronus and Pluto. They all voted Pluto; some speculate that in addition to being an excellent choice of name, implicit are the initials 'PL' for Percival Lowell their past sponsor; and astronomers love puns; there could not have been a better fit.

  The official discovery of Charon, Pluto’s first moon, was announced on 7th July 1978 from the US Naval Observatory Flagstaff Station (NOFS), Arizona. Close examination of images (inset) taken by the 1.55-meter (61-inch) Flagstaff telescope revealed a ‘bump’ on the distant planet that was to small for resolution by this earth-bound instrument.
  The name ‘Charon’ was proposed by the discover James W Christy, on 24th June 1978; cloning his wife Charlene's nickname, 'Char', in hopeful witticism to be classical. It was a superb guess. Hades, the realm of the underworld and home of the dead ruled by its Greek namesake, was too dread a word to speak by the Romans, who used the Roman god Pluto in his stead; was accessible only by five rivers, one of which is Styx, the river of hate, reputed to be cold and of black waters. For safe passage of the dead, a tithe of a coin under the tongue would assuage the ferryman of the dead over Styx, whom in Greek myth was surly, white haired and had eyes of fire, and was named Charon. The name was officially accepted by the IAU on the 3rd January 1986.
Pluto_P4-28June2011_P5-7July2012_WFPC3_HST_ESA_NASA_M-Showalter_SETI-Institute_set-02_600w  To date, there have been 4 further satellite moons discovered to orbit Pluto. Nix (Formally S/2005 P1) and Hydra (Formally S/2005 P2) were discovered late in 2005 by a team using the HST; and are estimated to be between 50 to 60 km (31 to 37 miles) in diameter. A fourth S/2011 P1, provisionally named P4 was discovered on the 28th June and confirmed on the 3rd July 2011; and a fifth S/2012 P1, provisionally named P5, discovered on 7th July and announced on 11th July 2012; both from using ESA's WFPC3 aboard NASA's HST and managed by a team led by M Showalter of the SETI Institute.

  Pluto's orbital period is 246.04 Earth years and is highly inclined relative to the normal planetary ecliptic, being inclined at over 17° to it; and highly eccentric (elliptical). This high eccentricity (0.244) contains orbital paths that take a small region of Pluto's orbit nearer to the Sun than Neptune, and to also travel outside the orbit of Neptune at aphelion. Pluto is gravitationally bound in 2:3 mean motion resonance with Neptune, meaning that for every two orbits that Pluto makes around the Sun, Neptune makes three. This orbit has however been determined to be chaotic, in that its orbit holds stable for only a few million years, after which time general planetary and the Outer Solar System Objects perturbations introduce errors too large for reliable orbital calculations to hold; indicating that Pluto will eventually migrate away from its present orbits.

  Pluto's distance from Earth makes concise investigation of the properties of the dwarf-planet and its moons difficult. Many details about the Plutonian system will remain unknown until around 2015, when the NASA/Ames Research Centre New Horizons spacecraft, launched on the 19th January 2006, is expected to arrive in the area.
Pluto_animiert_slowed  A computer-generated surface map of Pluto (animation shown alongside) has been generated from HST images, and is synthesized to emulate the true-colour of the dwarf-planet. The actual HST observations were made in two wavelengths, which is insufficient to directly make a true-colour image. However the rendition attempts to resolve variations several hundred kilometers across and presents the highest resolutions possible with current technology.
  Observations by the HST place Pluto's density at between 1.8 and 2.1 g/cm3, suggesting its internal composition consists of roughly 50–70 percent rock and 30–50 percent ice by mass. Because decay of radioactive minerals would eventually heat the ices enough for the rock to separate from them, scientists expect that Pluto's internal structure is differentiated, with the rocky material having settled into a dense core surrounded by a mantle of ice. The diameter of the core should be around 1,700 km, 70% of Pluto's diameter. It is possible that such heating continues today, creating a subsurface ocean layer of liquid water some 100 to 180 km thick at the core–mantle boundary.
  Spectroscopic analysis of Pluto's surface reveals it to be composed of more than 98 percent nitrogen ice, with traces of methane and carbon monoxide. The face of Pluto oriented toward Charon contains more methane ice, while the opposite face contains more nitrogen and carbon monoxide ice.
 Pluto_cutaway-core_set-2_220px The existence first proposed by astronomers from the Wise Observatory in Israel in 1985; by the occasional occultation with a star, it has been detected by the Kuiper Airborne Observatory in 1988 that Pluto has a very tenuous atmosphere; with an atmospheric pressure of 0.15 pascal, roughly 1/700,000 that of Earth. The atmosphere consists of a thin envelope of nitrogen, methane, and carbon monoxide gases, which is derived from the ices frozen on the surface. Methane, a powerful greenhouse gas, creates a temperature inversion, with average temperatures 36 K warmer 10 km above the surface; however the lower atmosphere contains a higher concentration of methane than does its upper atmosphere.
  The surface temperature of Pluto ranges from a minimum of 33 K (-240 C) to maximum of 55 K (-218 C); with a mean of around 44 K (-229 C).
  Calculations indicate large seasonal variations in atmospheric content as more vapour will be present when the planet is closer to the sun, to freeze out when the dwarf-planet moves away on its elliptical orbit; and to sublimate back to some gases towards the next solar encounter. The process of sublimation was theorised to produce an anti-greenhouse effect. This proved to be part of the case in 2002 when astronomers from the Paris Observatory, using occultation, found that the atmospheric pressure had risen to an estimated 0.3 pascal, even though the planet was further from the sun. The cause was attributed to the sublimation of nitrogen from the south polar cap which had now emerged from 120 years of shadow, and was beginning to unload its ices. The second effect of sublimation was deduced in 2006 by scientists using the Submillimeter Array who discovered that Pluto's temperature was about 43 K (−230 °C), 10 K colder than would otherwise be expected at the time, indicating that the sublimation from the south polar cap was cooling the planet.
  In October 2006 the NASA/Ames Research Centre announced the spectroscopic discovery of ethane on Pluto's surface. They deduce that the ethane is produced by photolysis or radiolysis (i.e., the chemical conversion driven by sunlight and charged particles) from methane suspended in the atmosphere derived from the frozen methane on the surface.

  Charonian surface appears to be water ice and also appears to have no atmosphere. In 2007, observations by the Gemini Observatory found patches of ammonia hydrates and water crystals suggesting the presence of active cryo-geysers.
  The mass of Charon is approximately 11.65% of the mass of Pluto, with a density of 1.65 ± 0.06 g/cm3, suggesting a composition of 55 ± 5% rock to 45% ices.

The Outer Solar System
The Kupier Belt - Comets - The Oort Cloud

Ort Cloud & Kupier belt_Comparative dimensions_Astronomy Today (Adapted)_02
10 - The Kuiper belt
  The Kuiper belt, named after a pioneer in infrared and planetary astronomy Gerard Kuiper, forms a ring of planetesimals formed of icy conglomerates and terrestrial type matter, much like the asteroid belt, in an orbit just outside that of Neptune. It lies co-incident along the planetary orbital plane of the solar system. It is postulated to be the source of short-period comets; and a likely source from which the dwarf planet 134340 Pluto and its moon Charon originated. Although much of the material that makes up the belt is similar in composition to the material that comprised the accreting matter of the early solar system, it is suggested by computer models that simulate the development of the solar system that, the belt was formed from materials ejected by the Jovan planets from the inner system, during the systems formation. It is believed to be the source of the short-period (~200 year) comets.
  With the advance of new telescopes and applied electronic technologies, objects in the Kuiper belt have began to be discovered. In 1993 asteroid-sized objects were detected between 30 and 35 A.U.Kuiper_HD53143+HD139664_Dusty-disks-like-Kuiper-belt_HST_by-Audriusa-19March2006(UTC)_NASA,ESA,P.Kalas(Uni-Cal-Berkeley)_set-3_450w By 2001 some 367 objects ranging in size from 50km to 1,000 km in diameter had been detected. Estimates for objects larger than 100km in diameter exceed 100,000, with an estimated summation of mass exceeding that of the material in the asteroid belt. The Kuiper belt starts at around 35 AU from the sun and continues in depth for about another 20AU. It would thus comprise a ring of loose material of inner diameter 70AU to an outer diameter of roughly 110AU. In 2006 researchers at the University of California, Berkeley, using the HST found dusty planetary disks around some nearby stars (HD 53143 + HD 139664) that they conclude are similar conglomerates to the Sol-system Kuiper belt objects.

10 - The Oort cloud
  When investigating the source of the long period and very occasional comets that are observed to move in elliptical orbits that appear randomly displaced to the orbital plane of the planets, it was proposed that they came from a halo of debris that circle the solar system at a radial distance of some 50,000AU. No one has ever observed any comets in the faraway Oort cloud - they are just too small and dim for us to see from Earth at present The idea was first proposed in the 1950’s by the Dutch astronomer Jan Oort, after whom the proposed halo is named.
  The proposal disturbed some astronomers on account of the interpretation of the accretion model, where most of the material at these orbits should have been absorbed on accretion. These arguments have however been somewhat answered where computer models indicate that much of the material was later ejected by the Jovan planets, within about the first 2.5 billion years of the Solar systems formation. This was the peak period when most of the planets and moons were accreting, or in collision with, protoplanetary objects. The effect of these ejections has been computed to have displaced Jupiters orbit inwards by a few tenths of an AU; and caused an outward migration of Saturn by 1 AU; Uranus by 3 to 4 AU and Neptune by 7 to 10 AU.
  The number of individual objects in the Oort cloud will be in the order if millions; and the total mass estimated at around 1 tenth that of all the planets. The Oort cloud is estimated to have an inner diameter of about 50,000 AU (0.79 lt-yrs) and an outer diameter of some 100,000 AU (1.58 lt-yrs).
  A study of planetary nebulae, which give a surprising view of the construction of far solar systems, indicates that the Oort cloud hypothesis appears to have some foundation. The discovery of dusty planetary disks around some nearby stars (as noted above) provides further data for the improvement and development for accretion theory models, and strengthens the idea to search for more Scattered disk objects. Oort cloud objects, which are thought to be much smaller, and hence more difficult to detect, will need future technological advances to apply before being accepted or dismissed as a hypothesis.

10 - The Outer Solar System & Kuiper belt and Scattered disk objects
Scale: Astronomical Units (AU); 1 AU (Earth orbit) = 149.6 Meg km (92.95 Meg mi)
The Minor Planet Center Orbits (MPCORB) Database & Murray and Dermott.

  A plot of known objects detected inside the Solar System and within the Kuiper belt (epoch 2000).
  Observational bias refers to a bias in data collection that the astronomers have unintentionally applied at this time; by only looking into areas that they can more conveniently view, and in serendipitous search, rather than by conducting a co-ordinated systematic survey for such objects.
  The pronounced gap in the Kuiper belt and Scattered disk objects (shown above and below) is due to obscuration by a dark band of dust that is ingeniously apparently called the Milky Way Nigger.

  A star can generally be defined as a free standing body in space, of a glowing mass of material, in hydrostatic equilibrium; where at any point within that body, the outward pressure exerted by its internal material is in balance with the inward gravitational forces exerted by that body of material. This is a fair description, as it describes the myriad points of light which we expect to see in the sky at night, which we historically call ‘stars’; glowing bodies, that apparently do not fall apart, hardly move and hardly change; with only rarely observed exceptions.

  On the other hand, what scientists have learnt to understand about stars, is extraordinarily astonishing. That stars are objects of enormous mass, of masses beyond everyday human experience. That stars have an enormous range in sizes; but that there is a low limit and a high limit in the mass of material that can comprise a star. That stars are borne, evolve and die. That stars of different masses evolve in different ways. That stars have different colours, representing their different temperatures. That larger stars shine more brightly than smaller stars. That large stars have shorter lives than small stars. That large stars may live only 100 million years, where small stars may last 10’s or 100's of billions of years. Where some small stars that began life at the beginning of the formation of the universe, have not yet live out their lives. That small stars dim and fade away, to eventually become cold masses. That medium stars, puff-up in time, loose their outer shell of gas in extraordinarily beautiful displays, leave a hugely bright glowing ember of a star, that then slowly fades away, over 10’s of billions of years. That large stars explode as supernovae; either leaving a core as dense as the matter at the heart of an atom, a neutron star; or their core collapses to infinity, which we cannot see, but leaves a dread gravitational hole in space, a black hole, which bends space and time, and from which not even light can escape.
Stars_Comparative-sizes_Spectral-Classification-ranges-of-the_H-R-diagram_From-Morgan-Keenan_adapted-by-tobagojo@gmail.com_b500w   If that was not enough, there is indeed more to the story of stars. That there are more small stars then large stars; with an average of about 10,000 to 1, making large stars comparatively rare. That about 60% of all stars are in binary systems (2 stars orbiting together), or in higher order combinations, or of even multiple order systems. That stars can group in clusters of 100’s to 1000’s to 1,000,000’s. That stars form galaxies of 10’s of thousands to 10’s of billions of stars. That galaxies of stars form clusters, of 10’s of galaxies to 1000’s of galaxies together. When a single star goes supernovae in a galaxy, the enormous energy it releases may outshine the light of the galaxy in which it lies.
  So if that was not enough, there is still more. It is very, very improbable for stars to collide, because of the immensity of the normal distances between them. When galaxies collide, the stars move right through each other without collision; but the gravitational effects, as will be seen later, can be spectacular in the ‘starburst’ formations that follow. Closer to home however; in binary systems, the stars may be so close together that they share their outer envelops and evolve together. In slightly more separated systems, but still close, the faster evolving larger companion may loose some of its mass to its neighbour, as it expands, by streaming its expanded outer layers to the other star. The evolution of both stars is thus changed; these types of stars are generally called blue stragglers, for apart from sometimes confusing astronomers, they do not conform to the expected timescales of normally evolving stars; and its their age behaviour that gives them away. In such systems, but for a different kind of star; a companion star may get a new lease of life from its companion, but to explode as a recurrent novae each time sufficient mass from its neighbour is exchanged to it. But this can also be fatal for the star; if it happens to be of a certain size and nature, the acquisition of material from its neighbour may push its mass over a limit where, it will explode in supernovae and disintegrate entirely, leaving nothing in its place. In the congested heart of some galaxies, the traffic of stars is so dense that they do collide. The larger star thus formed then explodes to form a black hole. A number of black holes may then form. The black holes then themselves coalesce, forming a super-massive black hole at the heart of the galaxy. The mass of the black hole can equate from 100’s to 1,000,000’s of stars. The behaviour of these super-massive black holes is a study all of its own; suffice is to say that they may cause galaxies to outpour material and energy in opposing jets in orders of 5 to 10 times the radius of the galaxy itself, generating cosmic ray and visible emissions viewable across the entire extent of the known cosmos.
  Of the many curious things that have been discovered about stars, one of the most profound has been that apart from the element hydrogen, and one or two light elements that formed naturally (the primordial elements) a short time after the famous ‘big band’, at the genesis of the universe/cosmos; all the other naturally occurring elements, were made in the heart of stars; mainly the larger ones. The larger stars disperse these elements to space, forming the inter stellar medium (ISM) as it is called, as they die. The ISM is then eventually recycled into new stars. The organisms of ‘life’ use a collection of these elements; so we, living organisms on planet earth, owe our existence to stars.
  So the story of stars, ever evolving with surprises, moves on here, with least hopeful explanations and telling images.
10 - The Star Cloud in the Sagittarius arm of The Milky Way Galaxy
DSS Consortium

  The Sagittarius Star Cloud is the bright group 'cloud' in the upper centre of the view.
  The Hubble Space Telescope had a look in the centre of the Sagittarius Star Cloud to capture the view below.
10 - Sagittarius Star Cloud (SGR-I)
HST- Wide Field Planetary Camera 2 - NASA and The Hubble Heritage Team (STScI/AURA) 1998-28

  Looking into the heart of the Milky Way (MW) galaxy that lies in the Sagittarius sector, an amazing collection of stars is captured in this HST view. The centre of the MW galaxy is clouded with dust and molecular clouds of matter that obscures much of the view by normal optical telescopes; in this view the HST team chose a minute area unobstructed by the hase of dust to capture this image.
  On view is a sample of stars of all ages, some as old as the galaxy itself. Bluish stars are young O and A stars formed most recently with ages spanning 100's of millions of years. White and orange stars which make up the majority, represent stars on the 'main sequence' that have been shining for billions of years. Any tiny white stars are probably white-dwarfs; not very old because they are the final fading remnants of large mass stars that have within 100's millions of years, evolved to these dwarfs; so they may be up to about 4.5 Giga years old; but without sufficient data to determine how long they may survive brightly shining before radiating away their energy, to cool from white to red, needs furter invistigation. Large bright blue and red stars are super-giants (young and ancient respectively) blazing ferociously before the end of their lives. Small red stars are either brown-dwarfs, low mass stars (0.25 to 0.08 M-Sol say) with lives of 100's of billions of years that have as yet only lived about 1 tenth of their life-times; or fading white-dwarfs which are no longer burning nuclear fuel, but are radiating away their stored internal thermal energy to eventually becoming dark stars, the cinders of a galaxy.
Understanding Stars
The Hertzsprung–Russell (H-R) diagram
Population I + Population II stars & Metallicity


  Ubiquitous to astronomers, conceived as the most convenient way to visualise the evolutionary life of stars, individually and en-mass; the Hertzsprung–Russell diagram (H-R) displays stars in the relation of their power output (the stars real luminescence compared to the sun (Sol = 1 unit) against a plot of their measured surface temperature (degrees Kelvin).

  Binney and Merrifield astronomers and authors, whose main interests are focussed on Galactic astronomy, provide an appealing historical account on the development of the H-R diagrams and their relation to the matter of star populations; which will be related here. They note that astronomers Lindbold and Oort, who were developing theories of the kinematics (the motions) of stars in galaxies, had proposed that spiral galaxies could be better understood if they were considered as comprising two differing components that comprised the galaxy; a spheroidal group of stars and a group that made up the disk. Each of these components suggested that the stars in them were examples of two distinct stellar-type populations.
  The American astronomer Walter Baade, taking advantage of wartime (WWII - 1944) city blackouts in the Los Angeles area, using the 100 inch Mount Wilson telescope, was able to resolve stars within the inner regions (associated with the ‘halo’ or spheroidal component) of some nearby spiral galaxies; and stars from nearby elliptical galaxies. On analyses of their colour and brightness, Baade realised that these bright stars were red-giants, and quite different from the bright stars found in spiral arms, which were blue super-giants. Baade concluded that he was observing two different star populations; Population I contained the bright blue super-giants in the dusty and gaseous regions of the spiral disks; and Population II contained the red-giants in the dust free regions of spiral and elliptical galaxies. So open-clusters and spiral disks contain Population I stars and globular-clusters, galactic spheroids and elliptical galaxies contain Population II stars.
H-R_00_c_0.2+1+5+15-MSol-on-main-sequence+b-02  In the 1920’s, Ejnar Hertzsprung of Denmark and Henry Norris Russell of the U.S.A. independently discovered that if a plot was made of stars luminosity (power) against their colour (temperature), the plot began to reveal patterns of position within the diagram, and that they were not scattered randomly within it. These plots were named after their discoverers and became widely known as Hertzsprung–Russell (H-R) diagrams. Present day astronomers more usually call them colour-magnitude (C-M) diagrams in everyday use; because they use the colours they detect, or selected filtered differences, to plot directly on their graph. It is more convenient to do so; where it is inferred that the colours represent the temperature of the stars anyway. However we shall use the old H-R name, in this section, just for the moment.   Early H-R plots of stars from open-clusters and from globular clusters revealed different patterns, giving better weight to the idea of differing star populations. After much examination of the diagram, it became apparent that what was being displayed were evolutionary trends in the life cycles of stars. Between the mid 1940’s and the mid 1960’s, the emerging technology of computers began to have a strong impact on the understanding of stars, as mathematical modelling began to bring convergence between theories and observations. Further application of reverse-engineering, by use of proposed theoretical models of star composition and age, plotted on the H-R diagram, began to reveal what these groupings represented. And so the dual tools of observation and theoretical modelling, after years of effort, brought an understanding of the evolutionary life cycle of stars. So the H-R diagram became a convenient way to visualise, or plot, a stars life; as it progressed through millions or billions of years of its evolutionary life-cycle, from birth to death.
  The principal strength of the H-R diagram is its ability to display, at a glance, the similarities and differences between different types and groups of stars observed. The principle feature of the H-R diagram is its location of the Main Sequence (MS) stars. Main Sequence stars are those that have evolved to the point of just starting their nuclear ‘burning’. They have just changed from being a mass of hot glowing gas, to a true nuclear fired ‘star’. This is the point at which the star has started to burn (fuse) hydrogen into helium in their cores by thermonuclear synthesis.
H-R_00_g_protostar_on-Hayashi%20track_to_main-sequence_adapted_astronomy-today+b_02   After accretion, a star will shine under the influence of gravitational compression, moving along what is now called the Hayashi track (see later) at the end of which it starts thermonuclear ignition to become a main sequence star; and then later moves away from the main sequence, to evolve into different types of star.
  The H-R diagram displays the main sequence trend as a curved band that is heavily dependant on the original mass of the young MS stars. This band is sometimes called the ‘Zero Age Main Sequence’, or ZAMS plot, and positions the stars according to increasing mass. The relation that has been found is that; low mass stars reside at the bottom; and high mass stars at the top of the MS plot. All further analysis then follows, by comparison of where a star, or a group of stars, may lie in relation to the MS plot.
  From these relationships, the type of star, its age, the age of a group or cluster of stars, and other features of interest may be determined.
  It was through these H-R plots that it was discovered that stars from open clusters represented young stars, of Population I; and that globular clusters represent old mature and dyeing stars, of Population II.
  It is not a trivial exercise to place a star on the H-R diagram, as a star needs careful analyses of its characteristics before being plotted. The H-R diagram requires an accurate determination of a stars power output, or luminosity as astronomers prefer to term it; a characteristic which is related to a stars surface temperature (colour) and its size. But as it is not easily practical to measure a stars size directly, this will be inferred from the stars temperature; by using bands of different frequencies (colours) and measurements of their intensity; and that relationship is calibrated from the known black-body radiation plots specific to a particular temperature. This colour relation ( hence colour-magnitude (C-M) ) however still needs to be referred to a standard to have any comparative meaning; so the standard chosen is the luminosity of our local star, the sun (LSol=1). An accurate order of the stars distance is also required for the calculations, this can be pains taking to do. Once determined however, stars thus plotted on the H-R diagram may then be given a classification number that denotes, at a glance, the type (colour; size) and inferred age of the star.
  When clusters of star are analysed and plotted on an H-R diagram, the age of the cluster may then be determined from examination of the resultant placing and grouping of the stars on the diagram. Where it is assumed that all stars in the cluster were accreted at around the same time; the stars of the group would each have then evolved in a way characteristic to their starting mass. The maturity of the population now viewed, will display their current evolutionary status on the H-R diagram, from which the age of the population can de determined by examination of the point along the MS where the stars are just old enough to initiate helium burning, to start to ‘turn off’, away from the MS. At the ‘turn off’ point, the spectral class of the stars at the tip of the turn is determined; as we already know at what age that spectral class of star will begin to start helium burning, the age of the whole cluster will then follow as that age.

  Where it has earlier been indicated that stars form from generally two different populations; Population I for young stars and Population II for old stars; the significance of the differences in population has now been found to be related to a parameter termed the metallicity of the stars. In a slightly confusing legacy leftover term from historical astronomy; it is the Population II stars that are actually the first type of stars to have been formed. The theory postulates that they were formed from primordial hydrogen and helium, that was the first of a small number of the light elements to precipitate out, between 2 and 17 minutes after the Big Bang creation of the universe. As the universe cooled further after the event, ionised then molecular atoms froze out of the primordial particle soup to represent a significant amount of the matter-nuclei of the universe. The abundance of dark-matter that was also precipitated, presumably at the same time, is outside of our scope of concern for this discussion; is not well understood and remains an area of active research. This era of primordial nucleosynthesis, marks a period known as the atomic epoch. This era is theorised to have been followed, roughly over the next billion years, by an era termed the galactic epoch. It was in this period that the first stars were formed in galactic conglomerates, originating the Population II stars of low metallicity, comprising mostly of hydrogen and helium. These stars would then evolve and die (not all, some of the lower mass variety are still evolving today) to have performed further nucleosynthesis of the heavier elements in and around their cores, from which astronomers have another legacy habit to call anything heavier than helium ‘metals’. These ‘metals’ roughly represent some 90 elements, Lithium-3 to Uranium-92, that are the ‘natural’ elements noted in the periodic table of elements. (We recall that any element of number 93 and above; are man-made). Any second or further generation (n-th) stars born out of debris of these first generation stars, now become Population I stars of higher metallicity. Again, our local star, the sun, is used as a benchmark of a star with medium metallicity; having been made from material of the n-th generation of stars formed in the disk of the Milky Way galaxy. Stars of similar type, but of higher metallicity, are noted to have spectra shifted slightly more towards the red than low metallicity stars.

CAUTION: Just a mild caution that in the H-R diagrams shown here, the tracks shown for star evolution are somewhat simplified in representation, as real stars and their currently understood models, are actually a little more complex in behaviour.


Main Sequence Mass (Sol = 1M) -- : -- : -- Star evolution by Mass -- : -- : -- Star Type Classification (Sol = G2V)


Famous local Stars -- : -- : -- Nearby local Stars -- : -- : -- Brightest (most luminous) local Stars


The hypothetical evolution, over 10 Giga years, of a star cluster illustrated on the H-R diagram

Star Cluster Evolution
On the assumption that all stars are accreted at about the same time

Time -Years


100 x 103 Larger stars O to F arrive at the main Sequence; with the smaller mass stars still in the proto-stellar stage.
10 x 106 O and B’s already burning (fusing) helium to carbon in cores; G’s begin to arrive at MS.
100 x 106 O and A Super Giants now moved to multiple shell-burning and nearing end of life as supernovae; A stars go to helium burning begin to peel off MS; K stars join MS.
1 x 109 O and B stars exploded and gone; A stars move on to multiple shell-burning and some in Red Giant stage; some higher mass stars in Planetary Nebulae phase, with a few beyond as white dwarfs; last of the K’s settle into the MS.
10 x 109 Fully evolved star mixture; most A gone to white dwarfs; F stars in various stages of Planetary Nebulae, Super Giants, Horizontal branch variables, Red Giants; G stars begin to leave MS, marking the age of the cluster as 10 Giga years at the 'turn off' point; M stars just about on the MS to remain there for a further 10’s of Giga years.


Plot of globular clusters (like M80 @ 8kpc) -- : -- : -- 1M-Sol Full Track (life-cycle) -- : -- : -- Hipparcos (Space Telescope) Data

Blue Stragglers (from left H-R plot) are stars who's evolutionary life has been altered by acquiring/loosing mass in a close or contact binary environment,
thus altering their evolutionary track as expected for the age of the population of stars under investigation.
The main point being made here is that the 'turn-off' location, the point at which the main group of stars branch away from the main sequence
signifies the age of the star cluster, which here is about mid-way between F and G type stars,
shows an age for the cluster of around 4 to 5 Giga years.

Note: Hipparcos (High Precision Parallax Collecting Satellite) a tortured attempt to honor the ancient Greek astronomer Hipparchus of Nicea, who made the first known star map; a mission by the European Space Agency (ESA) 1989 to 1993. A reduced data set from 20,000 data points of stars within ~200 pc (652 lt-yrs) provides one of the most precise H–R diagrams ever compiled.
The Hipparcos parallax data was about 10 times more accurate than ground based data, at the date of its release in around 1999. The satellite also measured star colours, which transulates to tempreature. The Hipparcos data became the benchmark for distance measurements, and caused a recalibration of most other measuring techniques; and literally, changed the percieved size of the universe. Among other ramifications of its data, and considered by some to be its most significant contributions to astronomy; it recalibrated the Cepheid variables, placed the Large Magellanic Cloud 10% further away; increased the distance of the Andromeda Galaxy by 33%; indicated that the oldest stars are a little younger than was previously thought and reconcilled the embarrassing problem that some stars seemed to be older than the universe itself.

The data set is truncated for low mass stars (bottom of plot), the red dwarfs (failed stars) and brown dwarfs (dead stars), because they were to faint for the electronics to detect.

Adapted from Astronomy Today
Young and Old stars in Andromeda's halo - HST NASA ESA TA Brown_02b_990w
Stars - Position in Andromediea 10 - Stars - Young and Old stars in Andromeda's halo

  The stars in the upper HST image are a selected view represented by the field outlined in the angled box of the image to the right, noted as ‘Starfield’. The image selectively samples the stars that make up a global ‘halo’, roughly a ball of loose stars that are part of, and that surround the Andromeda galaxy, M31. A small handful of bright closer local Milky Way galaxy stars, pollute the main image. Pleasantly, a globular cluster of the halo, is also captured at the right of the image (a cluster of bright white stars).
  The intent of the image was to capture a sample of stars out of this halo; Andromeda being the closest ‘regular’ galaxy to us, and its halo stars being just resolvable by modern day telescopes. Other ‘regular’ galaxies are just too far away, for their stars to be resolved, for this sort of investigation.
  Stars with striations (mainly the brighter ones) are most likely pollution of the image by stars, closer to us from our own Milky Way galaxy; where the striations are optical artefacts due to the telescopes mounting hardware.
  Variously scattered are obvious galaxies lying in the background field. But of the stars; the younger ones are most likely blueish and the older ones red. All that can really be said, is that their won’t be many young stars, as the halo formed when the galaxy itself formed, so they are as old as the galaxy itself; so blue giants will be a bit scarce; they die quickly.
  However there will be stars in the halo left over from any interactions the galaxy has had from more recent collisions and absorptions with other galaxies in the past, which generates new stars. There will be stars that have been ejected into the halo from these gravitational disturbances. Most stars will be main sequence stars, of various sizes, and then the older red giants of aging main sequence stars; and their leftover pieces, fading small white dwarfs.
  Whatever they are, they are magnificent.


  In the main, there are about 5 different processes in principal, by which stars are borne; all of which have the prerequisite of sufficient an accumulation of gas and/or molecular dust from which the process of star formation can start.
  Leaving aside for the moment the convoluted detail of arguments arising for the formation of stars into galaxies, from the early cosmological standpoint of a uniform background of matter, that then needs to become clumpy and grainy, in large probability chunks, before it can coalesce into galaxies of stars; we look instead first at other, the more violent of the processes, to begin. As even though the process of primordial galaxy formation is of high and important interest, it will be noted later; however understanding the fundamental processes of single star accretion, is a sub-set and prerequisite for any grand model.

  A tangible view on some of these processes has only relatively recently been available to astronomers and astrophysicists within the last three decades or so; as a plethora of now space borne and new technology ground instruments, probing the universe in virtually all areas of the electromagnetic spectrum, have worked together to provide the observational data, the likes and quality of which has never before been so astutely managed nor so widely accessible. And together with this, among many technologies, the advances in electronic control and computer hardware and software technologies that have enabled data acquisition (e.g. imaging), data storage (e.g. memory), data transport (e.g. telecommunications) and data manipulation (e.g. mathematical modelling) to progress to star-formation_The_Southern_Milky_Way_Above_ALMA_720wstaggering levels of sophistication and application.
  The details of the fundamental process that occur to actually form a star, are still not fully understood and are in a continual process of review. Astrophysicists attempting to model these processes, assisted by data from observational astronomers, face many complex challenges in producing a diverse array of models to illustrate the characteristic birth of a single star, or for the formation of clusters of stars, and so on.

The Southern Milky Way above Atacama Large Millimeter/submillimeter 66 antennas Array (ALMA); The Chajnantor plateau
@ 5,000 m (16,400 ft), Atacama, Chile. Republic of Chile; ESO; National Radio Astronomy Observatory (NRAO); National Astronomical Observatory of Japan (NAOJ).
By ESO; Babak Tafreshi - TWAN
28 May 2012
ALMA went fully On-Line on 13 March 2013

  Models must face the observational realisation that not all stars are single enteritis, but that around 60% of all stars are binaries, or of associations of a higher order of complexity. That clusters of stars may be closed (remain gravitationally bound), or open (loose gravitational focus). That some stars are primordial (1st generation, as old as the universe itself, and formed from the primordial constituents of matter) and others are of nth generation (formed from material processed in previous generations of stars), thereby being made of material containing ‘metals’, elements produced in the interior of previous generations of stars; so these models should also contain parameters for ‘metallicity’. That on the micro scale, the model should account for the formation of stars and planetary systems; on the small scale, account for the formation of star clusters; on the medium scale, account for the formation of oval and spiral galaxies and their interactions; and on the large scale account for the formation of galactic clusters; and on the cosmological scale, to account for everything contained within what is understood to be the known universe.
  A tall order indeed.

10 - Barnard 3 - IRAS Ring G159.6-18.5
The Wreath Nebulae centered on star HD 278942

Wide-field Infra-red Survey Explorer (WISE) 28 Dec 2011
NASA; JPL-Caltech; UCLA; JDsgat
Blue and cyan (blue-green) 3.4 & 4.6 microns; predominantly from stars
Green and red 12 & 22 microns; mostly emitted from dust.

  It turns out that a cloud of gas and/or molecular dust from which a protostar is to form does not at first easily congeal; as electrostatic and magnetic coupling, within the cloud of matter, tends to oppose any form of collapse. It requires wide ranging perturbations in order to influence the large amounts of tenuous matter that is required, to begin congealing. Radiation, mechanical shock, gravitational shock or attraction, are the main perturbing influences, as will be shown.

  From the far end; the most violent, and on a large scale, the first scenario operates when galaxies interact or collide. Overwhelming the comparative sedate processes within lone galaxies, interactive gravitational waves shock the mixing galactic materials of gasses and molecular dust clouds in turbulent wave motion. The result is the ‘starburst’ production of massive O and F type star-clusters, along the advancing wave fronts, within the galaxies.

  The second most violent, but now on a comparatively microscopic scale as far as a galaxy is concerned, are the perturbations due to supernovae explosions. The outburst can stimulate a chain reaction of star formation from nearby or surrounding inter-stellar material, where star propagation moves outward, or around the supernovae disturbance. Our home, the local Sol-system, is deemed to have been initiated by this type of process.

  The third process is most easily observed at the edges of some molecular clouds where large O and/or F type stars have formed near a molecular cloud; and their intense outflow of gamma radiation disturbs the cloud into star formation. This then evolves into a dual process; where the radiation then progressively eats into, and consumes the cloud; sporning stars of various sizes along the way; stars which may themselves then evolve into supernova, thus having the previous effect described.
  The radiation process however poses a counterproductive threat to star formation, in that the outflow of gamma radiation from these large stars may be so intense, that they actually strip away accreting material from newly forming stars within and around the cloud, stunting their growth.

  With far less violence, the fourth process is the sedate movement of the rotating progressive gravity and compressive waves that stimulates the formation of stars, that sustains the stars in the arms of a spiral, within the disk of spiral galaxies.

  Finally, the fifth is the more difficult as well as being the more fundamental of all the processes. This is by random perturbations of gravity, which stimulates the material in a cloud of gas and/or matter to begin gravitational collapse. Within large clouds, inequalities of disturbance may cause the cloud to become clumpy, thus simultaneously forming the nucleus of many star sites. It is the behaviour of a single cloud of material, that is of interest here.
protostars_Barnard3_IRAS-Ring_G159.6-18.5_Wreath Nebula_WISE-28Dec2011-Infra-red_NASA,JPL-Caltech,UCLA,JDsgat_500w
The nebulae - Bernard 3 - centres around the white star, HD 278942, immersed in a red cloud of dust that is probably more metallic than the surrounding regions. It glows red in re-emitted emissions driven by the ultra-violet energy emanating from the young star. A star formed from the material of the nebulae around it, warmer gas and dust that shows a green tint. But the star is now clearing a hole in it, by its own emissions and stellar winds; creating the characteristic wreath shape.
Two smaller white stars, to the left and far left respectively, are beginning to clear their own areas within more dense dusty cocoons, slightly cooler, seen as yellow-brown rings.
The green ring is made of tiny particles of warm dust whose composition is very similar to smog.
The bluish-white stars scattered throughout the image, are forward and rear polluting stars in the visual field of the nebulae.
Nebulae - Gas, Molecular Clouds & Dust – Matter & Nurseries for Stars

Orion the constellation taken by astronomer Akira Fujii_2_990w
10 - Orion the Constellation
Pictured by astronomer Akira Fujii - Asterism and annotations by author.

10 - Star Betelgeuse - Alpha Orionis - A Red Supergiant
HST 3 March 1995 - Ultra-violet Faint Object Camera; NASA ESA Andrea Dupree (Harvard-Smithsonian CfA), Ronald Gilliland (STScI)

  Betelgeuse is famous for being one of the closest and largest of the red supergiants. With a radius some 630 times larger than the sun, if placed in our solar system its photosphere would lie at ~2.93 AU (ie Earth orbital radii), right on the outer edge of the Asteroid belt. Its photosphere is however cooler than that of the sun at ~ 3,000 K; but the white area of the image is believed to be an unusual persistent flare or storm on the surface with a temperature of ~ 5,000 K.

Asterism of Orion by Uranometria di Bayer (Right)


M42-The Great Nebula in Orion_Sketch by the Earl of Rosse_(scan)_Cassel&CoLtd_Lith_London_1890_r-90_990w_set2
10 - M42 - The Great Nebulae in Orion; a Sketch by the Earl of Rosse (William Parsons) (~ 1845 to 1850); Messrs De la Rue; Cassel & Co Ltd, Lith, London 1890 (scanned image)

The Rosse instrument, the Leviathan of Parsonstown as it was locally called and for credence to the worlds largest optical telescope of its day, is a Newtonian 6ft (72 inch) (1.83 m) brass reflector;
(66% Cu + 33% Sn) of 3 tons ~1845 to 1908.
Birr Castle, Parsonstown, Ireland

Its predecessor, the original Rosse instrument, was a 3ft (36 inch) (0.91 m) brass reflector; 1826 ~ 1845.

M42 The reflection Nebula in Orion_Anglo-Australian Observatory by David Malin_hs-2002-05-c-large_web_990
10 - M42 The reflection Nebulae in Orion or The Great Nebulae in Orion
Anglo-Australian Observatory by David Malin

  Here we come upon the M designation, a catalogue of objects devised and compiled by an eighteenth-century French astronomer named Charles Messier. It is noted that Messier devised his catalogue to list objects that should not be confused with comets, his main field of interest. However today we are more grateful for his list of 109 ‘Messier Objects’, considering his catalogue a far more significant contribution to astronomy then his original work on comets.

  The Trapesium cluster of young bright O-type stars (See below) is mainly responcible for illuminatine the molecular dust (mainly red) and gasses (mainly blue and bright) seen by reflection in the central part of the image.
10 - M42 The reflection Nebulae in Orion or The Great Nebulae in Orion. Dust areas enhanced by image post-processing Igor Chekalin
La Silla 2.2m MPG/ESO telescope; Camera: WFI 8k x 8k mosaic CCD; 2-3 Jan 2005; ESO, Post-processing Igor Chekalin; on Flicker

  Post-processing signifantly enhancing the contrast between the molecular dust (red) and gas (blue). Light scatter by the dust particles causes the reflected light to return red; while ionised hydrogen is excited by the incident ultra-violet to be re-emitted at lower frequencies, providing a blue glow.
M78_Location-in-Orion10 - M78 - NGC 2068 - A reflection Nebula in Orion @ 1,400 Lt-yr (429 pc) distant.
La Silla 2.2m MPG/ESO telescope; Camera: WFI 8k x 8k mosaic CCD;
Filters: blue, yellow/green and red.
ESO, Post-processing Igor Chekalin, 11th November 2010

The location of M78 relative to the constellation of Orion (right).

  Demonstrating the beauty of the re-emitted blue haze from excited Hydrogen II regions that make up a reflection nebulae, M78 or NGC 2068 comprises the central large glowing region of gasses in this image.
  The reflections are excited by the intense ultra-violet radiated by the nearby associated young O,B-type blue giants. As can be seen, these radiations impinge on the surrounding molecular dust and gas clouds, forming cleared pockets within them.
M78_sub_NGC2064_McNeil's Nebula+V1647-Ori  The upper nebulae to the left shows a group of young stars in a bubble of hot gas, through which they shine, slowly clearing a cocoon of dust; this nebulae is designated NGC 1971 & NGC 2071.
M78_sub_other  The top of the dumb-bell shaped glowing nebulae, over the right side of the main nebulae, is NGC 2067; and the largest and brightest glowing filament below the dumb-bell, is NGC 2064 (left), a recently discovered variable called McNeil's Nebula. Within the nebula, the variable V1647-Orianus, is believed to be a young low mass star, with unusual bi-polar emanations. These emanations are believed to be associated with intense magnetic fields, much like but more intense than those we observe in sun-spots, and which are accelerating ionised particles at these poles sufficiently fast to generate frequencies as high as soft X-rays. The non-axial alignment of these bi-polar regions to the stars spin axis, produces the ~ 1 day variability observed for the system (NASA, 2003).
  The lowest cross-shaped nebulosity on the right-bottom, with a yellow hew, emanating through a very dark background of dust (right), is another region of recent star birth.
Star Birth and Stars

M42 - NCG1977 The Great Nebula in Orion (reflection)_01
10 - M42 - NCG 1977 The Great Nebulae in Orion, a reflection nebulae.
HST - NASA, ESA, M Robberto (STScI)

  A little to the left of the upper centre of the image, over the creamy white reflections from the dust and molecular clouds of the background nebulae, are a group of stars (pink) called the Trapesium cluster. The intense radiation they produce causes the nebulae to shine, and is also disturbing the nebulae material around them to coaless into new stars. Their emmisions are so harsh, that some of the nearby protostars that they have encouraged into existance may have their potential planetary discs destroyed before the younger stars are able to mature into planetary systems. The young stars will remain however, but their grouth stilted, as the matter from their acreation disce is blown away.
NGC1976 nursary of young stars in the Orion Nebula M42_HST WFPC2 2002 by CR O'Dell (Vanderbilt)_hs-2002-05-d-full_990w
10 - NGC 1976 a nursary of young stars in the Orion Nebulae M42
HST WFPC2 2002 by CR O'Dell (Vanderbilt)

  It is the intensity of the ultra-violet radiation shining from the bright young stars (pink) in the foreground, that is responsible for the bright glow of the re-radiated emissions of the M42 nebulae behind. The tight group of stars (pink) on the upper-central are called the Trapezium cluster, which are O-Type blue super-giants. They were first discovered by Galileo Galilei with his small telescope with which he was just able to distinguish 3 stars of the group, which he noted in a sketch on 4th February 1617. The Trapezium cluster, so named because of the geometry of its brightest components, had been resolved into 8 principal component stars by 1888.
   The Trapezium cluster of super-giants is estimated to occupy a spheroid of 1.5 light years in diameter. The cluster is considered to be a sub-group of the Orion Nebulae cluster which comprises around 2,000 O-Type stars occupying a spheroid of some 20 light years in diameter.
   The 5 largest O-Type blue super-giants of The Trapezium cluster are estimated to mass 15 to 30 times Sol, luminosity 1k to 5k Sol, surface temperature 12k to 18k deg Kelvin, and quite young at around 300k years old; with a life expectancy of about another 10 Meg years. Their large masses cause their internal core temperatures and pressures to be so high that they burn their nuclear fuel very rapidly and thus have a short life span. They represent a very rear group of stars being only about 0.3% to 0.8% as numerous as all other types of star, as measured from a sample made in our local region.
M42 - NCG1977 The Great Nebula in Orion (reflection) HST_infra-red+other filters showing young stars hidden within the nebula_close detail_02
10 - M42 - NCG 1977 The Great Nebulae in Orion. Showing closer detail, of young stars hidden within the nebulae. Many of the small stars are believed to be failed stars of very low mass, known as brown-dwarfs, as they appear dim in the infra-red.
HST Infra-red + other filters - NASA, JPL-Caltech; T Megeath (University of Toledo), M Robberto (STScI)


  Protostars, which we understand today to take roughly 10’s of millions of years to evolve out of the gravitationally bound matter of the gas and dust clouds from which they are formed, begin to glow within about the last 100,000 years of their accretion. They glow dissipating the gravitational energy of formation as their gas is heated by the compression of collapse. This is called the Kelvin–Helmholtz contraction phase, named after Lord Kelvin (William Thomson - 1862) and Hermann von Helmholtz (1856), both European physicists.
  The earlier understanding of Kelvin and von Helmholtz, which was initially focussed on reconciling some correlation between geophysical evidence and the age of the Earth, and by default the age of the Sun, proved to be around two orders of magnitude too low to provide the amount of energy required for a system that was then beginning to be scientifically establish at an astonishing age of over 1 Gig years; an age we now understand today to be of the order of just under 5 Gig years.
  This alarming deficit in energy would take a further 80 years before a reasonable explanation for both source and method were to be discovered. Nuclear energy provided the source and thermonuclear reactions the method.
  The gravitational collapse of a single cloud of material, to produce a protostar, was considered by the British physicist Sir James Jeans (1877 – 1946) who, using parameters of particle density and temperature, derived a formulae for calculating some minimal mass of material that would in all probability collapse gravitationally. This critical mass is known as the Jeans Mass.

  Resisting the collapse of a cloud of molecular gas and dust is a pervasive magnetic field coupling with ionised material within the cloud. In a process not fully understood; at sites sufficiently gravitationally disturbed within the cloud, the magnetic coupling is weakened, and the material congeals to become more dense. The magnetic energy is first dissipated as low frequency radiation (low infra-red) that can easily leave the cloud. The collapse of the cloud then proceeds relatively rapidly due to the inherent radiative transparency of the cloud, but kinetic interaction within the cloud causes the temperature to rise from the low base of the inter-stellar medium (ISM) ~3 K, to a comparatively low 10 K to 20 K. Material concentrated now in the forming core; the core becomes opaque to radiation and the temperature begins to rise to about 2,000 K; at which point molecular hydrogen dissociates into atomic hydrogen.
  The dissociation of the hydrogen causes an energy sink, promoting another free-fall collapse of the cloud, in which the atomic hydrogen also now begins to ionise. The dissociated electrons now begin to absorb the radiative energy causing convective cells to be established to remove the gravitationally induced energy from the central core, to its outer regions. The temperature of the protostar however continues to rise, over time, to millions of degrees K.

  A measure of hydrostatic equilibrium results between the gravitational collapse and the temperature induced pressures, and the rate of collapse of the cloud is markedly slowed. The convective volume now begins to shine; the protostars joins the Hayashi track on the H-R diagram; so named after C. Hayashi, a Japanese astrophysicist, who did investigative and definitive work in the 1960s on the evolution of pre-main-sequence stars. Hayashi is cited to have actually developed the behavioural model of fully convective energy transport for protostars, that is used today.

  The collapse of the protostar now proceeds at a much slower pace. Apart from dissipating gravitational energy, the star shines by fusing low mass elements, like deuterium and lithium within its convective cells, but is not sufficiently hot to fuse hydrogen into helium. One of the things that Hayashi discovered was that; once the protostar became fully convective, its luminosity becomes nearly independent of its temperature at that stage, but is mainly dependant and proportional to its proto-stellar mass. Also, for a time, protostars glow brightly, and even more so, than Main Sequence (MS) stars of equivalent mass; as in general, they fall from higher luminosity, to join the MS below.

  The future progress of the protostar is now governed by the total effective mass of its accumulate core.
The positions reached by stars after 1, 10, and 100 Meg yr from birth are marked with dots.
Left panel: The evolution of stars massive enough to burn H on the MS before they reach the MS. Each curve is labeled with the object’s mass in solar units. At first these objects are fully convective and descend almost vertically along the Hayashi track. Stars with masses M (approx) ≥ 0.3 MSol eventually cease to be fully convective and move sharply leftwards towards the ZAMS.
Right panel: The equivalent figure for low-mass objects. At first the descent of these objects is slowed by the combustion of Li and D. Once an object has exhausted its D, it moves more rapidly towards lower temperatures and luminosities.
[From data published in D’Antona & Mazzitelli (1994)]. Ref: Binney + Merrifield (1998) Galectic Astronomy; pg282.
  The following notes relate to the H-R diagram above.

  Protostars of mass ≤ 0.08 MSol, insufficiently massive to attain hydrogen to helium fusion, once they have consumed the light elements D and Li, loose luminosity to fade from being brown-dwarfs, to black-dwarfs, within an order of 100 million years.

  Protostars in the mass interval, 0.08 MSol to ~ 0.3 MSol, are also insufficiently massive to attain hydrogen to helium fusion, settle to the bottom of the Main Sequence (MS) being fully convective. They maintain the same order of temperature at which they started, but slowly loose luminosity; to make a near vertically falling trace on the H-R diagram. By the time they have arrived at the bottom of what is observationally defined as the MS, they will have run out of fuel and gravitational energy to remain truly luminous. The larger mass protostars having attained a temperature of just under 10,000,000 K, before beginning to fade away from being brown-dwarfs to become black dwarfs; again within an order of 100 million years.

  Protostars of mass > about 0.3 MSol eventually attain a temperature over 10,000 K, sufficient to attain the p-p hydrogen to helium fusion chain reaction within the high pressure regions of their core; because of which, they now classify as red-dwarfs. At this point, radiative transport begins to differentiate a fusing core from a convective shell. There is a rise in temperature, but the luminosity only increases marginally as the star continues to contract. Because of the rise in temperature, the protostars takes a move to the left of the H-R diagram. Following a period to the order of millions of years to attain new dynamic balance between core power and convective shell transport, the protostars expand slightly, dropping in luminosity, and settles on the MS to maintain core hydrogen fusion, as Zero Age MS (ZAMS) stars, until such time that their fuel runs out. This is represented as a small down-turn to the right, on the H-R diagram.
  This mass range of stars is insufficient for them to progress further than the fusion of the light element hydrogen into helium. Unable to progress to helium fusion, and because of the comparatively low rate of energy conversion when compared with higher mass stars, these stars can remain as red-dwarfs on the MS for a few billion years before fading to brown, then black-dwarfs, when their hydrogen fuel runs out.

  Protostars of mass > about 0.7 to 0.8 MSol evolve in a more complex way and end their lives as quite different types of stars.
Bok_globules_in_IC2944_HST_WFPC2,acq-Feb1999+Feb2001,rel3Jan2002_NASA+HHT(STScI,AURA)_Bo-Reipurth(Uni-of-Hawaii)_set-02_495w Bok_globules_+_molecular-clouds_in_LH95-stellar-nursery-in-LMC_HST-19Dec2006_NASA,ESA_HHT(STScI,AURA)+HubbleCollaboration_set-02_495w
  The theories of stellar formation from clouds of molecular material were originally investigated by the British physicist Sir James Jeans (1877 – 1946), but to put the theories to test, astronomers needed to find examples of the processes in action. In the early 1940’s the American astronomer Bart J. Bok, from the University of Arizona, began surveys of dark cloudy objects in reflective nebula. In March 1947, in a paper presented together with Edith F. Reilly, Bok proposed that the clouds that were being investigated were gravitationally accumulated material that were forming cocoons in which star formation was in progress. Over the intervening years, these objects gained the designation ‘Bok globules’ and have proved, with the use of infra-red and radio telescopic investigations, to contain proto-stellar nuclei.
10 - Bok globules in IC 2944
HST WFPC2; acquisition Feb 1999 + Feb 2001, release 3rd Jan 2002; NASA and The Hubble Heritage Team (STScI, AURA); Bo Reipurth (University of Hawaii)
10 - Bok globules & molecular clouds in LH 95, a stellar nursery in the Large Magellanic Cloud
HST 19 December 2006; NASA, ESA, and the Hubble Heritage Team (STScI, AURA) + The Hubble Collaboration
Herbig-Haro Objects

  Herbig-Haro Objects are a sub-class of stellar objects associated with young protostars. In honour of two astronomers who did much of the early work on protostars in the 1950’s, George Herbig and Guillermo Haro, a catalogue designation HH has been devised to classify these class of objects.    The main features that classify HH objects is the phenomenon of bi-polar outflow. The conjecture is that these are examples of the birth of stars. Still not fully understood, these objects are being studied to improve our understanding and help develop theoretical models of star formation. These studies suggest that at the critical point of star ignition, the onset of nuclear fusion that begins to burn hydrogen into helium, the star develops jets of material that is squirted out from its poles, along the axes of rotation, simultaneously in both directions; hence bi-polar.
   A proposed model that explains the phenomenon is as follows. The material that is accreting on the growing protostar will carry some charge, which it carries to the protostar. There are also residual magnetic fields from the collapsing material that will be collected to reluctantly follow the shape of the collapsed accretion disk forming around the protostar. The protostar now heating by kinetic gravitational collapse has, as discussed before, begun to radiate its internal heat by convective transport. Together with the charged particles falling on it, and the high state of ionization within its own material, there is a very large circulating electric current within the star, which promotes a dynamo effect. The electric fields generate their own magnetic fields, which interact and couple with any other magnetic fields in the vicinity.
hh_cloud-(boc-gobule)+disk+protostar+jets_artistic-impression_500w   By the laws of conservation of momentum (like a spinning ice-skater bringing in their arms), the in-falling material from the disk imparts a turning moment on the star, around an axis perpendicular to the accretion disk. So the protostar itself is spinning more rapidly than the outer parts of the accretion disk. Similar to the Babcock Model that describes the entrapment and wrapping of magnetic fields around the sun, to ultimately generate sun spots; the magnetic fields around the protostar get locked into the circulating convective cells of the protostar, rapidly twisting them around the axis of rotation. The protostar, in the unusual state of having a very large convective mass to core ratio, and thus very deep convective cells, will have very compact and twisted magnetic fields emanating at its rotational poles. These fields will attract ionised material to spiral around them, ejecting the material as jets along the axis of the poles. These jets fiercely propel material away from the star, where it can be detected interacting with the interstellar medium around the star.

An artists impression (left) of a protostar forming within the dark molecular cloud of a Bock Gobule

   What results are the features that define these HH objects. Where the interstellar medium is of low density in matter, just long jets of ejected material are observed. As there is always some matter in the medium, thin wisps of material develop at the ends of the jets as the material slows down. The more dense the interstellar material, shock fronts develop, slowing the material into thin umbrellas of material around the ends of the jets. If the interstellar material is very dense, the star develops inside an elongated cocoon of ejected material. If there are intense radiative sources like the O-Type blue super-giants in the vicinity of these new stars, as observed in the star nurseries of the Great Nebulae of Orion; the cocoons are exposed as the surrounding medium is cleared away. In these specific cases, the protostars may be stunted in growth as the incident radiation may strip away their accretion material.
   Astrophysicists are still coming to grips with the complexity of these phenomenon. An understanding maintains that, in the absence of severely disturbing external influences (like O-Type stars), as the young star develops beyond the HH phase, its own radiation begins to clear its surroundings; ionised material around the star decreases; the star internal organisation increases; the intense magnetic fields lesson; the bi-polar outflow subsides. The accretion disk around the star is slowly cleared of dust by its solar wind and by planetary accretion, and a new solar system slowly emerges.

   A footnote to bi-polar outflow is that similar outflows are observed from the centres of newly formed spiral galaxies; and out-flowing from spinning neutron stars and black holes. But the phenomenon here is due to magnetic and gravitational fields many orders of magnitude larger, and the processes more intensely violent, than for the formation of a star. They are also more associated with star-death than with star-birth. These jets comprise matter moved to relativistic velocities and involve interactions of matter that generate x-ray and cosmic-rays observable over intergalactic distances.
hh30_side-1_r1  hh30hh34hh47
10 - (HH) Herbig-Haro Objects: HH30 + HH34 + HH47
HH34 Protostar in Orion - VLT Kueyen + FORS2 ESO 17 November 1999
10 - HH34 Protostar in Orion
VLT (Kueyen) + FORS2 17 November 1999; ESO

M42 a nursary for protoplantes in the Nebula of Orion - HST 1995_hs-1995-49-b2-full_990w
10 - Deeper into M42 of Orion, to the left of the Trapezium cluster, a nursary for protoplanets is found.
HST 1995 - NASA, CR O'Dell Rice University

M42 - A protoplanetary cocoon and protoplanetary disc in the Great Nebula of Orion_HST 1995_990w
10 - M42 - View of a protoplanetary cocoon and protoplanetary disc (black) blown by strong winds of particles and radiation from nearby maturing stars in the Great Nebulae of Orion
HST 1995 - NASA, CR O'Dell Rice University

10 - Sh2-106 or S106IR protostar in Cygnus (The Swan) (Below)
HST 17 December 2011; Filter: Hydrogen = blue – NASA, ESA; JDsgat

  Within this compact star forming region in the constellation Cygnus, newly-formed star Sh2-106 is virtually shrouded in dust at the centre of the hourglass bi-polar feature. Remnants of an accretion disk show brown around the waist of the hourglass, while bi-polar outflow of ionised hydrogen shows as bright turbulent blue wisps.
  Sh2-106 appears to be in its latter stages of formation; appearing now to be in the process of clearing the volume around it of accreted gas and dust.
  The original nebulae is name-designated heic1118.
10 - NCG 1999 the reflection nebulae in the constillation of Orion and is illuminated by star V380 Orionis.
The nebulae lies 1,500 light-years away.
HST (unknown filter) - NASA

  Originally thought to be next to a dark Bock gobule type cloud, the 3.5 MSol variable V380 Orionis is shown instead to be centrally imbedded in an empty hole. A realisation better fitted to the models for protostellar development.
  Using this different interpretation, the ‘hole’ is more representative as an upper feature, half of an hourglass bi-polar protostar remnant, which V380 now seems to be clearing with its radiations; which would also make V380 responsible for exciting the nebulae into reflection emissions.

10 - RCW 120 Nebulae - (Image inverted in the horrizontal plane)
A gas and dust bubble with a massive protostar or
A Birkeland current cable?

Herschel 3.5 meter Space Telescope (Infra-red) 07 May 2010

  Some differences in interpretation seem to have been stirred by this i-r image of what the Herschel ST science team say is a bubble of gas and dust in the collapsing RCW 120 Nebulae.

  The Herschel team, investigating high mass protostars, propose that a number of stars ≥ 8 MSol are forming in walls of the bubble of the nebulae. They interpret that the radiative outflow of the central star, has created a high pressure bubble around it that is expanding into the walls of the collapsing nebulae, causing density imbalances in the surrounding material. This in turn promotes gravitational attraction of volumes of particle material within the cloud, to cause proto-stellar cells to develop and to form protostars; in accordance with the accepted theory of accretion models.

  A cited comment by Stephen Smith, a plasma physicist, who apparently is replying to the detail of a paper produced by the Herschel team, pursues the debate with the comment that; Astrophysicists continue to puzzle over the fact that some stars accrete more mass during their gestation than is theoretically possible. Since the collapsing cloud of gas and dust that gives birth to stars is supposed to envelop them in a fragile shell, a large formation should generate more radiation as it condenses than its structure can survive. In other words, the shell of gas and dust around those embryonic stars should [be] blow away before that much mass can accumulate.
  Smith then places his argument by saying that the object the Herschel team has discovered, does not obey the tenets of conventional theory because it is not what the astronomers think it is. Smith then explains the image in terms of a plasma phenomenon. Smith segways into a discussion on temperature by stating that the bubble's temperature (infrared emissions) is also open to question; however because we have no data as to what the question is, other than the assumption that the telescopic filters show the heart of the bubble in misty blue, probably tuned for hot hydrogen or helium emissions, we leave this comment alone, only with Smith’s reminder that synchrotron radiation is created by electrons moving in a magnetic field, and is non-thermal.
  Smith argues that the somewhat concentric filaments prompt plasma physicists to conclude that we are not seeing an expanding bubble in RCW 120, but are looking down into a Birkeland current cable; since moving electrons constitute an electric current, and that current travels along a magnetic field, it is a field-aligned current, otherwise known as a Birkeland current. A current pinching itself into an hourglass form that is creating and powering the central star. The instabilities within the nebulae are plasma instabilities that can pull in material and compress it, as well as cause it to spin.
  The toroidal filaments couple to the hourglass-shaped current sheets and are subject to diocotron instabilities: the current flow through the plasma will sometimes form vortices that can evolve into distorted curlicue shapes. This phenomenon has been witnessed in many laboratory experiments, as well as in the polar aurorae.
  Smith concludes that the massive protostars in RCW 120 are most likely massive electric currents flowing through plasma.

  We now interpret Smith to mean that; what we are seeing around the hot blue-giant in RCW 120, are not newly forming protostars, but rather, a stormy curlicue cloud filled with bolts of lightning.
  Well I be dipped in shit! As Larry Niven and Jerry Pournelle have said in Lucifers Hammer; science is better than fiction.
LL Ori young star in the Orion Nebula M42 - HST 2002_hs-2002-05-a-full_990w
10 - LL Ori young star in the Orion Nebulae M42
The young stars outflow of emissions bends in shock to the flow from older stars emerging nearby
HST 2002 - NASA and the Hubble Heritage Team (STScI & AURA), CR O'Dell Rice University

10 - Caption

IC434 - Horsehead Nebula in Orion_red_The big star (white) directly above the 'head' is Alnitka, tha left star of Orions belt_990w
10 - IC 434 - Barnard 33 - The Flame and Horsehead Nebulae in Orion in red
Don J McCrady; Visible spectrum; (Filters unknown at this time)

  The big star (white), directly above the 'Horsehead', is Alnitka; the left star of Orions belt
IC434 - Horsehead Nebula in Orion_real-colour
10 - IC 434 - The Horsehead Nebulae in Orion real-colour
DSS Consortium

  The dark cloud of cold dust and gasses of The Horsehead is fortuitously visible only because it is silhouetted against the bright background of an emission nebulae. The ‘neck’ is about 0.25 pc (0.82 ly) across and the emission nebulae behind at 1,500 pc (4,890 ly) distant.
IC434 - Horsehead Nebula in Orion_real-colour_DSS_02b_990w
10 - IC 434 - The Horsehead Nebulae in Orion - Close up
DSS Consortium

Flame+Horse Head+NGC2023 nebulae in Orion_far Infra-red_5July2012_Wide field Infrared Survey Explorer (WISE)_NASA_JPL_Caltech_990w
10 - IC 434 - Barnard 33 - The Flame, Horsehead and NGC 2023 Nebulae in Orion – Far Infra-red
Wide field Infrared Survey Explorer (WISE)~5th July 2012 - NASA, JPL & Caltech
Wavelength: 3.4 microns = Blue; 4.6 microns = Cyan (blue-green); both representing hot objects like stars.
Wavelength: 12.0 microns = Green; 22.0 microns = Red; represent cooler objects such as the dust of the nebulae.

  Showing a field of view similar to the (red) image above; the colour composite infra-red imagery of WISE conveys a greater depth of view than its optical counterpart, by capturing the more penetrating far infra-red wavelengths. Here there is more contrast shown, by the differences in temperature, to the structure of the molecular and dust clouds of the general nebulae. Many more stars, particularly new young stars incubated within the clouds, are now visible.
  The driving star (NGC 2024) behind the Flame Nebulae is revealed in the large bright patch at the top of the image. Astronomers estimate its mass at some 20 times that of M-Sol, with a luminosity in the visual optical spectrum attenuated, some 4 billion fold, by the dust and gasses of the nebulae.
horse-head_Dust-glows-in-the-far-infra-red_WISE_5July2012_250w  Directly below the Flame, is another bright but smaller patch known as the NGC 2023 nebulae.
  Highly prominent in the visual spectrum, and indeed the left star of Orion’s Belt – Alnitak (Sigma Orionis) – is nearly lost to visibility in the glare of the Flame in this WISE image. Just to the right of the Flame nebulae itself, and slightly outside the pink-glowing area, is an unremarkable, more white than blue, star; a star that is more or less directly aligned above the falling right-edge of the large nebulae cloud; this is Alnitak. Situated some 736 light-years away, this is a multiple blue-giant star system.
Shock-front-in-the-ISM-from-a-fast-moving-star-in-Orion_WISE_5July2012_250w   Coming down the falling right-edge of the large nebulae cloud, below Alnitak, the Horse Head nebulae is nearly lost in transparency; as a second wispy prominence from the cloud-edge, with a whity-blue star now appearing from behind the back of the Head; a star that is just about hidden by the ‘left ear’ of the Horse Head when viewed close-up in the visual spectrum.
  To the far upper-right of the WISE image, is an un-presupposing large blue-white star; this is the middle star of Orion’s belt, Alnilam; not shown in the visual-red image above, but captured within the off-set field of this WISE image. Astronomers note that Alnilam is a variable blue super-giant at 1,980 light-years distant. It has a radius some 24 times R-Sol and a luminosity of some 275,000 L-Sol.
  Quite remarkable in this WISE image, is the white star with the red crescent, a little to the right of, and below, the wispy Horse Head. This we are informed is a multiple star system of blue-dwarfs, at some 1,070 light-years distant. Hurrying through the interstellar medium (ISM) at some 2k4 km/sec (5Meg26 mph), the solar winds and ultra-violet outpourings of the system creates a bow-shock front as it collides with and compresses the ISM into a boundary crescent, that glows in the infra-red with the frictional energy of collision.

Dim-Giant-Star_in_Flame+Horse Head nebulae in Orion_visual-red_Don J McCrady_990w

  Prominent in the infra-red WISE image, is the largest blue-white star (to the right of Alnitak). In the visual spectrum (incert above), this star is an obscure red-star of the field. The star is shown highlighted in a circle, from a slice taken from the visual-red image above. Hidden behind the dust of the nebula, the star is probably a red-giant or red-super-giant, to appear so brightly exposed in the WISE infra-red image.
10 - IC434 - The Horsehead Nebula - Barnard 33 @ 1,500 lt-years distant. Fringe of a molecular cloud and star-nursery in the infra-red.
HST 19th April 2013; WFC3 infra-red. NASA, ESA and STScI

10 - IC 1396 - The Elephant's trunk Nebulae in Cepheus

10 - IC 1396 emission nebulae - The Elephant's trunk Nebulae in Cepheus

(Source Unknown)

nebula_Dark Globule in IC 1369 - Elephant's trunk Nebula_NASA_JPL-Caltech, W. Reach (SSC-Caltech)_02 10 - IC 1396 emission nebulae - The Elephant's trunk Nebulae in Cepheus

Spitzer ST (Infra-red) 19-12-2003 - NASA; JPL-Caltech, W. Reach (SSC Caltech)

  Spitzer exposing the structure of the nebulae. Foreground stars, outside the nebulae, show as pink dots. Young stars, seen sculpting the dust and gasses of the nebulae; and background stars; show through the general dust of the nebulae, as light blue dots.
Serpens_south_infra red Spitzer ST_990w
10 - Serpens South sector
Spitzer ST (Infra-red) 27 October 2006 - NASA; JPL-Caltech; L Allen (Harvard-Smithsonian CfA) & Gould's Belt Legacy Team

  A cluster of stars forming in the Serpens constellation. This cluster, called Serpens South, is a relatively dense group of 50 young stars, 35 of which are protostars just beginning to form. The cluster was observed by a team of scientist led by Dr. Robert Gutermuth, of the Harvard-Smithsonian Center for Astrophysics. The observation was part of a larger project called the Gould's Belt Legacy Survey.
Fomalhaut the star encircled by disc of dusty debris seen for the first time by ir providing insight into planetary evolution - Spitzer (infra-red) ST 19-12-2003_311w-312h 10 - Fomalhaut, a star encircled by disc of dusty debris; is detailed by the infra-red tracing, providing further insight into planetary evolution.

Spitzer ST (Infra-red) 19-12-2003; NASA; JPL-Caltech

Double Helix Nebula @25,000ly mag torsion 1000xT-sol generated by the gas disc orbiting sup-mass Bl-hole at the cent-galaxy @300ly from the nebula_Spitzer ST ir 02-2006_False-Color_990w
10 - The Double Helix Nebulae
Spitzer ST (Infra-red) 15 March 2005 (False-Colour) Multiband Imaging Photometer for Spitzer (MIPS) – NASA; JPL-Caltech; M. Morris (UCLA)

  Looking 25,000 light-years into the dusty heart of the MY Galaxy, Spitzer’s processed infra-red view sees a crowded volume filled with mostly hot red-giants, and red-supergiants; as a murky view of round dots.
  Across the field of view is the intensely hot loop of accelerated material, of ionised gas, spiralling within the twisted fields of torsion created by a magnetic moment estimated to be of 1000 T-Sol; the Double Helix Nebulae.
  Spitzer captured an 80 light-year long section, the Double Helix, of this twisted magnetic tube believed to originate at some 300 light-years away towards the heart of the MW, driven by the suspected super-massive black hole at the centre of the galaxy and supplied by material in-falling from the accretion disk that surrounds it.
A visit to The Great Nebulae in Carinae

10 - The Very Large Telescope (VLT) optical array; 4 x 8.2m mirrors. Paranal Observatory, Atacama-Desert, Chile.
20 December 2010 ESO; José Francisco Salgado
VLT 1 (Antu) 1998; VLT 2 (Kueyen) 1999; VLT 3 (Melipal) 2000; VLT 4 (Yepun) 2001

  Two of four Units making up the Very Large Telescope (VLT) optical array, on a remote mountaintop, 2,600 metres (8,530 ft) above sea level, in the Atacama Desert, Chile. One of the world’s most advanced optical telescopic systems, integrating four adaptive-optic single 8.2-metre (26.9 ft) diameter mirrors into the computer controlled array. The Chilean Paranal Observatory, with the VLT’s operated by the European Southern Observatory (ESO) countries in partnership.
  The Sagittarius-Carinae spiral arm of the Milky Way Galaxy is imaged streaming across the sky.
10 - Looking to the centre of the Milky Way Galaxy down the Sagittarius arm. (Standard orientation - Galectic North = Top)
MPG 2.2 metre telescope (visible), La Silla Observatory, Chile - ESO

10 - The Milky Way Galaxy moving down the Sagittarius arm towards the Carinae sector
MPG 2.2 metre telescope (visible), La Silla Observatory, Chile - ESO

10 - The Milky Way Galaxy. The Sagittarius star cloud (left) and towards the Carinae sector (right)
MPG 2.2 metre telescope (visible), La Silla Observatory, Chile - ESO

10 - The Milky Way Galaxy. Viewable in the Southern hemesphere only; The Crux (The Southern Cross) and the constillation Carinae, above which and just visible as a bright-pink patch (in this image), is the Great Nebulae in Carinae
MPG 2.2 metre telescope (visible), La Silla Observatory, Chile - ESO

10 - The Milky Way Galaxy, East sector. Below the Sagittarian arm of the MW galaxy and below the bright (orange here) glow of the Great Nebulae in Carinae, lie the gravitationally bound companion dwarf galaxies of the MY, named the Large (upper - brownish here) and Small (lower to the left - bluish here) Magellanic Clouds.
DSS Consortium

10 - ALMA millimeter-radio antennae bathed in red light. The Southern Milky Way (left) and the Magellanic Clouds (right)
5th March 2013; ESO, C. Malin

  The Large Magellanic (LMC) and Small Magellanic clouds (SMC) were not named after the famous Portuguese explorer and navigator Ferdinand Magellan until after around 1800, and that only after some reluctance to change.
  Magellan’s famed voyage, the first to circumnavigate the globe between 1519 to 1522 was not actually completed by Magellan, who was killed in a tribal war in the Battle of Mactan in the Philippians by a bamboo spear, and was then hacked to death on the 27th April 1521; nor was his body recovered, being kept as a trophy of war by the tribal victor. A journey started with five ships under Magellan's command – Trinidad, San Antonio, Concepción, Victoria and Santiago – left Seville on 10th August 1519 to find a secure way West, for Spanish ships to navigate to the Spice Islands; but it was captain-master Juan Sebastián Elcano who continued the voyage Westward, in the only ship the Victoria, to complete the circumnavigation of the globe in that direction, an expedition sponsored by Charles V the King of Spain. Only 18 men out of an original expedition of 237, were to return to the home port aboard Victoria on the 6th September 1522.

  The first historic note of the LMC is by the Persian astronomer Al Sufi who in 964, in his Book of Fixed Stars, called it al-Bakr ‘The Sheep of the Southern Arabs’ that could only be seen from the strait of Bab el Mandeb (12°15' N), which is at the southernmost point of Arabia. The pair are later noted to appear in Bayer's Uranometria where they are designated as nubecula major and nubecula minor; and even later in the notes of the French astronomer Nicolas Louis de Lacaille, whom in 1756 designated them as le Grand Nuage, ‘The Large Cloud’ and le Petit Nuage, ‘The Small Cloud’.
10 - The Large Magellanic Cloud (LMC) - A companion dwarf galaxy to the MW. The bright (spot on the left) is the Tarantula Nebulae or 30 Doradus - NGC 2070 (See below).
DSS Consortium

10 - The Small Magellanic Cloud (SMC) - A companion dwarf galaxy to the MW.
DSS Consortium

  The bright patch to the bottom right of the image of the SMC is the large globular cluster 47 Tucanae - 47 Tuc - or NGC 104 (see below) in the constellation Tucana.
10 - The Milky Way Galaxy. The Crux (The Southern Cross), the top of the constillation Carinae and The Great Nebulae in Carinae above it.
MPG 2.2 metre telescope (visible), La Silla Observatory, Chile - ESO

  Below and to the left of Crux, the dark-black patch of cloud gained the name the Coal Sack nebula. In the late 1920’s and through the early 1930’s, the long held idea that interstellar space, or the interstellar medium (ISM), was completely empty or just empty ‘space’ was being challenged. Astronomical observations began to show that ‘space’ was not absolutely devoid of material as had previously been thought; and the Coal Sack nebula became an example of a cloud of cold molecular gas (mostly hydrogen) and dust (conglomerates of fine silicates and water-ices) that blocked and obscured the light from background stars from being observed.
  It was mainly through the observations in the early 1930’s made by the astronomer R.J. Trumpler, at the Lick Observatory, Mt. Hamilton, California in the U.S., that the idea that gas and dust in the ISM was leading to the ‘extinction’ (dimming) of light from the stars and the ‘great nebulae’ (which were later to become ‘galaxies’ because of some of the ramifications that this discovery was to induce), particularly in the plane of the Milky Way (not yet determined as a ‘galaxy’ at that time), which would cause the ‘magnitude’ of light (or electromagnetic radiation) attributed to these objects to be lower than their actual ‘magnitude’, introducing serious errors in the calculations of distances to these objects.
  Ramifications of this discovery would persist for over 70 years as astronomers integrated the parameters of gas and dust ‘extinction’ into their calculations over the entire electromagnetic spectrum from which their data was being obtained. It would induce Edwin Hubble, later in the decade, to redefine the size of the ‘universe’, out of which the term ‘galaxy’ as we understand it today would arise. Because of it, even Hubble’s ‘universe’ would double in size as corrections for ‘extinction’ were recalculated in the 1950’s. Only with the collection of data in the early 1990’s by Hipparcos (High Precision Parallax Collecting Satellite - ESA 1989 to 1993) which normalised for the first time some fundamental ‘standard candle’ distance estimates, did the true size of the ‘universe’ become numerically stable and acceptable to present understanding.
10 - The large star cluster Vikipediya NGC 3523 (left) and The Great Nebulae in Carinae NGC 3372 (right)
MPG 2.2 metre telescope (visible), La Silla Observatory, Chile - ESO

10 - NGC 3372 - The Great Nebulae in Carinae (the Eta Carinae Nebulae) in the Sagittarius–Carinae arm of the MW Galaxy; at a distance of between 6,500 and 10,000 light years from Earth and around 300 lt-yrs in diameter.
La Frontera, Alcohuaz, Chile; Loke-Kun-Tan

  Less well known, due to its location far in the Southern Hemisphere, The Great Nebulae in Carinae is one of the largest diffuse nebulae viewable locally. It is about four times larger and even brighter than the better known Orion Nebulae of the Northern Hemisphere. It was discovered by the French astronomer Nicolas Louis de Lacaille in 1751–52, from the Cape of Good Hope in South Africa.
  The Carinae Nebulae, located North above the constellation of Carinae, contains many multiple young and hot O-type stars. Within it are two of the largest and brightest of the O-type hyper-giants known in the local region; Eta Carinae (in Trumpler 16) and HD 93129A (in Trumpler 14). [HD 93129A originally quoted with a mass of ~120 M-Sol, under closer observation, seems to have been demoted in size because it now appears to be a spectroscopic binary, with individual masses to the order of 60 M-Sol each. A note from the international reference database SIMBAD reads: 2004AJ.128.323N resolved HD 93129A as a double star with a separation of 0.051 ± 0.002 arcsec and a magnitude difference of 0.90 ± 0.05 in the V band. (cited as recently as datad here: C.D.S. - SIMBAD4 rel 1.207 - 2013.05.22CEST00:07:30)]
  The Carinae Nebulae also contains a sub-section called the Key Hole Nebulae (see below).
10 - NGC 3372 - The Great Nebulae in Carinae - Getting closer
La Frontera, Alcohuaz, Chile; Loke-Kun-Tan
Views of the Keyhole Nebula in the Great Nebula in Carinae bkg_set_00_Slot_01
Image Control column + Reset to Base image
[ Move the mouse pointer up & down over Image Select column to change images. ]
10 - The Keyhole Nebulae in NGC 3372, The Great Nebulae in Carinae, at a distance of some 7,500 light-years and about 7 lt-yrs across the ‘hole’.
Base-image: 16" f3.75 Dream Astrograph June 2012, R + HA-O3 (mapped as RGB); Kfir Simon, Namibia

  The Keyhole Nebulae is reported to have been first discovered, detailed and named by Sir John Herschel during his Southern Sky Survey form South Africa, in 1838. Named after its shape, the Keyhole appears as a dark shape highlighted by the bright background of the emission nebulae, The Great Nebulae in Carinae, where it stands out oddly, virtually in the centre. The top, or hole in the key, was reported by Herschel to be brighter than we see today; a cause attributed to the explosion of Eta Carinae in 1843, which clouded the star in such a way that it consequently masked its radiation from exciting the NE side of the nebulae.
  The Keyhole Nebulae is a region of molecular gas and dust in which a young group of mainly O & F-type stars are seen to be dissipating and clearing the remnant materials of accretion, ionized material, in circular rings receding from the stars under the pressure of high energy radiation and pressed by the solar winds of further ionized particles.
  The molecular and dusty materials show as dark regions, and the ionized materials as light regions, in the collected images of the Keyhole Nebulae shown above.
Into the Great Nebula of Carinae (Infra-red) VLT
[ Move the mouse pointer over image to see position of the next image following. ]
10 - Inside NGC 3372 - The Great Nebula in Carinae; general view. The hyper-giant star Eta Carinae shines brightly at bottom left.

The orange tinted Deep Sky Survey (DSS) image, the visible spectrum, captures the young stars of the Trumpler 14 cluster (mid upper), below which (to the left) is the top of the Key Hole, and below it (bottom left) the bright hyper-giant Eta Carinae.
Inset is the HST image (detailed later) of the Key Hole itself, named 'Light and Shadow'.

Underlying the image (mouseover); the power of infra-red viewing is emphasised with the remarkable HAWK-I (Infra-red) camera of the VLA at Paranal, Chili; seeing through the dust of the ISM, the VLT brings out the detail, hidden within the dust, and in particular, also allows a view of some lower temperature and older evolved stars, likely red giants (as orange), not even viewable in the DSS visible spectrum image.

Inside Carinae (visible – orange colour) – DSS
Inset: Light and Shadow in the Carinae nebula - HST; NASA; AURA, STScI.
Sub-image: Very Large Telescope (VLT), HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO

[ Move the mouse pointer over image to see the 5 sub-images (visable & infra-red) inside.]
Into the Great Nebula of Carinae
10 - Inside NGC 3372 - The Great Nebula in Carinae; detailed view. Close views in both the visible and infra-red spectrum.
VISIBLE - MPG 2.2 metre telescope, La Silla Observatory, Chile - ESO
INFRA-RED - Very Large Telescope (VLT), HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO
Into the Great Nebula of Carinae
[ Move the mouse pointer over image for a comparison of the HST image with the VLT infra-red. ]
NGC3372_(inside)-'finger-of-God'-or-'God's-birdie'_HST1999_Keyhole-Nebula_Hubble_1999_01b10 - NGC 3372 (inside) The Keyhole Nebulae. ‘Light and Shadow in the Carinae Nebulae’ & ’the Finger of God' or 'God's birdie'
HST 1999; NASA, Hubble Heritage Team; AURA, STScI
Sub-image: Very Large Telescope (VLT), HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO

  The astronomers dream and the astrophysicist’s nightmare. There is a lot going on in the top of The Key Hole nebulae in Carinae. Hidden in the gas and molecular clouds of the nebulae, young stars, and some quite large ones as well, show circular remnants of photo-dissociated material, under the pressure if ionizing radiation, at all angles, being cleared out by the intense ultra-violet emissions of their new stars.
  Close small clusters of stars clear out bubbles of space within the nebulae material. Bok globules, inside of which new stars have been formed (upper and lower left), suggest them as pink dots in the HST image, but reveal their inner stars to the ir-probings of the VLT.
  'God's birdie' (inset right - as playfully designated by researchers) and the droplets of material below, are possible cocoons for proto-stars, but at this time show no inner stars of any maturity; but glow at their fringes from the radiation of stars in the direction of the 'pointed finger'.
  We are cautioned through these images, that although current astronomical wisdom suggests that globules of molecular material and dust engender proto-stars, not all of them necessarily do so; and some may be destroyed by photo-dissociation and ionization, by nearby stars, before stellar formation may be complete. Explaining it all is a continuing ongoing process for the astronomical community.
10 - Inside NGC 3372 a star cluster irradiates the 'Mystic Mountain' and other molecular clouds in the system.
HST 24 May 2009; NASA, ESA, N. Smith (U. California, Berkeley), The Hubble Heritage Team (STScI/AURA)

  Mystic Mountain (see below) at upper right streaming off ionized material; another threatened molecular cloud at upper centre; the 'Caterpillar' a little to the left of centre, a possible proto-planetary cocoon being eaten away by photo-ionization that glows at its fringes; and the top of the Keyhole Nebulae to the left.
10 - Inside NGC 3372 a star cluster irradiates the molecular cloud material of the sides of the GN in Carinae.
HST 24 May 2009; NASA, ESA, N. Smith (U. California, Berkeley), The Hubble Heritage Team (STScI/AURA)

10 - Inside NGC 3372 the O-type hyper-giant Eta Carinae (see Exploding Stars below) in context with insert (left) for comparison.
HST 24 May 2009; NASA, ESA, N. Smith (U. California, Berkeley), The Hubble Heritage Team (STScI/AURA)

  The extremely hot lobes of bi-polar out-flow from Eta Carinae (just below image centre), believed to have begun at the time the star exploded to be noticed in the sky in 1841; is sometimes mistaken in smaller telescopes to be a double star. As can be seen from these HST images (and any other large optical instruments of today), Eta Carinae appears a single star, but with details somewhat obscured by the dusty bi-polar out-flow (c.f. incert lower left).
  Ionized material is seen to being cleared from the environs of the young bright stars. Possibly Eta Carinae is itself responsible for the cleared hole at the left, entering a volume already cleared by the star inside. Hoops and bands of photo-dissociated material move away under the pressure if ionizing radiation from the group of stars; shaped by radiation and gravity fields.
  At the top centre a cloud glows with dissociated dust at its fringes, being dissipated by the radiation of the bright star below.
NGC3372_04_(inside) Great Nebula in Carina_HST (released on 20th birthday)_PhilcUK-1274438506_990w
10 - NGC 3372 Inside the Great Nebulae in Carinae, an HST image named 'Mystic-mountain'
False colour: Oxygen = blue, Hydrogen and Nitrogen = green, and Sulfur = red
HST February 2010 - WFC3. ESA and STScI (Released on 20th birthday of the launch of the HST)

NGC3372_09_(inside) Great Nebula in Carina_Mystic-mountain_winds-of-radiation_HST_04_990w
10 - NGC 3372 Inside the Great Nebulae in Carinae. The photo-dissociated ionized material streams away from the tip of the 'Mystic-mountain', conditioned by the solar winds of nearby hot young O-type stars.
False colour: Oxygen = blue, Hydrogen and Nitrogen = green, and Sulfur = red
HST February 2010 - WFC3. ESA and STScI

NGC3372_05_(inside) Great Nebula in Carina_Mystic-mountain_winds-of-radiation_HST_02_990w
10 - NGC 3372 Inside the Great Nebulae in Carinae - 'Mystic-mountain' - Winds of radiation
False colour: Oxygen = blue, Hydrogen and Nitrogen = green, and Sulfur = red
HST February 2010 - WFC3. ESA and STScI

NGC3372_07_(inside) Great Nebula in Carina_Mystic-mountain_improbable-reef_HST_02_990w
10 - NGC 3372 Inside the Great Nebulae in Carinae - 'Mystic-mountain' - The improbable reef
False colour: Oxygen = blue, Hydrogen and Nitrogen = green, and Sulfur = red
HST February 2010 - WFC3. ESA and STScI

10 - In the Large Magellanic Cloud (LMC) - The Tarantula Nebulae that holds: 30 Doradus - NGC 2070, alongside Star cluster NGC 2100, NGC 2044, Pit NGC 2081 + NGC 1974, The Ghost Nebulae - NGC 2080 and NGC 2048, among others.
MPIA-ESO (ESO-MPI) 2.2m + Wide Field Imager (WFI), B+V-bands + H-alpha + [OIII] narrow bands; ESO, Cerro La Silla, Chile.
21st December 2006, Mosaic ESO - MVM pipeline by the Advanced Data Products (ADP) group
João Alves (Calar Alto, Spain), Benoit Vandame and Yuri Bialetski (ESO) , Colour composite Bob Fosbury (ST-EcF)

The Eagle Nebulae

A nebulae of considerable beauty, and much favoured by astrophotographers, provides a lead in the science of star formation.

10 - M16 (wide-angle view) - IC 4703 - The Eagle Nebulae (or The Star Queen Nebulae) & Star cluster NGC 6611
In the constellation Serpens Cauda, the Tail of the Serpent
Celestron C10N @ f/4.7 16 July 2010; (RGB), Baader MPCC, QHY8, TS OAG9mm, QHY5 guiding camera
Astrophotography by Matija Pozojevic, Petrova gora, Croatia, Europe

  An emission nebulae of molecular and ionized hydrogen and dust, driven to glowing by the ultra-violet radiation outpouring from a group of young 5 million year old stars, that was first discovered by the Swiss astronomer Jean-Philippe de Cheseaux in around 1745-46 on account of the bright open star cluster that attracted his attention; now designated NGC 6611. The faintly glowing oval nebulae of hydrogen gas and dust from which they were formed, extending across some 20 light-years and at some 6,500 light-years distant, a little more difficult to perceive, was to be later noted in June 1764 by the French astronomer, Charles Messier, who gave it the designation M16; now also designated IC 4703.
  The name Eagle, is derived from the shape of the outstanding silhouette of the dark central molecular cloud region, which at the resolution of small-aperture telescopes, resembles a large bird in flight. The Star Queen designation introduced by Robert Burnham Junior, is most likely derived from a combination of ideas that include; the prominence of the open cluster (Star); and the shape of the outlying nebulosity itself, which resembles a fabulously luxuriant thin-waisted ladies (Queens no less) dress.
10 - M16 - IC 4703 - The Eagle Nebulae (or The Star Queen Nebulae) & Star cluster NGC 6611
In the constellation Serpens Cauda, the Tail of the Serpent
NOAO 0.9m (35.4 in) telescope Kitt Peak ~26 February 2006 , Arizona, USA; NOAO, AURA; TA Rector & BA Wolpa

  NGC 6611, the star cluster in the Eagle Nebulae, is estimated to contain around 460 stars. Its brightest star, HD 168076 of type-O, has been discovered to be a binary; comprising an O3.5V + an O7.5V companion. The large star estimated to mass ~80 M-Sol, with a luminosity of ~1 Meg L-Sol, and of age 1-2 Meg years; a recent member to the cluster estimated to have begun forming for around 5 Meg years.

  An astonishingly evocative image of an alien aquatic landscape bubbling in a fish-bowl. A lovely example of science melding with art. The science is serious, and the arty fish-bowl landscape effect is however real in somewhat astonishing dimensions.
  One is indeed serendipitously viewing into a ‘bowl’; the inside of a cold molecular cloud of mainly hydrogen and accumulated dusty particles of matter, the centre of which is now being sculpted by a young cluster of energetic O-type stars, which were themselves formed earlier from the material of the cloud, but the dimensions of this cavern are awesome. Just under some 20 light-years across and about 15 light years from top to bottom in this view, one looks into a glowing cavern to an order of another 15 light-years in depth. There is no real ‘back’ of the cavern that one can discern, rather it is the re-radiated emanations of very tenuous quantities of ionised hydrogen that provides the glowing back-drop to silhouette the ‘pillars’ of denser gas and dust that now appear to lie in the foreground. The high ultra-violet radiation of the star cluster NGC 6611 provides the driving radiation that makes the internal cloud glow; and their outpourings are eating away at the ‘pillars’, braking down the molecular material into charged ionised particles which are being driven outward and away by the radiation and the stream of solar wind-particles emanating from the stars. These radiations are now so powerful that the outer cloud material itself is being dispersed outwards, thus forming a cavern. Serendipitously the side of the cloud through which one views this vast panorama is now so tenuous and dispersed that one can look inside with the visual spectrum.
  The bubbly effect being provided mostly by foreground polluting stars, however the star cluster NGC 6611 is embedded in the cloud together with a lesser number of stars; all of which are acting to eventually disperse the cloud.
10 - The Pillars of Creation in/and The Eagle Nebulae - M16 - IC 4703

The Pillars of Creation in The Eagle Nebulae
0.8-meter (31.5 in) telescope in the Canary Islands, ~ 27 February 2008; filters Hydrogen, Oxygen, and Sulfur; IAC, Daniel Lopez

The Eagle Nebulae - Mapped Color
16 inch RCOS, 18 March 2011, Camera U16, 5 hrs each filter in 20 min subs; Red =Sii, Green = H-alpha, Blue = Oiii; Coral Towers Observatory; Joseph Brimacombe

10 - M16 - IC 4703 - The Eagle Nebulae (or The Star Queen Nebulae)
& Star cluster NGC 6611 In the constellation Serpens Cauda the Tail of the Serpent
The Eagle Nebulae Astrophotography by Keith B. Quattrocchi; Pillars of Creation and NGC 6611 open cluster, HST; The Eagle Nebulae in R-RGB colour by Philip Perkins

  In 1995, the HST probed the Eagle capturing an hall-mark image that NASA-ESA astronomers, at Arizona State University, named the ‘Pillars of Creation’; of which a later enhanced copy is shown (above). Astronomers now commonly refer to the central gas-cloud region of the Eagle by this name, and also have come to use the term ‘pillars’ to describe these clouds; but in all cases the name the ‘Pillars of Creation’ is respectfully attributed to this 1995 HST image, the HST and her science team.
  A surviving fragment of the same kind of material that comprises the whole cloud that is the Eagle nebula; the pillars are of cold dust and molecular gas, mostly hydrogen, that have survived the onslaught of radiation from the star cluster NGC 6611 that is above them. It has been found that they have survived better than the surrounding material, which has now been irradiated away, because they contain a cap of particularly dense molecular hydrogen that has slowed the process of dispersion.
  The HST image helped to substantiate part of a theory of proto-stellar formation, that had been advanced previously, but was still a little woolly in some of its detail. The successful part was the discovery in the detail that only the acuity of the HST could provide, not at the time clear from ground based observations, that the cloud contained nodules of concentrated material in which it was supposed new stars were forming. Over 70 nodules were identified in the HST image, mostly at the edges around the cloud pillars, and some separated entirely from the cloud. Some of the nodules, but not all, showed tinges of red in their centres, indicating the presence of newly forming stars. These nodules engendered the phrase ‘evaporating gaseous globules’, which conveniently shortens to the acronym ‘egg’s’. It is the formation of the egg’s that is the woolly part of the theory in that one interpretation has that the egg’s are stimulated to form by the disturbing irradiation from the newly formed star-cluster, precipitating a cascading sequence that will eventually consume the cloud, but to leave a string of new stars in the process. In parallel with this idea is that gravitational perturbations within the cloud has already engendered proto-stellar egg’s. It is the stimulation-by-radiation idea that is proving a little difficult to pin down, however both ideas seem to hold; but what is also clear from the HST image, and from other sources, is that the radiation of the star-cluster is eating away all around the cloud, and evaporating the egg’s as well. So any newly formed stars to follow may be stunted in size as some of their available accreting material would have been blown away.
  To see the newly forming stars in the pillars egg’s, provided in the first place that the ‘yoke’ of the egg’s has been gravitationally compressed sufficiently to ignite a proto-star, requires the use of telescopes seeing in lower infra-red or radio parts of the spectrum; or if they are of large mass and very energetic, wavelengths of high ultra violet or even x-rays need investigating. Such probings have been done; with the result that a few eggs show proto-stars, but not all; and that generally they are of low mass; and it is thus supposed that many are as yet too young to have formed proto-stars, a process that post-egg-formation, after all, takes about a further 100,000 years.
10 - Stella spire or Fairy in/and The Eagle Nebulae - M16 - IC 4703

Stella spire Sh2-49, RCW 165, Gum 83; HST - ACS, WFC2, 2004; posted 7 July 2006
The Eagle Nebulae in Mapped Color, H-alpha; Astrophotography by Russell Croman;

10 - Caption

Death of Stars - Planetary Nebulae + Exploding Stars

Planetary Nebulae

Boomerang (planetary) Nebula in Centaurus @5,000ly - fierce 500,000 kph wind blowing ultracold gas away from central star_HST WFPC2 1998_hs-2005-25-b-full_tif_990w
10 - Boomerang (planetary) Nebulae in Centaurus @5,000ly distant. A fierce 500,000 kph wind blowing ultracold gas away from a central star
HST WFPC2 1998; NASA, ESA, R Sahai and J Trauger (Jet Propulsion Laboratory) and the WFPC2 Science Team

Boomerang (planetary) Nebula in Centaurus @5,000ly reflecting dust & gas - HST - bipolar outflow - 2 lobes (1 ly each) of matter being ejected from an old red giant_hs-2005-25_990w
10 - Boomerang (planetary) Nebulae in Centaurus @5,000ly reflecting dust & gas; Bipolar outflow in 2 lobes (1 ly each) of matter being ejected from an old red giant
HST Advanced Camera for Surveys (ACS), visable light and polerisation filters; NASA, ESA and The Hubble Heritage Team (STScI; AURA); J Biretta (STScI)

Egg (planetary) Nebula dust layers extending over one-tenth ly in an onionskin structure around star_HST in polerised light 03-04-2003_Rainbow image of Egg Nebula
10 - Egg (planetary [Check this]) Nebulae in Cygnus as a rainbow image. Dust layers extending over one-tenth light-year in an onion-skin structure around star.
HST (In polerised light to create a rainbow image) 03-04-2003 - NASA STScI + AURA; Team led by W Sparks

Un-named (planetary) Nebula_HST 1999_hs-1999-35-d-full_tif
10 - NGC 2346 planetary and emission nebulae is a glowing patch of gas about 0.2 pc (0.65 ly) across and lying some 700 pc (2,282 ly) away
HST 1999

NGC3132 planetary nebula @2,000ly dia ~ ½ly Ring material (blu=hottest,red=coolest) recedes from tiny old (white-hot) carbon-rich star (left of unrelated bright star at centre)_STScl_AACHDCU0
10 - NGC 3132 - Eight-Burst (Planetary) Nebulae, Southern Ring Nebulae, Caldwell 74, Bennett 43
HST 1998-39 STScl - (Filter: blue=hottest, red=coolest)

  NGC 3132 is a Planetary nebulae @ 2,000 ly distant with a ring dia ~ ½ light-year. The ring of gases is moving away from its central carbon-rich white dwarf at a speed of 14.4 km/s (9 mi/s).
  The white dwarf (16th magnitude) is the star on the left of an unrelated bright star (10th magnitude) near the centre of the nebulae.
  The name Eight-Burst applies because of its figure-of-8 appearance through small (amature) telescopes (right).

NGC 3132 - Bennett 43 - Eight-Burst (Planetary) Nebulae - San Esteban (Chile) - 13Mar2004

Note: The above is a good example of limitations faced by astronomers; when the aperture of a small sized telescope causes the true case to be hidden. In the small aperture instrument, the polluting star appears the centre of the Eight-Burst Nebulae; where the correct white dwarf only becomes apparent with the resolving power of the larger instrument.
NGC3132 - Bennett 43 - (Planetary) Eight-Burst Nebula - San Esteban (Chile) - 13Mar2004
NGC7293 - Helix Planetary Nebula in Aquarious with white dwarf @700ly (unknown filter)_990w
10 - NGC 7293 - Helix (Planetary) Nebulae in Aquarious with white dwarf @700ly (215 pc) (unknown filter)
HST DSS Consortium

NGC7293 - Helix Planetary Nebula in Aquarious with white dwarf @700ly (unknown filter 2)
10 - NGC 7293 - Helix (Planetary) Nebulae in Aquarious with white dwarf @700ly (215 pc) (unknown filter 2)
HST Jack Newton

NGC7293 - Helix Planetary Nebula in Aquarious with white dwarf @700ly in infra-red_990w
10 - NGC 7293 - Helix (Planetary) Nebulae in Aquarious with white dwarf @700ly (215 pc) in infra-red
Spitzer ST - NASA JPL-Caltech + K Su University of Arizona

NGC7293 - Helix Planetary Nebula in Aquarious with white dwarf @700ly (multiple filter)_990w
10 - NGC 7293 - Helix (Planetary) Nebulae in Aquarious with white dwarf @700ly (215 pc) (multiple filter)
(composit) HST + Cerro Tololo I - NASA ESA NOAO; C R O'Dell (Vanderbelt) & M Meixner (STScl) + P McCullough

NGC7293 - Detail Helix Planetary Nebula in Aquarious with white dwarf @700ly by Hubble and the Cerro Tololo I
10 - NGC 7293 - Detail Helix Planetary Nebulae in Aquarious with white dwarf @700ly (215 pc) (multiple filter)
(composit) HST + Cerro Tololo I - NASA ESA NOAO; C R O'Dell (Vanderbelt) & M Meixner (STScl) + P McCullough

NGC2392 Eskimo (Planetary) Nebula in Gemini @ 5,000 ly N-red H-green O-blue He-violet_HST WFPC2 10&11-01-2000_hs-2000-07-a-full_990w
10 - NGC 2392 Eskimo (Planetary) Nebulae in Gemini @ 5,000 ly
Nitrogen-red, Hydrogen-green, Oxygen-blue & Helium-violet
HST WFPC2 10&11-01-2000

10 - M57 - NGC 6720 The Ring (planetary) Nebulae in the constellation of Lyra
Spitzer ST in infra-red; NASA + JPL; Caltech; J. Hora (Harvard-Smithsonian CfA); 20th April 2004

  A slightly unfocussed Spitzer ST wide field view image of the Ring Nebulae, with poor resolution of the central dying star (see later images below).
  More of the outer regions of gas and dust of the Ring Nebulae are made detectable in the infra-red, than is normally seen in visible light (see HST colour image below). This is because the outer regions of dust and hydrogen molecules in particular, excited by the ultra-violet from the central star , or the planetary nebulae nucleus (PNN) as it is termed, then re-emit in the infra-red.
  Also caught in this image, at the upper right, is the type SBbc barred spiral galaxy IC 1296 which is normally described as being of low surface brightness and very faint. In visible light, with an Apparent magnitude of 14.8 (V); 15.5 (IVM); details of its structure require modestly large (12"+; 30cm+) instruments to properly discern. Here, the Spitzer ST specialty of infra-red fortuitously comes into play to bring out otherwise unseen detail where; the glowing regions of dust and hydrogen molecular clouds within the arms and disk of the galaxy are now readily apparent. IC 1296 lies in the far distance @ 221.14 Meg light-years (67.8 Meg pc).
10 - M57 - NGC 6720 The Ring (Planetary) Nebulae in the constellation of Lyra
(composit) HST Hubble Legacy Archive + Subaru (NAOJ); Robert Gendler

  The Ring Nebulae is classified as a planetary nebulae of bi-polar type.
  The Ring Nebulae is most likely an hour-glass structure, like the TMyCn18 Hourglass and the NGC2346 nebulae, viewed nearly directly down its axis; some cite that the view is angled at a tilt of some 30 degrees. The filigree of the rose shaped structures would then be artefacts of the lips of the hour-glass, with a little confusion in discriminating the forward (that which is towards us) and the rear portions of the lips. The central throat of the hour-glass being formed by the region around the tiny central PNN which outpours energy in the ultra-violet part of the spectrum, to excite the surrounding material.
  An alternative interpretation is that the Ring Nebulae is similar to the V838 Mon artefact; citing it as an ovoid structure. The filigree of the rose shaped structures would then be polar artefacts of an open globe, with the more symmetric circular features cited as more strongly concentrated in the equatorial regions of the sphere.
  The actual PNN is now resolved as the small central-most star; where the star angled a little to the upper right, is a polluting star nearer to the observer.
  The outer material is estimated to be expanding at a rate of 20–30 km/s allowing an age for the system to be estimated at approximately 1,610±240 years.
  The PNN, formally a red-giant that ran out of helium in its core, is estimated to have had a starting mass of approximately 1.2 MSol. The resultant emerging white dwarf is estimated to have a mass of about 0.61–0.62 MSol, with a surface temperature of 125,000±5,000 K.
10 - M57 - NGC 6720 The Ring (planetary) Nebulae in the constellation of Lyra. A closer view down the throat.
(composit) HST Hubble Legacy Archive + Subaru (NAOJ); Robert Gendler

  This central portion of the composite HST visual colour image (see below) combined with the Subaru narrowband image data in the infra-red region, allows the general overall structures of the Ring Nebulae to become accessible; particularly the lower temperature dust and gas artefacts that comprise the extended outer structures.
  The central ring region, estimated to be about 1 light-year (0.705 pc) across, indicates detail of dust and lower temperature gasses not accounted in the HST visual image alone. Here, the dust and gasses reveal themselves in the red hydrogen-alpha emission at 656.3 nm, forming part of the Balmer series of lines. They are similar to general emissions nebulae spectra, caused by the re-emission at lower frequencies of incident ultra-violet; in this case streaming from the central PNN. The image gives a sense of the 3-dimensional nature of the nebulae; when it is noted that the light ‘comma’ shaped spiral feature, close to the PNN is in the foreground, and a similar sized and shaped feature, now darker, lies slightly askew, under it. If the overall shape of the nebulae is global; then the lower, darker, feature may lie some 1 light-year deeper into the nebulae, than its lighter upper analogue. The slightly spiral nature of some of these features, should remind us that one is viewing artefacts created from a rotating system. Cited is that some of the red tints originate from doubly ionized nitrogen, or [N II], at 654.8 and 658.3 nm; which are forbidden lines, so called because they are not easily accessible to laboratory spectra, on account of the ultra-low density of matter, in the order of a few atoms per sqcm, that is necessary for their existence. These forbidden lines remind us that the material of the star out-gassed to ½ a light-year, is very tenuous indeed. We are reminded that the nitrogen comes from an imperfect and leaky fusion CNO cycle process that fuses hydrogen into helium, which had been ongoing in the outer shell of the core of the red-giant; while the core itself was fusing helium into carbon. It was this dirty hydrogen shell that was out-gassed first; when the core began to run out of helium.
  Another set of forbidden lines is present, this time in the beauty of the central region of the nebulae, and again for the same reason of low density; the blue-green tinge that is caused by doubly ionized oxygen at 495.7 and 500.7 nm. This indicates that the progenitor star was heavy, or massive enough, to run the high temperature thermonuclear process of fusing carbon-12 with helium-4 to form oxygen-16. So from this we may infer that the progenitor star was ≥ 1.2 MSol; and that the remnant white dwarf is a cooling carbon and oxygen cinder.
10 - M57 - NGC 6720 The Ring (Planetary) Nebulae in the constellation of Lyra
HST - Visible True Colour - The Hubble Heritage Team (AURA; STScI; NASA) October 1998

  HST image rotated to match orientation of HST + Subaru composite (above) and thus truncating out some of the outer stars (i.e. they are absent from the image).
  This final 1998 HST image of the Ring Nebulae @ 2,300 light-years (705 pc) distant, the first of such colour and resolution to be generally available, has prompted many astronomers, all science aside, to comment generally at the time; that the Ring Nebulae is one of the most beautiful structures on view; with which Things in the Sky would agree.
  Taken with the ESA’s Wide Field Planetary Camera 2 aboard the HST, the image is filtered in the visual spectrum and thus does not highlight the outer structures that radiate mostly in the infra-red.
  As noted earlier, the aged red-giant started its out gassing some 1,600 years ago, shedding at the time mostly hydrogen to begin, then dredged up helium that it was burning in its core; and if heavy enough at the start, other elements that it was able to synthesize. Blue represents hot ionised helium, which appears present around the PNN. Green represents ionised oxygen, again dredged up during its pulsing phase and red ionised nitrogen, and the radiation of somewhat cooler gasses and dust. The PNN is cited to now consists primarily of a cooling carbon and oxygen remnant, with a thin outer envelope composed of lighter elements.
  The processes of forming a Planetary Nebulae are still not fully understood or modelled, and the study of these systems remains of high interest to astro-physicists. The presence of dark streaks of material in the outer regions of the nebulae raise the question of whether they originated from the ejected material of the star, or are debris of Oort, or less likely Kuiper, objects that existed around the original star system.
10 - IC 418 - The Spirograph (planetary) Nebula, The Red Planetary
PN G215.2-24.2, PK 215-24.1, ARO 3, IRAS 05251-1244 (infra-red)
with HD 35914, as the central (variable) star, herein called the PNN; in the constellation Lepus.

HST Wide Field Planetary Camera 2 (WFPC2); Data taken February & September 1999; Released 7th September 2000
Optical: Deep-Red = 658nm - Nii, Red (near orange) = 656nm - H-alpha and Green = 502nm - Oiii
NASA and The Hubble Heritage Team (STScI/AURA)

  Called The Spirograph nebula in similarity to the mathematical figures produced by a toy that traces geometric (hypotrochoids and epitrochoids) shapes when drawn on paper; the plan-view image of the overlapping pressure-density waves in the out-flowing gasses of the nebula produce this impression.
  The Spirograph is estimated to be 3,6000 ± 1,000 lt-yrs (1,100 ± 300 pc) (error ± 27%) distant; and spans ~0.3 light-years across.

  HD 35914, the central star or PNN of the nebula, has been measured to have a relatively low effective temperature, in the range between 27,000 and 50,000 K; of spectral type mostly between O4f and O7f, in some cases towards Of-WR or even WC; and is a short-period variable.
IC418_The-spirograph-nebula_hs-2000-28-a-full_tif_388w-454h  This (comparatively as will be shown) low temperature helps to imply that the star is a post-Asymptotic Giant Branch (post-AGB) star, or a fading red-giant, which is shedding its outer shell of material, having now run out of nuclear fuel that its mass can gravitationally compress into fusion. It also implies that it is a relatively young planetary nebula, as it has not as yet shed all its outer shell of gasses to expose its core, which when exposed as a white-dwarf, would otherwise exhibit a temperature to the order of ~100,000 K or greater. All this means is that, in the normal evolution of a planetary nebula, the spectra of the PNN will move from the right to left (red to blue) on the HR diagram, as more of the hot core is exposed, due to outer-shell mass loss.
  A further indicator to its youth is the size of the nebula itself, which has been measured to be around 0.3 lt-yr in diameter; or about 38% of the distance to the inner region of the Oort cloud (~50,000 AU), in comparison to our own solar system; being at ~18,750 AU. A more mature planetary nebula would be of the order of at least 0.8 lt-yrs (~50,000 AU) in diameter, or greater.
  The Spirograph is deemed a prototype of its class; as this type and age of object, is not commonly in view.

  In an IC 418 paper on photometric observations published by E. Kuczawska, K. Wlodarczyk, + S. Zola (KWZ); 15th October 1994, from (Krakow Pedagogical + Jagiellonian Universities) Krakow, Poland, before the availability of the 1999 HST image (above), and citing researchers from as far back as the 1960’s; KWZ report that the PNN is a (somewhat irregular) or short-period variable with a quazi-periodicity that lies between 0.d15 and 0.d32, or a period of ~1/4 day (~6.5h) during the time of their observations. They further report that the terminal velocity of outflow to be equal to 940 kms−1 and the turbulent velocity to be roughly equal to 50 kms−1 (sufficient to cause shock fronts); and that the suspected mechanism of wind flow is driven by radiative emissions.
  Our understanding of planetary nebulae behaviour is still incomplete and The Spirograph remains under study to aid this understanding. What can be implied from our current models of star behaviour as applied to The Spirograph is that as a planetary, the original mass of the star would lie somewhere between just less than 1M-Sol, to just around 8 M-Sol. Only stars within this mass range become planetaries. We also know that it is a post helium-flash star, and that it was converting, in the main, helium into carbon before the helium fuel ran out; but still had a shell of hydrogen fusing helium around it. Further, that in its current state, it has now ejected its outer hydrogen to helium burning shell, and is in the process of ejecting its inner helium shell.

  The HST image implies the extent to which the hot outer hydrogen shell has been expelled, to the outer brown-orange regions of the nebula; although an infra-red image would show a nebulosity of cooler hydrogen to possibly twice the extent of this visual image. Low density ionised hydrogen will occupy the volume in towards the secondary smaller blue shell that surrounds the PNN. The blue shell now being the region of ejecta of mainly helium that is expanding away from the PNN.
  Why the PNN ejects its shells in this manor, is one of the processes that is under continuous investigation. The spirographic features seen in the image of the nebula represent high density wave-fronts of slightly asymmetric shells of gas ejected by the PNN. At the distance viewed these features, which are in fact immense in dimensions to the order 10’s of millions of miles, are optical artefacts conveying differences in gas density; in a perspective view, much like ripples on a pond. Although these are interference wave features, they represent only some very low frequency harmonics of wave-fronts of ejected shells, and are thus only remotely related to the actual frequency of shell ejection. A similar analogy applies to a view of the sea from a high altitude; a closer view reveals smaller waves; and so a closer approach to the nebula would yield more detailed high frequency components of density fluctuations.
Exploding Stars

NGC6751 - The Glowing Eye Planetary Nebula in Aquila_HST NASA The Hubble Heritage Team AURA_Filter for ionized-Oxygen(++)=blue; Hydrogen(+)=green; Nitrogen(+)=red
10 - NGC 6751 - The Glowing Eye (Planetary) Nebulae in the constellation Aquila
HST WFPC2 1998 NASA - Arsen Hajian of the U.S. Naval Observatory in Washington, DC. & The Hubble Heritage team, working at the Space Telescope Science Institute in Baltimore - AURA
Filter for ionized: Oxygen(++)=blue; Hydrogen(+)=green; Nitrogen(+)=red

  Roughly estimated to be at a distance of some 6,500 light-years, with an estimated diameter of 0.8 light-years, the nebulae would be some 600 times the diameter of our own inner solar system at the moment the image was captured.
   The carbon white-dwarf at the centre is estimated to have a surface temperature of approximately 140,000 K.
   Blue regions mark the hottest glowing gas, with orange and red showing the locations of cooler gas.
   The presence of a high percentage of oxygen in the efflux at the centre of the nebulae, marks the progenitor star as of large starting mass in the region of 3 to 8 M-Sol.
   Planetary nebulae, although being a feature of the end of a stars life, are useful for the study of the development of planetary systems as a whole. This may seem a bit odd, but when it is considered that, to the observer, it appears that an intense flashlight has gone off in the middle of a distant solar system, lends credence to the argument. This allows the observer to see features of the system that would not otherwise be apparent at the distances involved.
   Some care is needed in interpretation, as this is a 3-dimensional object seen in 2-D. One is viewing through a ball of thin glowing gas and a global spray of debris. The apparent ‘ring’ (or ‘rings’) being a view through a longer depth of material at the outer edges of a ball.
   The Glowing Eye nebulae shows some very interesting features. The blue circle, which does not quite reach the brown debris of the outer system, is glowing ejected outer shell material of the star. The high oxygen content suggests that the star has already lost its outer shell of fusing hydrogen, and now remains with a naked helium shell that is not only fusing to carbon, but is also fusing to oxygen. It is the helium shell that is now being dissipated as solar winds around the star. The presence of oxygen suggests a large mass star.
   This glowing shell is the proverbial flashlight. Many other features are reflected from this light. Recall that although the shell of gas may be moving, its light moves faster and ahead of it, illuminating features far and outside its ring.
   Throughout the nebulae can be seen, both inside and out, matter being stripped outwards, from fixed points to trails of material cast by previous and present outflows of the solar wind. The turbulent flow suggests, as expected, the passage of slightly asymmetric shells of ejected material from the star; a feature of many planetary nebulae.
   The 3-D view somewhat clouds the next interpretation. There appears to be two or three rings of material being stripped by the solar wind. The inner brown regions, the outer reddish regions, and the obvious outer light brown regions. The numbers not being that significant at this point, but the overall picture being that planetesimals, or groups of planetesimals, are being destroyed by the heat of the passage of the solar winds. For the outer regions this is not surprising, as these objects lie on a circle of 0.8 lt-yrs in diameter; similar to the position of the Oort cloud in our own solar system which inhabits a region of 0.79 to 1.58 lt-yrs in diameter.
   The inner planetesimals are more problematic to explain, other than a 3-D effect, as there is no analogue to them in our own solar system. One needs to recall two things here to clear this point. The first is that the inner solar system of Sol, at Neptune’s orbit, is only some 9 light-hours across; a distance minute to the scale of this image, a dot obscured behind the brightness of the Glowing Eye’s white dwarf itself. The second is that the Glowing Eye star was previously a red-giant and would have long past destroyed any planetary objects around it; we see the Glowing Eye now, 10’s of millions of years after the fact.
   There are other possibilities, but their merits are marginal. One is that; could a planetary object of the inner system, provided it was large enough, survive the onslaught of a solar wind for 10’s of millions of years, and be moved out of its orbit, to the extent of ~0.2 of a light-year? Or could its detritus alone, survive to show a streak? Another is that; one is viewing a completely different solar system of completely different (and unknown) structure. Could resonances of its orbiting components throw out two or three Oort clouds? Or could there be a far flung Kuiper belt? The future will tell.
   The other interesting feature of the Glowing Eye system, similar to that of NGC 6543 the Cat's Eye nebulae in Draco, is the brown ‘lace’ at the bottom of the image; an obvious component of the system, but outside the ring. An artefact of bi-polar outflow? When? The present system does not indicate strongly any tractable features that suggest bi-polar out-flow for this system; or not at this present time anyway. Yes for NGC 6543; but not for this system. But there is little note elsewhere of another possibility, one that may have been overlooked. We only see this artefact in the light of the nebulae. If the star had not out-gassed, we would not know it was there. Is it a left over artefact of bi-polar outflow from the systems formation some billions of years ago?
10 - NGC 6826 - Eye-Shaped (Planetary) Nebulae in Cygnus
DSS Consortium

NGC6826 - Eye-Shaped Planetary Nebula in Cygnus (uninhanced)_DSS -consortium_450w
NGC6826 - Eye-Shaped Planetary Nebula in Cygnus (uninhanced)_2b_layered_2_450w 10 - NGC 6826 - Eye-Shaped (Planetary) Nebulae in Cygnus (uninhanced)
DSS Consortium

A composite image; the star field of the planetary nebulae with an enhanced image set to scale in the apparent star, to illustrate the size of the detail.

10 - NGC 6826 - Eye-Shaped (Planetary) Nebulae in Cygnus
HST - Bruce Balick + Jason Alexander University of Washington

An enhanced view of the Eye-Shaped planetary nebulae, in false colour, to emphasise different features of the star.

NGC6826 - Eye-Shaped Planetary Nebula in Cygnus_3_r+30.26+m0.65_450w_black
NGC6543 Cat's Eye (planertry) Nebula in Draco_00a_450 NGC6543 Cat's Eye (planertry) Nebula in Draco_00a_comp_450w
10 - NGC 6543 Cat's Eye (Planetary) Nebulae in Draco
DSS Consortium
The scale of detail within the 'Eye' of the nebulae

NGC6543 Cat's Eye (planertry) Nebula in Draco_05_suggests near end double-star HST WFPC2 3,000 ly_hs-1995-01-a-full
10 - NGC 6543 Cat's Eye (Planetary) Nebulae in Draco @ 3,000 ly
Suggests near end double-star system

NGC6543 Cat's Eye (planertry) Nebula in Draco_08_a_Chandra ACIS X-ray 10&11-05-1999 central star & cloud of multimillion-degree gas_chandra_xray&optical_990w
10 - NGC 6543 Cat's Eye (Planetary) Nebulae in Draco @ 3,000 ly
Chandra ACIS X-ray 10&11-05-1999 central star & cloud of multimillion-degree K gas

NGC6543 Cat's Eye (planertry) Nebula in Draco_10_b_chandra_xray&optical_990w
10 - NGC 6543 Cat's Eye (Planetary) Nebulae in Draco @ 3,000 ly
NGC6543 Cat's Eye (planertry) Nebula in Draco_11_composite of Chandra X-ray (blu) and HST (red & pur) NGC 6543 end Sol sized star - Cat's Eye Nebula_990w
10 - NGC 6543 Cat's Eye (Planetary) Nebulae in Draco @ 3,000 ly
Composite of Chandra X-ray (blu) and HST (red & pur) - end Sol sized star

NGC6543 Cat's Eye (planertry) Nebula in Draco_12_suggests near end double-star HST WFPC2 18-09-1994 3,000 ly_hs-1995-01-b-full_2_r+180-40_A_990w
10 - NGC 6543 Cat's Eye (Planetary) Nebulae in Draco @ 3,000 ly
Colour reduced for better contrast (rotated to match image above); Some astronomers suggest that this image may indicate a close binary, or double-star system, entering old age
HST WFPC2 18-09-1994

MyCn18 Hourglass (planetary) Nebula_HST 16-01-1996_hs-1996-07-b-xlarge_web_990w
10 - MyCn18 Hourglass (Planetary) Nebulae
HST 16-01-1996

10 - Caption

Remnants and Super Nova

Supernova 1987A_HST WFPC2_b_hs-1995-49-a-web_print_c990w
10 - Supernova SN 1987A
HST WFPC2 1995; C. Burrows (ESA/ STScI), HST, NASA

Kamiokande under Mt Ikeno

Kamiokande (1986) - The original neutrino detector that observed 11 neutrinos from SN1987A.
Kamiokande under Mount Ikeno, Kamioka Observatory, Kamioka mine, Kamioka cho, Yoshiki gun (now Hida city), Gifu prefecture, Japan.
Kamioka Observatory, Institute for Cosmic Ray Research (ICRR), University of Tokyo

  Kamiokande was originally designed as a proton decay detector when it started operation in 1983. It was later modified for solar neutrino detection.
  Housed in a 16m high by 16m diameter tank with 1,000 novel photomultiplier units, the upgraded detector system saw first light at the end of 1986.
  The detection of neutrinos from SN1987A stimulated the need for advanced neutrino detection systems; which resulted in the planning for a Super-Kamiokande detector in the early 1990's.
  The detection of neutrinos from SN1987A also brought further prestige to the University of Tokyo and the Kamiokande facility when its project director, Dr. Masatoshi Koshiba, was awarded a Nobel Prize in Physics in 2002 for the facilities pioneering efforts in the field of neutrino astronomy.

  Note, the two white objects are stars polluting the field of view.
  Provoking much astrophysical speculation at the time this image was taken by the HST in 1995, the triple ring arrangement around the remnant of supernova 1987A, a supernova discovered near the Tarantula Nebula in an outer spiral arm of the Large Magellanic Cloud, in the constellation Dorado, was a bit of a mystery. Its dimensions were much too large to be the immediate left-over remnants of the supernovae itself; which is just the bright spot within the small bright ring.
  It has taken a bit of time, and repeated observations of the object, to unravel the components of the image, but it goes something like this.
  Supernova 1987A was previously a blue supergiant star, consequently identified as Sanduleak -69° 202, but by the theories of that era, was not expected to go nova. An idea that was clouded by the rarity of observable supernovae events, but that has now been updated to one of expectancy, by our understanding from better modelling of these high mass stellar evolutionary phenomenon.
  By observation of the behaviour of the light reflected off the three rings of material around SN 1987A, the dimensions of the rings, and by consequence the distance to the object, have been estimated. The bright inner ring being some 0.808 arcseconds (0.66 light years) in radius, that helped the computation of the distance to the supernova, being at around 51.4 kiloparsecs (168,000 ly).
  Considered a type II or core collapse supernova, SN 1987A was a bit odd being about as one-tenth as luminous as that expected for its type. But its type was generally classified from red supergiants, so here now was an example from the blue supergiant family, somewhat younger stars. It turns out that some 20,000 years before the progenitor star Sanduleak -69° 202 went supernova, it puffed in the traditional bi-polar way, leaving material in a ring around it and ejecting material along its spin axis as it settled into its blue supergiant mode. A similar phenomenon is well illustrated by the planetary nebulae MyCn18 - The Hourglass (as shown above). When it went supernova, the intense ultra violet radiation from the products of the supernova event illuminated and excite the old ejected materials around the star, causing them to lumeness.
  We have got to be a bit careful in interpreting what we are actually seeing here. The inner ring, a ring of denser material of generally fixed orbit, remains constantly irradiated, and thus continuously shines brightly. The outer rings however, are of much less dense material and represent two expanding cones of ejecta material, leading away from the central star. (Have another look at MyCn18 above to get the idea.) What is going on here is a bit different. It’s a strobe-flash effect. The strobe is the moment the supernovae went off with it’s intense burst of x-rays and ultra violet radiation. This intense burst would have faded within a few seconds. It would expand as a bubble around the exploding star, at the speed of light. This bubble would expand through the material of the bi-polar tenuous cones, causing two expanding rings to appear at the extent to which the intense wave-front had arrived to illuminate the material, and the light now reflected from that material, at the moment we observe it. So the two outer rings keep expanding away at the speed of light, getting dimmer over time, as the exciting radiation looses intensity by inverse square of the distance from the initial supernova.
  The inner ring however, remains to absorb all radiations of the remnant supernova, and will remain shining until it is dispersed and distorted by the arrival of the material ejected by the supernova event itself.
  Despite all the foregoing, there still remained a bit of a mystery, but this surrounds other physical observations of the event; the neutrino emissions. Leaving aside some technical minutia, it is reported that the SN 1987A event represented the beginnings of neutrino astronomy.
  In 1987 there were four principle neutrino experiments, of varying sensitivity, up and operating around the world. LSD = The Mont Blanc liquid scintillator (Mont Blanc, Russia, Italy); KII = Kamiokande II (Kamioka, Gifu Prefecture, Japan; with US support); IMB = IMB [Irvine-Michigan-Brookhaven] (Chicago, Illinois, USA); & BUST = BNO [Baksan Neutrino Observatory] (Baksan River gorge, Caucasus, Russia). Buried as they are, either under mountains or more usually in deep disused mines, to shield them from common cosmic background noise sources, these neutrino detectors were of new unproven technologies, prone to poor signal to noise ratios; as the investigators climbed up the learning-curve of understanding of their use. Even the neutrinos they were seeking, were not as yet a fully defined family of scientific entities.
  The neutrinos sought by these detectors are theorised to emanate from the complete dissociation of iron (Fe) atoms, or indeed the more compact neutronium atoms, when crushed or imploded by the extreme pressures due to gravitational collapse, or induced by shock for the neutronium, experienced in the cores of gravitationally induced type II collapsar supernovae. These neutrinos, theorised to be nearly but not completely massless, immediately pass hinderless through the mass of the collapsing star taking a supposed 99% of the events energy with them, at the speed of light, to shine brightly into a blind universe. They are the precursor messengers to the event, as it takes a not insignificant amount of time (hours) for candidate supergiant stars with radii of 100’s of millions of km/miles to collapse and rebound with the visible flash as their by-products radiate to announce the brightly optically detectable supernova event.
  SN 1987A, initially accidentally discovered by astronomers wondering around their great telescope in Chile, while taking a break in the night air, and who raised the international alarm of its appearance; was also some hours later spotted by an astronomer who missed the news in New Zealand; was the first and closest supernova in around 413 years (SN 1604), to be now available for scrutiny by comparatively modern astronomical instrumentation.
  Amid the excitement generated in the optical astronomical community, their neutrino colleagues had gone witless in puzzlement as they had earlier detected ‘something’ and had awaited confirmation of what they had suspected as a significant astronomical event. Based on a time frame more pertinent to neutrino astronomers, the SN 1987A event on the 23rd February 1987 is reported to have unfolded as follows.
  Some 9 hr 52 mins (2:52 UT) before optical sighting of the SN could be possible, the LSD (Russia, Italy) had detected significant neutrino activity. Some 5 hr 42 mins (7:35 UT) later, as simultaneous as it counts, the three other neutrino experiments KII (Japan, US), IMB (USA) and BUST (Russia) reported significant neutrino activity. Some further 4 hr 10 mins later, optical evidence of SN 1987A was deemed to have started. In the immediate scientific reports that followed the event, it was reported that a second neutrino event as also evidenced by the LSD, simultaneous with the KII, IMB and BURST detections, was of low probable significance (i.e. possibly noisy) and had to be discounted. The earlier LSD neutrino detection was deemed to have no relevance to the SN 1987A event and was discounted outright. Then everybody patted themselves on the back and congratulated themselves with the discovery of a rather unusual, but definitely type II collapsar event.
  It seems reckless and peer biased that the astronomical community should have accepted such short sighted reporting where 4 serious neutrino experiments, previously reporting, not a lot; should all 4 at around the same time (i.e. within a 10’s of hours time-frame) report neutrino activity relevant to a real supernova; and then discount the early activity reported from the LSD as being unrelated. As it turns out, that was a sad and misguided scientific omission.
Super-Kamiokande under Mt Ikeno
Super-Kamiokande under Mount Ikeno, Kamioka Observatory, Kamioka mine, Kamioka cho, Hida city, Gifu prefecture, Japan
Kamioka Observatory, Institute for Cosmic Ray Research (ICRR), University of Tokyo, by Nikken Sekkei

  It took some 18 years of further research into super-massive collapsar events, new stellar modelling, neutrino flavour physics and a bit of science history research to put together what was really detected in 1987, and what it means today. In a paper published by TAUP 2015 from the Russian Academy of Science, Institute for Nuclear Research (O G Ryazhskaya), some previously omitted things come to light.
  It turns out that the lead neutrino activity reported by the LSD (2:52 UT), was also recorded by KII and BUST. Further, but not surprisingly off the map due to it’s questionable signal to noise ratio, was a positive result, gleaned at the same time, from the unusual Geograv; a gravitational wave antenna (a cousin to LIGO) based in Rome. Also expressed is that the LSD detects a different flavour of neutrino than the detectors of KII, IMB and BUST. And current thoughts on type II collapsar modelling may be explained by a rotating collapsar model (RCM) which predicts a two-stage collapse; as recorded by all these instruments. How prescient could those first reporters have been had they included the lead neutrino activity of LSD, KII and BUST, just as a possible link to the SN 1987A event!

  tobagojo - 20170904
Super-Kamiokande under Mt Ikeno, Kamioka mine, Kamioka cho, Hida city, Gifu pf, Japan_2007
10 - Super-Kamiokande under Mount Ikeno, Kamioka Observatory, Kamioka mine, Kamioka cho, Hida city, Gifu prefecture, Japan; Update 2007
Kamioka Observatory, Institute for Cosmic Ray Research (ICRR), University of Tokyo, Higashi-Mozumi, Japan

  Specialists of the Kamioka Observatory, Institute for Cosmic Ray Research (ICRR), University of Tokyo, float on an inflated dingy on the ultra-pure waters of the Super-Kamiokande tank; checking some of the 11,129 inward-facing photo-multiplier-tubes (PMTs) that line it.
  The PMT array amplifies and tracks the photons generated by the neutrinos that react very rarely with the molecules provided by the 50,000 tons of ultra-pure water contained in a cylindrical stainless-steel tank (41.4m high & 39.3m in diameter). The rare traces of Cherenkov radiation that produces the light for the photosensitive area of the 20 inch (~ 50cm) detectors is guarded from cosmic ray interference by 1km of rock above the experiment; deep within Mount Ikeno.
  Free from dust, chemical ions, radio-active radon gas and bacteria that could otherwise spontaneously generate extraneous light, ultra-pure water (and air) is used for the experiment. Water purity of particles greater than 0.1 micrometer in size is reduced to 100 particles/cc as typical.
  To reduce further interference from the radio-actives within the mountains rocks; the surfaces of the entire excavated containment chamber is lined with a polyethylene material named Mineguard.
  Super-Kamiokande started construction in 1991 and saw first light on 1st April 1996. Some updates to the detectors was made in 2002, with further maintenance and computing facility updates in 2007-8.
  The facility networks worldwide to the astronomical community to alert them on significant neutrino events that may have been detected.
IC443 supernova remnant The Jellyfish Nebula in Gemini exploded 30,000 yr ago. Shock wave impacted on dust and gas - RGB - Don J McCrady_3227773708_c3a9891a8d_o_990w
10 - IC 443 Supernova remnant, The Jellyfish Nebulae, in Gemini. Exploded 30,000 yr ago. Shock wave impacted on dust and gas
RGB - Don J McCrady

NGC3372 - (Inside) Eta Carinae - AURA + NASA_AACHDCS0
10 - NGC 3372 - (Inside) Eta Carinae
AURA + NASA; Visualisation and object comparative spectra, courtesy Astronomy Today

  An X-Ray view of the Eta Carinae accretion disk is shown in the second image on the right. The lower HST image is shown in detail below.
NGC3372_03_(inside)_Eta Carinae luminous hypergiant star mass 100 to 150 M-sol luminosity about 4Meg-sol - HST - post outburst in 1841_990w
Return to Eta Carinae in the Carinae nebulae10 - NGC 3372 (Inside) the Great Nebulae of Carinae - Eta Carinae the luminous hypergiant star.
Mass 100 to 150 M-Sol, luminosity about 4Meg-L-Sol

  Eta Carinae, a rear and odd star, is considered one of the most massive and luminous stars known to modern science in our Milky Way galaxy. Being in the southern hemisphere, it was little studied until it was noted as a new star in the southern sky, in 1841. It remained the 2nd brightest object in the sky, nearly as bright as Venus, for about 2 years thereafter.
   It still remains a little unclear as to whether Eta Carinae is a new emerging star or a relatively young 100,000 year old hyper-giant coughing; the latter being the more accepted idea.
   What is unusual about it, is that its enormous mass puts it at about the upper limit in size for any star. Approaching the theoretical Eddington limit where the pressure of its radiative emissions is only just counterbalanced by the forces of gravity that hold it together as a star; its 1841 outburst may have been some concession to this theory. The normal development of a super-massive star suggests that it will have a very short lifetime, measured in millions of years, before it is expected to erupt as a supernovae. That it did not in 1841 suggests that it is still quite a young star, and that it has not yet arrived at the final stages of core nuclear-burning that will trigger that event.
   Theory further suggests that because the mass of Eta Carinae is larger than about 25 Solar masses, following its expected core-collapse (Type II) supernova event, the star will go beyond the formation of a neutron star and will collapse into a black hole. Because however we are still uncertain about the properties of mass-loss for aging stars, the uncertainty in theory about the final mass of Eta Carinae before going supernova, at present, limits the validity of this prediction.
   This HST image views the 1841 event some 150 years later, where highly developed bi-polar outflow of the systems accreting material is seen expanding away along the axis of a huge ring of matter surrounding the glowing star.
   @3000 pc distant, what we actually see here, was the condition of the star some 9,780 years ago. Astronomers estimate that the accretion process for this young star, began some 100,000 years ago.
V838 Mon an unusual outburst of an aging star_HST NASA, ESA and H.E. Bond (STScI) 2002
10 - V838 Mon an unusual outburst of an aging star
HST 2002 - NASA, ESA and H.E. Bond (STScI)

M1 - Crab Nebula_s10a_Supernova remnant in Taurus HST NASA ESA J. Hester & Loll (Arizina State Uni)_990w
10 - M1 - Crab Nebulae - Supernova remnant in Taurus
HST - NASA, ESA; J. Hester & Loll (Arizona State University)

M1 - Crab Nebula_s10b_Supernova remnant +Chandra X-Ray in Taurus HST NASA ESA J. Hester & Loll (Arizina State Uni)+CXC+ASU_990w
10 - M1 - Crab Nebulae - Supernova remnant + X-Ray in Taurus
HST + Chandra X-ray; NASA, ESA; J. Hester & Loll (Arizina State University); CXC ASU

M1 - Crab Nebula_s12a_Neutron star syncrotron radiation - Supernova remnant in Taurus HST NASA ESA J. Hester et al_2_650w-634h 10 - M1 - Crab Nebulae - Neutron star syncrotron radiation - Supernova remnant in Taurus
Chandra X-rays - NASA, ESA; J. Hester et al.
10 - M1 - Crab Nebulae - Combined X-Ray + Optical - Neutron star syncrotron radiation - Supernova remnant in Taurus
HST + Chandra X-ray; NASA, ESA; J. Hester et al.

  The central star within the small ring of the mouth of the 'bell' shaped image is the Crab 'pulsar'. A neutron star of diameter about 10 km that would not otherwise be seen except for and asymmetric magnetic field that accelerates charged particles in bi-polar directions, and collimates the light in a manor called the 'lighthouse effect'. One of these beams is pointed in our direction to be apparent as a pulse of light for each rotation of the neutron star. The opposite 'pole' of light is detectable more by reflection than direction, as only a fringe of the beam is detected. The Crab 'pulsar' has a period of 33 mille-seconds (1,818 revolutions per minute).
M1 - Crab Nebula_s12b_Combined X-Ray + Optical - Neutron star syncrotron radiation -Supernova remnant in Taurus HST NASA ESA J. Hester et al_650w-634h
10 - Caption

10 - Caption

Star Clusters

NGC2244 open cluster + Rosette Nebula in Monoceros - (No Filter) - DSS Consortium_02_990w
10 - NGC 2244 - Caldwell 50 - Open cluster + The Rosetta Nebulae in Monoceres
(No Filter) - DSS Consortium

  The Rosetta Nebulae is a conglomerate of molecular dust and hydrogen gas. In its centre, is a cluster of newly formed hot O-type stars, radiating strongly in the upper ultra violet that are clearing a hole in the middle of the nebulae. It is their radiation that causes the nebulae to be an emission nebulae.
The Rosetta nebulae over time has been variously assigned the NGC numbers: 2237, 2238, 2239, and 2246, to various of its parts. The number NGC 2244 is actually assigned to the Open Cluster of O-type stars. The nebulae is 5.2K-5.5K light years distant and has a diamater of ~130 light years; its material mass 10K(Minkowski 1949)-11K(Menon 1962) MSol.
NGC2244 open cluster The Rosette Nebula in Monoceres (H-alpha)RGB - Don J McCrady_3064492448_7d91ee6da0_o_990w
10 - NGC 2244 - Caldwell 50 - Open cluster The Rosetta Nebulae in Monoceres
(H-alpha) in RGB - Don J McCrady

  Viewed with the h-alpha filter; the pink glow of excited hydrogen throughout the nebulae is apparent; hence its name Rosette. The glow is driven by the radiation from the new cluster of O-type stars; but which stars?
NGC2244_Caldwell-50_Open Cluster_in Rosetta-nebula-in-Monoceros_close-view-of-cluster_HST_cfht
10 - NGC 2244 - Caldwell 50 - Open Cluster in the Rosetta nebulae in Monoceros. A close view of the cluster of bright O-type stars

10 - NGC 2239 - Star(s) in + NGC 2244 open cluster + The Rosetta Nebulae in Monoceres
(left) Jack Newton + (right) Spitzer Infra-red - NASA; JPL-Caltech, Z. Balog (Univ. Arizona, Univ. Szeged)

  This composite image, with the Spitzer ST deep seeing infra-red image on the right; establishes the cluster stars responsible for the central clearing or hole, and the H emissions, of the Rosetta nebulae. The 4 hazed O-type stars (+ one just out of view) are the newly formed cluster stars. All ‘white’ stars in the right image may be considered polluting stars from the field closer to the observer. The light blue stars, so imaged by the infra-red of Spitzer, are mostly young stars forming within the thin dust and gas of the nebulae.
  At this time, it remains a little unclear whether that brightest star on the left, which is the right star of the central bar of the cross on the right; is the star NGC 2244 or NGC 2239 (a mixed reference in the available data).
Aldebaran, the Hyades open cluster and the Pleiades in Taurus_Rogelio Bernal Andreo_PleiadesHyades_andreo50p_990w
10 - Aldebaran (red-giant), the Hyades open cluster and the Pleiades in Taurus
Rogelio Bernal Andreo

M45 - The Pleiades (Subaru) an Open Cluster in Taurus_Don J. McCrady_04_990w
M45_The Pleiades_Seven Sisters_Open Cluster_H-R_ @ ~120pc (AURA)_astronomy-today

- M45 - The Pleiades (Subaru) or the Seven Sisters, an Open Cluster in Taurus
Don J. McCrady

  The Pleiades are a young 100Meg year-old open cluster of metal rich stars, indicating that they are a group re-cycling the interstellar medium. The haze indicates that the group has recently formed from a nebulae of dust and gasses. The main stars are just visible to naked eye scrutiny where six or seven of the larger O-type stars (Seven Sisters) of the cluster are most prominent. Some of these O-type stars are just evolving off the Main Sequence and hence provide an age for the cluster.

   The myths proclaim that the ever amorous Orion was in pursuit of the Pleiades, the seven daughters (seven doves, seven sisters, Succoth) of Atlas the Titan god married to Pleione (but he had another woman with whom he had 5 daughters (The Hyades) and 1 son (Hyas)); whereupon the gods placed them among the stars to foil Orion, where he nightly stalks them across the sky.
Aldebaran and the Hyades open cluster in Taurus_Rogelio Bernal Andreo_PleiadesHyades_andreo50p_2_990w
10 - Aldebaran (red-giant) and The Hyades - Melotte 25 - Collinder 50 - Caldwell 41 open cluster in Taurus
Rogelio Bernal Andreo

Hyades_Open-Cluster_Melotte25_Collinder50_Caldwell41_in-Taurus_H-R_@46pc away - cut off ~Ty-A implying age of ~600Meg yr (AURA)_astronomy-today  The Hyades Greek Ὑάδες - Melotte 25 - Collinder 50 - Caldwell 41; is the nearest open cluster to the Solar System. @ 153 light-years (47 pc) distant to its core; with an age of about 625 Meg years. In the constellation Taurus, the brightest stars of the cluster form a traditionally associated ‘V’ shape together with the red giant Aldebaran, an unrelated but line-of-sight star, to the cluster
  A relatively young cluster of a few hundred stars, with some A-type stars already evolved to red giants, which are also now its brightest members; designated Gamma, Delta, Epsilon, and Theta Tauri. The core diameter of some 17.6 light-years (5.4 pc) is the most densely packed region; its.tidal diameter of 65 light years (~20 pc) will probably hold all the stars within it; where it is considered that about 30% of identifiable cluster members are outside this bound, and will eventually be lost to the cluster.
  Epsilon Tauri, also known as Ain, the ‘Bull's Eye’, harbors at least one gas-giant planet, discovered in 2007.
  The 6th letter of the Hebrew alphabet ‘Vav’, from a hieroglyph that looks like a tent peg; and with the metaphysical association of the neck of Taurus (The Bull) and throat ‘Chakra’; gives the ‘V’ shape to the Hyades cluster star sign; an asterism that traditionally associates the Hyades with the neck of Taurus in its zodiacal depiction for the constellation; which further extends to the Greek symbol ‘Ὑ’.
  In Greek mythology, Atlas the Titan god who fought the champion Olympians, and was so thus cursed to carry the heavens (not the ‘earth’ as some misconstrue) on his shoulders, had an outside woman who bore him 6 children; a son and 5 daughters. These daughters were the nymphs who on Mount Nysa in India, cared for Dionysius, the son of Zeus, in his childhood. Titan’s son Hyas was slain by a lion which caused great grief and tears (rain) from his dear sisters Phaesyla, Ambrosia, Coronis, Eudora, and Polyxo, that they adopted the name Hyades in his memory. The god Zeus, touched by the news of the sisters great sorrow, placed their image in the heavens as the Hyades, the ‘rain stars’; that rise to a zenith in the rainy season of the Mediterranean.
HyadesStarMap_Thuvan Dihn 20081013_marked 10 - Star Map of The Hyades Open Cluster; with the red giant Aldebaran (in line of sight only; although associated with the 'star sign' of the cluster, is not a cluster star and lies closer to an observer from the sol-system); Known stars are marked with the ‘V’ asterism of the Hyades cluster star sign

Adapted from Thuvan Dihn 20081013

10 - Hyades Open Cluster marked with the 'V' asterism of the star sign

Canon EOS Digital Rebel Xti; 20th December 2006, 20 frames @2sec each, F/5.6, 55mm focal length, ISO-400, at 7:36pm EST
Todd Vance.

Hyades Open Cluster (marked)_Canon EOS Digital Rebel Xti_20December2006_Todd Vance_Hyades_2
NGC884-chi-Persei+NGC869-h-Persei_H-R_Young 'Double cluster' ~13-19 Meg yr old (AURA)_astronomy-today

- NGC 884, chi Persei + NGC 869, h Persei; The double cluster in Perseus

NGC 884 - chi Persei (left) open cluster @7,600 light-years away; ~13 Meg years old

NGC 869 - h Persei (right) open cluster @ 6,800 light years away; ~19 Meg years old

NOAO AURA NSF September 1997; Burrell Schmidt telescope, Kitt Peak in south-western Arizona, Warner and Swasey Observatory, Case Western Reserve University; N.A. Sharp

  The relatively young open clusters chi and h Persei, named so by the Greek’s, who’s astronomer Hippocras first catalogued them in 130 BC, are observed to have an approach vector to the earth system of about 22 km/sec. They are designated to the constellation Perseus, but lie between Perseus and Cassiopeia.
  The young age of the clusters is noted from the bright O and B-type stars that stand out in the clusters and that are beginning to ‘turn-off’ from the main sequence; and some large red giants that have already evolved from their O-type progenitors; giving ages for the clusters of some 13-19 Meg years.
10 - M10 - Globular Cluster

Djorgovski-1_cluster_H+He-metal-poor_through-MW-bulge_HST_27June2011_ACS_(F606W-yellow-orange)coloured blue_(F814W-infra-red)red_990w
10 - Djorgovski 1 Globular Cluster; Hydrogen + Helium stars but unusually metal poor; seen through the bulge of the MW galaxy.
HST Wide Field Camer + Advanced Camera Surveys System; Combined exposure with 2 filters: F606W (yellow-orange)=coloured blue + F814W (infra-red)=red - 7th June 2011; ESA; Hubble & NASA

  Low in the hub of the Milky Way galaxy, the image is highly polluted with local stars; making analyses difficult. Its stars are mainly H + He with few other elements in its spectra, which may classify it as one with the lowest metallicities to be discovered. It is however typical of (closed = standard; as opposed to ‘open’ clusters of usually high metallicities) clusters with low luminosity stars and of low metallicity. Interest in the compactness of its core however, are of importance, but difficult to determine because of its low position in the MW core, and remains a challenge for future research.
M80-NGC6093 Globular cluster one of the densest @28 K lt-yr, 100k+ stars, ~15Gig yr old_HST_1July1999 NASA+THHT+STScI+AURA_GPN-2000-000930_990w
10 - M80 - NGC 6093 Globular cluster. One of the densest and perhaps oldest in the MW galaxy. @ 28K light-years away; with 100K+ stars; estimated age ~15Gig years old
HST 1st July 1999 - NASA + The Hubble Heretage Team + STScI + AURA (GPN-2000-000930)

NGC2808_Global-Cluster_3-generations-of-stars_HST_2May2007_ NASA+ESA+A.Sarajedini(Uni-of-Florida)+G.Piotto(Uni-of-Padua(Padova))_990w
10 - NGC 2808 - Global Cluster.
HST 2nd May 2007 - NASA; ESA; A. Sarajedini (University of Florida) & G. Piotto (University of Padua(Padova))

10 - NGC 7006 Globular Cluster.
HST 12th September 2011 - NASA

10 - M13 - NGC 6205 - The heart of the Great Globular Cluster in Hercules. About 300k stars; 25.1k light years away; Diamater ~145 Lt-Yrs
Filtered RGB - By Martin Pugh

  An aged star population where many of the stars have now evolved to red and blue giants (tints of orange and blue).
10 - NGC 6397 Globula cluster @ 8K5 light-years distant is one of the closest to earth viewers.
HST ACS - 17th August 2006 NASA; ESA; H. Richer (University of British Columbia, Canada)[heic0608a]

  NCG 6397 is one of the closest globular clusters to earth observers, and considered as old as the MW galaxy. Here we find a new view of the faintest red dwarf recorded to date. Red dwarfs in globular clusters classify as some of the oldest stars still on the main sequence (MS). With masses less than 1MSol, these stars which formed in the epoch of the cluster, will remain on the MS for some ~20 to 50 Gig-years before fading away; so here is seen a 13Gig7 year old example of this type.
  Of other stars, the dimmest white dwarfs recorded to date, have a different history. Stars between masses of around 2.2MSol to 8MSol will end their lives, having passed through a planetary nebulae stage of high mass ejection, as white dwarfs. Where in the low metallicity environment of a legasy global cluster like NCG 6397, the pre-white dwarf existance of the star will have consumed of the order of 0.60Gig to 0.40Gig years respective for mass; leaving a dim white dwarfs of around 13Gig-years old (max) on view. One can get excited about this, because 'dimmest' also excludes binary close-contact envelope exchange (which promotes blue stragglers), as the resulting white dwarfs would be brighter anyway.
10 - M53 Globular Cluster in the outer Halo of the Milky Way galaxy. Many blue stragglers have been found in this system which is rich in close binary, and higher order, orbits
HST WFC + ACS; Visible + Infra-red filters; NASA + ESA

M53 - Centre stars (Brightness reduced)
M53 - Outer stars (~ bottom left)
M53 - Blue stars at left of centre
M53 - Blue stars at right of centre
M53 Globular Cluster - White stars half way to the edge of the cluster.
10 - M15 Globular Cluster in Pegasus @ 32K light-years away; with an intermediate mass black hole of 4KSol at the core

HST 1998 - NASA + AURA (STSci-2002-18)
[Dimmed + contrast adjusted]

M15-G-Cluster in Pegasus 32 K-lt-yrs away-an IM-black hole 4KSol in core_HST1998_NASA-AURA-STSci-2002-18_450w_(dimmed+contrast-adjusted)
10 - M3 - NGC 5272 globular cluster in Canes Venatici
(Unknown sources) [Above and Below]

  NGC 5272 is one of the most intensely studied globular clusters in the MW halo, being in the northern skies, following M13; and being one of the largest and M3_bandm_334_gs_200_v03_350w brightest, following Omega Centauri (ω Cen). Discovered by Charles Messier on 3rd May 1764, to be designated M3, and resolved into stars by William Herschel at around 1784. Interest in the cluster grew after the American astronomer Solon Irving Bailey noted from 1913, a larger than usual population of variable stars in the cluster.
  It is now known to contains ~ 274 variable stars; by far the highest number found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation. M3 is considered a metal rich cluster, is the prototype for the Oosterhoff type I cluster, for medium abundance of heavy metals, in the range of –1.34 to –1.50 dex; a logarithmic abundance term relative to that of the Sun; showing an actual metallicity of 3.2 – 4.6%. Its high metallicity suggests that it is not a primordial cluster, being made from nth generation stars, and may have originated in the MW galactic disk before migrating to the halo; or a resultant cluster from a past galactic encounter of the MW galaxy.
  The estimated age of M3 is between 8 to 11.39 Gig-years; the latter being the currently accepted age; this is just ~ 2 Gig-years younger than the currently accepted age of the universe. This just means that the star population of M3 is quite old and mature; as directly indicated in the colour-magnitude (CM or H-R) plot alongside.
  The cluster is 33,900 light-years (10.4 kpc) away, with an apparent visual magnitude of +6.2, placing it at the edge of the limit to naked eye visibility. It is made up of ~ 500,000 stars and is estimated to mass 450,000 MSol in a volume some 180 ly in diameter. M3 is located about 31,600 ly (9.7 kpc) above the Galactic plane and roughly 38,800 ly (11.9 kpc) from the centre of the Milky Way galaxy.

47-Tucanae_NGC 104_H-R_Southern globular cluster age ~12 to 14 Gig yr oldest-known objects in the Milky Way Galaxy (ESO,NASA)_astronomy-today_0210 - 47 Tucanae - 47 Tuc - NGC 104 - Bennett 2 - C106 - Dunlop 18 - Lacaille I.1 - Globular Cluster in Tucana @ 16,700 light-years away; 120 light years across.
Credit: Dieter Willasch (Astro Cabinet)

  47 Tucanae is the second biggest (1Meg+ stars) and brightest (4.03 mag) globular clusters in the halo of the MW galaxy and is metal poor. 47 Tuc is approaching us at roughly 19 km/s, a component of its velocity towards us; as it curses its orbit in the galactic halo. One of the oldest clusters, estimated to be between 12-14 Gig years old; some of its aged stars are clearly seen as large red giants in the image above. HST surveys have registered many blue stragglers near its core; a product of many binary, and higher order star combinations, expected in the system.

  The bright 47 Tuc cluster has naked eye visibility and is highly evolved with stars in the instability strip (Cepheid variables), red giants, and the ashes of giants, many white dwarfs. As would be expected from this scenario, the leftover supernovae remnants, neutron stars have been detected. 47 Tuc boasts 23 millisecond pulsars; high speed rotating neutron stars that accreted material from a companion to speed them up, an attribute of binary systems; with one accreting system, 47 Tuc W, actually observed. The Chandra X-ray Observatory has detected most of these x-ray emitting neutron star systems. The Fermi Gamma-ray Space Telescope has also detected gamma radiation from some of the millisecond pulsars, making 47 Tuc the first globular cluster in which gamma pulsars were detected. As yet (2012) no black holes have been detected in 47 Tuc; although it remains a candidate for a <1,500 MSol intermediate balck hole.
  47 Tucanae, a cluster in the southern sky, was first noted by Nicholas Louis de Lacaille (Lacaille I.1) during a southern sky survey in 1751. It is next noted by Johann Elert Bode in a rather obscure catalogue "Allgemeine Beschreibung und Nachweisung der Gestirne nebst Verzeichniss" made in 1801. It was next noted by James Dunlop (Dunlop 18) in 1826 and then by John Herschel's southern sky survey from South Africa in 1834.
10 - An historic image of 47 Tucanae - 47 Tuc - NGC 104 - Bennett 2 - C106 - Dunlop 18 - Lacaille I.1 - Globular Cluster in Tucana.
ESO h-alpha 1986 1m Schmidt Telescope at the La Silla observatory in Chile. The telescope is now decommissioned.

10 - NGC 5139 - Omega Centauri (ω Cen) in the constellation of Centaurus. 15,800 light-years (4,850 pc) away; 150-230 light-years in diameter; 10+ Meg Stars; Mass 5 Meg MSol; ~12+ Giga years old.

  Omega Centauri was first listed some 2000 years ago in a catalogue by the Greek Ptolemy as a star. In 1677 the English astronomer Edmond Halley listed it as a nebulae; the astronomer Nicholas Louis de Lacaille included it in his catalog as number I.5 around the 1750’s; in the 1830’s the British astronomer John William Herschel was the first to recognise it as a globular cluster. The current name ‘Omega Centauri’ is a Bayer designation suggesting a star, not a cluster.
NGC5139_Omega Centauri_Gordon Mandell_320w  Omega Centauri is the largest, brightest and supposedly oldest globular cluster to orbit in the halo of the Milky Way galaxy. It is one of a family of some 200 globular clusters known to randomly orbit in the halo. All the stars are older than the sun; and all stars are considered as Population II, generally metal poor stars. But recent deductions suggest that Omega Centauri might be a dwarf galaxy, captured and stripped of its outer stars, in the past development of the MW galaxy.
NGC5139 Omega Centauri_H-R_Globular Cluster @5000pc+40pc in diameter (AURA)_astronomy-today   Reasons cited are based on some differences in some of its characteristics when compared to the standard , albeit smaller, globular clusters of the halo. Omega Centauri is 10 times more massive than the average globular cluster in the MW; it rotates comparably faster; resulting in an oblate globe of stars; the metallicity of its stars, though low, is contaminated with star processed elements (metals); and although very low in dust and gasses that would otherwise promote new star formation, appears to have a few generations of stars as its population, that suggests that the clusters population did not all form at the same time. In an earlier era, it was even suggested that a new Population III designation might need to apply to this type of cluster; but that hypotheses has, for the moment, been set aside. Where the argument for a captured evolved dwarf galaxy is compelling, not all astronomers are convinced, as some of these differences may be explained by careful consideration of the general behaviour of ordinary global clusters, in the light of new understanding of their properties.

Incert: Omega Centauri by Gordon Mandell.      

  In 2008 a Gemini and HST study of the core of Omega Centaur proposed through the motion study of stars in the core discovered to be moving at a faster orbital rate than would be normal, that a intermediate black hole resided in the core. In 2011 this was refuted by another HST core study that suggested that the differences in star motions were not found, that the first study was looking in the wrong place; and suggested that if an intermediate black hole did exist, its mass was now confined to a lower mass limit. So the speculated black hole in the core of Omega Centauri, should it exist, would have a mass of between 40,000 to 12,000 Msol; the lower mass being the preferred value.
10 - NGC 5139 - Omega Centauri globular cluster or dwarf galaxy closer view
HST 2nd April 2008 NASA ESA Hubble Heritage Team (STScI/AURA) A. Cool (San Francisco State Univ.) and J. Anderson (STScI)

  A view of the red giants and mature old stars in this old cluster.
NGC5139_Omega Centauri globular cluster_Central_Region_split_stars-01_HST_NASA_ESA_990w
10 - NGC 5139 - Omega Centauri globular cluster. The central region motion study.
HST WFC3 2002 – 2006 NASA/ESA J. Anderson and R. van der Marel (STScI)

  Using the HST to take colour-filtered images of the central region of Omega Centauri; NASA scientists took high resolution images of the same region in 2002 and again in 2006. Comparing the relative change in positions of the stars enclosed by the box shown; a 600 year plot of the relative motions of the selected stars was computed. The resulting motion trajectories are shown in the plot alongside. Incremental dashes in the motions represent steppes of 30 years each.

NGC5139_Omega Centauri globular cluster_Central_Region_split_600-yr-motions-01_HST_NASA_ESA_325w  Visible in the main filter-enhanced image are; the low temperature red super giants as red stars; blue stragglers, the A and B-type giant stars as blue; horizontal branch giant stars as orange. The rest of the stars are intermediate F stars moving away from the main sequence and approaching the rising giant branch; they will be the larger of the white stars. The smaller stars; orange, white and red, will be mainly stars still on the main sequence; intermediate between F and G-type, down to the red M-type stars. It is assumed that the H-R plot (or Colour Magnitude - CM - plot as astronomers would want to call it) may not have originated with the high resolution of the HST, and could be ground based, where the band of low luminosity stars down to the M regions of the graph, have not been fully represented.
  In the main, the H-R (CM) plot indicate an age for the cluster of around 4-5 Gig years (at turn off); somewhat at odds with the stated age of some 12-14 Giga years for this ‘old’ cluster.

  The blue stragglers are expected however, as many binary, and higher order star systems, are known to exist in globular clusters; which will rejuvenate stars to stragglers by mass-transfers in these systems.

  Again; by the upper bound age of the Omega Centauri cluster of 4-5 Gig years alone; expected are examples of fully evolved remnants of A and B-type stars, white dwarfs. Were for reasons given before these may not be represented in the graph; within this high resolution take by the HST; statistically, some of these stars should be present in the image as tiny white dots. If the age of the cluster is as stated as some 12-14 Giga years; some aged white dwarfs may have even turned to tones of deep orange or even light-reds; the deep reds being left to the still evolving red dwarfs on the bottom main sequence.

  Getting to see into the crowded heart of a large globular cluster estimated to contain over 10 Meg+ stars, seems a pretty astonishing achievement by the HST team. One is reminded and cautioned here that globular clusters are theorized to gravitationally compact their cores with large mass stars having ejected the low mass stars to higher orbits in the ‘halo’. So the stars one views in this core region, may be representatively only large mass stars; if this is truly the case, then 1.44 Msol white dwarfs, and certainly M-type red dwarfs, may be absent from this sample. However, this assumes an ejection efficiency of 100%; a more probable lesser figure, leaves a few small stars to be found in the core region.


Just 90 years ago, nobody realized what a galaxy was, although speculations in the 18th and 19th centuries had come upon the idea that ‘nebulosity’s’ in the sky could be collections of stars. The problem was two fold. The first part was that the telescopic instruments of that early period were not powerful enough to resolve ‘nebulae’ into any semblance of stars; and secondly, that there was as yet no reliable way to measure the distance to the ‘nebulae’. The Great Andromeda Nebulae (M31), as it was then called, was to provide that key to astronomers to open Pandora’s box to the real size of the universe.

 The American astronomer Vesto M. Slipher, an assistant to astronomer Percival Lowell, in 1912 using spectroscopy, discovered that virtually every ‘spiral nebulae’ he observed, had a red-shifted spectrum; they was receding from our Milky Way (MY) galaxy. It was noted that ‘spiral nebulae’ further away, had larger red-shifts. And so it rested; until E. Hubble put it together later. Incidentally, M31 is a bit of an oddity, it is blue-shifted, moving towards us; and will eventually collide with the MY galaxy.

 In 1917 the American astronomer Heber D. Curtis was investigating supernova in the Great Andromeda Nebulae, starting with the 1885 supernova ‘S-Andromedae’. On a search through photographic records of 11 novae in the ‘nebulae’, he noticed that the recorded magnitude of the outbursts, on average, was 10 orders of magnitude fainter than similar ‘novae’ in the MW. Curtis then set a distance to M31 of 150 Kpc (489.24 Klt-yr); 33% of the value that Hubble would estimate 12 years later. At this point however, Curtis became an adherent to the ‘island universe’ camp.

The story next turns to the Milky Way galaxy as the model used, before the 1920’s, as the whole extent of the universe. The American astronomer Harlow Sharpley was studying the distribution of global-clusters, using RR Lyre variable stars found in them, as ‘distance candles’. The two discoveries he made were; that the globular clusters are very distant from the sun, in the order of thousands of parsecs; and that once plotted in a 3-Dimnesional way, make up a huge ball 30 Kpc in diameter, with the sun not at the centre. He next made that intellectual connection that the ball of clusters must surround the MW galaxy, and the centre of the ball was the centre of the MY galaxy; and hence the universe. The centre of the galaxy was 8 Kpc away from the sun, in the direction of Sagittarius. But although Sharpley had moved the centre of the universe from galaxies_Radial-velocities-from-spectral-analyses_galaxies+Hubble-plots_adapted-from-astronomy-today_03the sun to the centre of the MY galaxy; he firmly believed that the ‘spiral’ nebulae, of which Andromeda was one, were all part of the Milky Way. Some report that he considered it beyond belief that the universe could comprise other structures, as large as the MY galaxy itself.

 The argument came to a head when, in April 1920, the topic of whether the ‘nebulae’ were just clouds of dust and gas within the MW galaxy, was taken to debate in public. H. Sharpley stood his ground that the MW was the centre of the universe; his opponent the American astronomer Heber D. Curtis, thought otherwise. Curtis countered with four principal arguments. The first, using a principal of conformity, stated that the range in size of the ‘nebulae’, about 10 to 1, if they were all the same size and the size of the MW; they would be up to 10 times more distant from the MW. The second; that looking into the area of ‘avoidance’ of the MW galaxy; i.e. towards its centre; there were fewer ‘spiral nebulae’ there, than looking in any other direction; If they were part of the MW, then more, not less, should be found. The third; was that pictures of ‘spiral nebulae’ showed bands or spirals of dust around the centre of the ‘nebulae’, obscured the view inside; wasn’t that the same as the area of ‘avoidance’ displayed by the MY galaxy; so the MY galaxy has dust obscuring its centre, and is just another galaxy. Finally; the spectra of ‘spiral nebulae’ was different from, for example the Great Nebulae in Orion (M31) with its gas type spectra; the ‘spiral nebulae’ spectra showed a bright background with many absorption lines, just the same as stars. And so the debate rested, with astronomers divided into both camps; because a firm distance yardstick was needed to settle the issue.

stars_Standard-Candles_Variable-Stars_RR-Lyrae_Cepheids_at_02 In 1922, astronomer Ernst Öpik gave a distance determination which supported the theory that the Great Andromeda Nebulae was indeed a distant extra-galactic object (No additional data available at this time).

Strong change came in 1929 when Edwin Hubble identified Cepheid variable stars, another type of ‘distance candles’, from photographs taken with the 2.5 meter (100 in) Hooker telescope at Mount Wilson and set the distance to the Great Andromeda Nebulae at about 450,000 parsec, or 1,500,000 light years away; well outside our local Milky Way galaxy.  This was good enough to settle any arguments to the contrary, that prevailed at the time.
In 1952 Walter Baade reviewed the standards set for RR Lyrae and Cepheid variables with respect to their application for the determination of the distance to M31. On examination of photographs from the 200 in Hale optical telescope at Mount Palomar in California, Baade found that the magnitude of RR Lyrae stars in the globular clusters did not match those set by current standards. He determined that a combination of misunderstanding, assumptions made with statistical parallax and the interstellar absorption which had been neglected, led to an underestimation to the magnitude of the Cepheids to have been set by an order of 1.5 mag too low. His recalculations virtually doubled the distance to M31, and in consequence, the accepted size of the universe; overnight.
These measures would again be
adjusted after the 1999 release of the Hipparcos (High Precision Parallax Collecting Satellite - ESA 1989 to 1993) data; that was 10 times better than ground based data, that recalibrated the Cepheid variables used for distance determination. The value of the distance to Andromeda that is accepted today, 2.54 ± 0.06 Meg light years; is some 69% greater than Hubble’s estimate, although some 80 years later.

 Hubble would formalize the work of the astronomer V. Slipher, together with his own data on red-shifts of ‘nebulosities’, to plot the data on a graph. He discovered a linear relationship; that the velocity of recession of the ‘nebulosities’, as determined from their red-shift, was directly proportional to their distance away from the Milky Way. The further away, the faster they were going. The universe appeared to be continually expanding. This discovery impacted on Einstein’s Theory of General Relativity, causing Einstein to regret having emplaced a fiddle-factor in his equations to restrain them to a ‘static universe’; where had he not done so, General Relativity could have predicted Hubble’s results. It is space-time itself that is understood to be expanding. The constant from his graph H0, became known as Hubbles constant, an apparent physical constant of the universe, and has ever since occupied astronomers for its correct interpretation and value; and a more accurate determination of its value was one of the prime objectives of the Hubble Space Telescope's mission of the 1990’s.

galaxies_Hubbles-tuning-fork-scheme-for-basic-galaxy-classification_02b In 1939 Hubble would develop a classification system for ‘galaxies’ based on their visual morphology. It is still used today, much modified, as a basic useful classification tool; but is understood to have nothing to do with a description of the true evolutionary morphology of galaxies.

What needs to be realized, is that Hubble’s determinations were a startling discovery, upsetting the ideas that the Universe comprised only the Milky Way; that the many curious ‘nebulosity’s’ were not planet forming ‘nebulae’ as many had greeted the beautiful photograph of Andromedae taken by Isaac Roberts in 1888 to mean; and caused the displacement of the term first proposed in 1755 by the philosopher Immanuel Kant that the ‘nebulosity’s’ were island universes of stars in their own right, into a completely different context.

 Hubble changed the paradyne. Great nebulae became accepted as ‘Galaxies’ and The Universe ended up holding everything. Hubble set roots to the science of Cosmology that today keeps many an astrophysicist and mathematician extremely occupied in developing theories that converge in providing an interpretation for its reason; and for a stable value, for Hubble’s Constant; a constant that might in the future prove instead to be a dimensional variable related to dark matter. However for now, it is a cornerstone unit of astronomy, that became Hubble’s legacy to science. Since it all started with Andromedae; such is the power of beautiful women.

M31-Andromedae_Photo of Nebula by Mr Isaac Roberts 23Dec1888_exposure 4 Hrs_enlargedx3-times_Cassel&CoLtd_Lith_London_r+90_990w
10 - M31 - Andromedae; Photograph of Nebulae by Mr Isaac Roberts 23rd December 1888
From his private observatory in Sussex, England - Exposure 4 Hrs Enlarged x 3 times; Cassel & Co Ltd, Lith, London, 1890 (scanned image)

  Spiral features are just about discernable in the image, together with the suggestion of stars in the ‘nebulous’ region. A small spiral galaxy (M110) is seen as a round haze under the bottom ‘axis’ of the rings. On the other side of the galaxy, to the left of centre, the brightest hazy object is a small elliptical dwarf galaxy called M32.
  Captioned as ‘Photograph of the Nebulae 31 M Andromedae’, one must realise that at this period, 'galaxies' had not yet been invented, and this ‘nebulous’ item was known as 'The Great Andromedae Nebulae'. Some sources suggest that the astronomer Mr Roberts still believed that M31 was a ‘nebulous’ collection of matter, accreting to form a planetary system; in keeping with the general ideas of the day.

  But less than two years later, in 1890, the literature is beginning to suggest that spectroscopic analysis of M31 was different from the spectra of glowing gasses as noted for the Orion Nebulae (M42), and was more suggestive of ‘a vast cluster of minute stellar points’. So the realisation that M31 was a 'galaxy of stars' was there beginning to settle in. This was also strengthening the idea of far stars where, the 'stellar points’ model matched the observations in helping better to explain the ‘Nova 1885’ observed near the centre of M31 in 1885; which was actually a supernova, (now known as ‘S Andromedae’). That would only occur if stars were present near the core of the 'nebulae'.
  One needs to be careful here (much hindsight of the intervening years applying - wow! a century) that the idea of ‘a vast cluster of minute stellar points’ was a correct interpretation for the day, however; what they were actually seeing in their photograph, were not stars, but collections of stars now known as super clusters. The resolution of their telescope, was still not capable of resolving 'single' stars at the distance of Andromeda. It would take about another 45 years before a good 'inference' of stars was visually seen, in the period of the 1930's; and another 60 years after that, to see the actual 'stars' with instruments like the Hubble Space Telescope and other large ground based telescopes of a future era.
10 - M31 - NGC 224 - The Andromeda Galaxy or The Great Andromedae Nebulae. (No filters) Normal light showing star clusters and dust emissions
DSS consortium

  M31 – Andromeda is a barred spiral galaxy of type SA(s)b as classified in the de Vaucouleurs-Sandage extended classification system of spirals; @2.54 ± 0.06 Meg light-years (778 ± 17 kpc) distant from the Milky Way and with a diameter at the widest point estimated to be 141,000 ± 3,000 light-years (43 ± 0.920 kpc) wide; with an estimated mass of 0.71 Tetra MSol; and when dark matter is included, to be about 1.23 Tetra MSol. 2006 data from the Spitzer Space Telescope estimates M31 to contain some 1 Tetra stars. M31 is the largest galaxy in the Local cluster together with The Milky Way and the Triangulum galaxy. The Local cluster, which contains around 45 or so other smaller galaxies; where M31 is not the nearest of them to us in the Milky Way, but is the closest galaxy that is similar in size and shape to our own Milky Way Galaxy.
   Named after the constellation in which it is found; Andromedae was the legendary beautiful daughter princess of Aethopia, whose father was king Cepheus and mother Cassiopeia. Jealousy over her beauty had her chained for sacrifice before a dragon to assuage the gods; whereupon Perseus heroically slew the dragon and carried her off as his wife.
  Astronomical history notes that the first observer to describe Andromeda was the Persian astronomer Abd al-Rahman al-Sufi, known in the West as Azophi, who describing it as a ‘small cloud’ in around 964. Star charts of that period have it labeled as the Little Cloud. It was then telescopically observed by the German astronomer Simon Marius on 15 December 1612. In 1764 the French astronomer Charles Messier entered it as object M31 in his catalogue of 109 brightest of celestial objects with a nebulous appearance. In 1785 the British astronomer William Herschel and his sister, in the course of their survey of the sky that eventually produced a catalogue of over 5,000 nebulae, considered M31 to be the nearest of all the ‘great nebulae’ and observed a reddish hue within the core region. They however seriously underestimated its distance at no more than 2,000 times that to Sirius (5,400 pc; 17.6k light years), based on M31’s color and visual magnitude. In its context, this was not a bad estimate, as the object M31 was still being treated with the understanding of the day, as some manifestation of a ‘star’.

  Here we go again with 'cautions' about seeing 'stars' in Andromeda. This beautiful image taken with a modern telescope in the visual spectrum, actually resolves no 'stars' in Andromeda. First of all, most of the round dots of light in the image are polluting stars interveaning from our own galaxy, the Milkey Way. What may be dots of light associated with Andromeda, rather confusing to sort out visually (but spectrascopy and doppler shift measurements would do it), as they are present nonetheless, are 'star clusters'. The white 'haze' on the other hand, are the 'inferred' stars. The following infra-red image makes the point.
10 - M31 - NGC 224 - The Andromeda Galaxy in h-alpha infra-red.
Wide-field Infrared Survey Explorer (WISE) (Filter h-alpha) infra-red; NASA, Don J McCrady

  This filtered image in infra-red, is a little more 'telling' as to which 'dots' belong to Andromeda. The infra-red, longer wavelength than the visual spectrum, sees through the dust, showing more detail of the inner regions. Firstly; all the pink dots, mainly accociated around the outer spiral dust lanes, are young 'star clusters' forming in the dusty and hydrogen rich (the h-filter ='pink' = hydrogen ions) regions of the galaxy. Secondly; all the bluish-white smudges, also associated with the dusty lanes, are active areas of star formation with mature young 'star clusters' of A and O type stars. Again, no 'stars' are visable in Andromeda, only 'inferred' by the white haze.
10 - M31 - NGC 224 - The Andromeda Galaxy in ultra-violet; shows blue regions containg massive young star clusters.
GALEX (Filter 3) ultra-violet

  Getting better at showing what belongs to Andromeda, this ultra-violet image is selected to show hot bright regions in the galaxy, looking for sources of star formation. It shows more clearly, star clusters in the spiral regions of the galaxy. But still no 'stars' in Andromeda.

Patches through a Straw

  We notice in this revealing image of M31 (NGC 224), The Andromeda Galaxy, by GALEX; that it is a composite of a number of circular fields imaged by a large telescope. Where it is (later) commented - looking through the ‘straw’ of the visual field… (See Hubble Deep Field South (HDF-S)) – is a reference to the fact that it is not a trivial exercise in finding Things in the Sky. Therein lays the importance of compiling catalogues that provide accurate information on the position and the type of objects to be found in the immensity of that ‘outer space’; an exercise recorded to have begun by the Greek astronomer Hipparchus of Nicea in 130 B.C., some 2,000 years ago. Through the ages, Asian, Chinese, Japanese, Indian, Arabic, Aztec and other astronomers (perhaps more suited at the time to be: Philosophers, Priests, Numerologists, Polymaths, Courtiers, Astrologers, Oracles, a few Astronomers and some Charlterans as well!) began the task. It has been calculated, for the size of the human eye-lens, that only about 6,000 objects, world wide, are visible in the sky to the naked-eye observer; good enough for navigational reference for which the stars were mostly used in earlier times; but the implications from the haze of the Milky Way, suggested that there was a lot more ‘out there’ than could be seen. It was only with the popularisation of the telescope by Galileo Galilei in about 1610 that the problem of charting the sky really began. Some noted pioneers were Nicholas Louis de Lacaille (1751), Charles Messier and Pierre Méchain (1764 ~ 1781), William and Caroline Herschel (1785), Johann Elert Bode (1801), James Dunlop (1826) and John Herschel’s Southern sky survey (~1834).

  To illustrate this problem, many authors of astronomy write their own versions of the following comment; but in 1890 Sir Robert Stawell Ball provided an informative, endearing and enduring account, that follows here.

 Note: Pagination is noted in square brackets e.g. [451] etc.

The Herschel Sky Survey

The systematic study of the nebulae may be said to have commenced with the colossal labours of William Herschel at Slough. The scheme which Herschel proposed for this task was a comprehensive one. He determined to make a survey of the entire heavens with a powerful telescope, and to note the objects of interest which he could detect. But though we can thus summarily describe the undertaking, yet a little reflection will show the gigantic amount of labour which it entailed. Considering how rapidly we can sweep our eyes over the heavens, it might seem a very easy matter to turn a telescope to one spot after another, until the whole sky has been reviewed. The two cases are, however, as different as possible; a glance of the eyes takes in an enormous region of the heavens, while the field of a large telescope only includes a comparatively small region. This is a point which often surprises those who for the first time look through a large telescope. Beginners sometimes expect to see the whole northern hemisphere, and perhaps the signs of the zodiac, at the same time. It is even unreasonable to ask to be shown the Great Bear in a large telescope; the telescope can be pointed to special parts of the constellation, but if we want a comprehensive view of the whole, we must take an opera-glass, or something of that description, not a great and powerful instrument. A large telescope will hardly show even the whole of the moon at once. When we look through the eye-piece, we find the entire field filled with the brilliant body of the moon, and it will be necessary to move the telescope a little up and down, and a little to the right and to the left, in order to bring the whole surface of the moon under review. The moon occupies but a small portion of the sky; yet small as that portion is, the field of view in a large telescope is not so great. Suppose the entire surface of the heavens to be covered over with moons quite close [450] together, the apparent size of each being the same as that of our moon, the heavens would then form a mosaic of about 200,000 pieces. Assuming that a great telescope can show about half of the moon at once, the whole surface of the heavens would form about 400,000 fields of view. In such an instrument a complete survey of the heavens must therefore involve no less than 400,000 examinations of what the telescope can reveal in one view. This estimate includes the southern heavens; if we confine our thoughts to that portion of the heavens which is visible from these latitudes, we may perhaps say that about a quarter of a million fields of view have to be carefully examined. The scheme, then, which Herschel sketched out for his labours at Slough involved bringing a quarter of a million fields under review; it will readily be believed that considerable organisation was necessary to enable so vast an undertaking to be accomplished. It was necessary to provide that none of the fields should be allowed to escape, and that none should. be observed more frequently than was necessary.

But there is another way by which we can obtain an adequate conception of the enormous labour which Herschel contemplated, and which he lived in great part to complete. Instead of counting the number of fields of view which he would have to examine, let us form an estimate of the number of objects that would be likely to come under his notice. We need hardly say that such an estimate must be only an approximate one, but for the purpose of conveying to the reader some idea of the extent of Herschel’s labours it will be quite sufficient. There are several different classes of objects in the heavens, but the objects which arc most numerous and most characteristic are the fixed stars. The constellations, with which every one is familiar, are formed of fixed stars of every conceivable brightness, from the splendour of Sirius down to the merest point of light that can be discerned in the most powerful telescope. Stars can be found of every tint, from the red at one end of the spectrum to the blue at the other, and they are scattered in boundless profusion over the whole extent of the heavens.

Suppose that a great telescope like that which Herschel used in his researches be employed for the purpose of’ counting the [451] stars, each one of the 250,000 fields of view would have to be regularly inventoried. In almost every one of those fields of view some stars would be seen; in many fields there would be a large number of stars; while in others the stars would swarm in abounding multitudes.

Immediately after Herschel and. his sister had settled at Slough he commenced his review of the northern heavens in a systematic manner. For observations of this kind it is essential that the sky be free from cloud, while even the light of the moon is sufficient to obliterate the fainter and more interesting objects. It was in the long and fine winter nights, when the stars were shining brilliantly and the pale path of the Milky Way extended across the heavens, that the labour was to be done. The great telescope being directed to the heavens, the ordinary diurnal motion by which the sun and stars appear to rise and set carries the stars across the field of view in a majestic panorama. The stars enter slowly into the field of view, slowly move across it, and slowly leave it, to be again replaced by others. Thus the observer, by merely remaining passive at the eye-piece, sees one field after another pass before him, and is enabled to examine their contents. It follows, that even without moving the telescope a long narrow strip of the heavens is brought under review, and by moving the telescope slightly up and down the width of this strip can be suitably increased. On another night the telescope is brought into a different position, and another strip of the sky is examined; so that in the course of time the whole heavens can be carefully scrutinised.

 Herschel stands at the eye-piece to watch the glorious procession of celestial objects. Close by, his sister Caroline sits at her desk, pen in hand, to take down the observations as they fall from her brother’s lips. In front of her is a chronometer from which she can note the time, and a contrivance which indicates the altitude of the telescope, so that she can record the exact position of the object in connection with the description which her brother dictated. Such was the splendid scheme which this brother and sister had arranged to carry out as the object of their life-long devotion. The discoveries which [452] Herschel was destined to make were to be reckoned not by tens or by hundreds, but by thousands. The records of these discoveries are to be found in the “Philosophical Transactions of the Royal Society,” and they are among the richest treasures of those volumes. It was left to Sir John Herschel, the only son of Sir William, to complete his father’s labour by extending the survey to the southern heavens. He undertook with this object a journey to the Cape of Good Hope, and sojourned there for the years necessary to complete the great work.

 As the result of the gigantic labours thus inaugurated, there are now three or four thousand nebulae known to us, and with every improvement of the telescope fresh additions are being made to the list. [453]

Ball, Sir Robert Stawell; LL.D.; The Story of the Heavens; Book 5; Cassell & Company Ltd; 1890.

10 - Spitzer Space Telescope - An Infra-red Space Observatory
NASA, JPL, Caltech

  The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), was renamed post-launch after Lyman Spitzer, a noted scientist of the 20th Century, cited for his pioneering contributions to rocketry and astronomy, and on his articulation on the advantages and benefits to be realized from a Space Telescope Program.
  The Spitzer ST was launched from Cape Canaveral Air Force Station, on a Delta II 7920H ELV rocket, on the 25th August 2003, with an onboard liquid helium supply for cryogenic cooling of its indium antimonide doped silicon infra-red detectors.

  The observatory was placed in heliocentric orbit, trailing and drifting away from Earth's orbit at approximately 0.1 astronomical units per year (a so-called "earth-trailing" orbit) to minimise heat-load emitted by Earth, and had an initial mission expectation of 2.5 design years, with 5 years of possible ‘cold mode’ operation from available cryogenics. If still functional; it could then operate in ‘warm mode’ with limited capacity. In operation, the SST ran out of LHe cryogenics on the 15th May 2009; 9 months beyond ‘cold’ expectations; and operated thereafter in ‘warm mode’.

  The Spitzer ST primary mirror is 85 centimetres (33 in) in diameter, made of beryllium, cooled to 5.5 K (−449.77 °F) in ‘cold mode’ operation.

Its instrumentation includes:
  IRAC (Infrared Array Camera), an infra-red camera which operates simultaneously on four wavelengths (3.6 µm, 4.5 µm, 5.8 µm and 8 µm). The two shorter wavelength bands (3.6 µm & 4.5 µm) remain productive after LHe depletion in 2009, at the telescope equilibrium temperature of around 30 K, so IRAC continues.
  IRS (Infrared Spectrograph), an infrared spectrometer with four sub-modules which operate at the wavelengths 5.3-14 µm (low resolution), 10-19.5 µm (high resolution), 14-40 µm (low resolution), and 19-37 µm (high resolution).
  MIPS (Multiband Imaging Photometer for Spitzer), three detector arrays in the far infra-red at 24 µm, 70 µm, and at 160 µm.
10 - M31 - NGC 224 - The Andromeda galaxy in infra-red
Spitzer ST 25 August 2004, 24 micrometres infra-red; NASA, JPL, Caltech; K Gordon University of Arizona

  Now seeing through the dust with the infra-red filter, a clearer and more detailed view of the active inner spiral regions of Andromeda is seen. Filtered in the lower infra-red and with a space telescope, the stars within the dust regions themselves are now visable. All very hot sources will remain brighter than just the general stars; hence the bright regions of this image match those shown in the ultra-violet (above), but more detail will appear in the infra-red. The resolution again is of clusters of stars in the spiral arms of the galaxy.
  To give some more detail; a high resolution 'slice' of this infra-red image is shown below.
M31-NGC224_Andromeda galaxy_infra red spitzer ST_Ssc2005-20a1_ad_990w
10 - M31 - NGC 224 - The Andromeda galaxy in infra-red
Spitzer ST 25 August 2004, 24 micrometres infra-red; NASA, JPL, Caltech; K Gordon University of Arizona

  A 990 pixel wide, full resolution, slice of the Spitzer 8,193 pixel wide (by 2,410h) infra-red image of M31 is displayed above. Seeing through the haze and dust, this slice shows what appears to be the remnant of a dwarf spiral galaxy 'cannibalised' (an unfortunate term in popular usage by astronomers to describe this type of observation) by M31. The swirl of the dwarf can be seen against the backdrop of the near-side ring of stars.

  This higher detail 'slice' allows a closer view of the inner workings of the galaxy; but again one is cautioned, only star clusters are visable; still no 'stars' in Andromeda. Even with the impressive resolution of this digital image, each pixel represents a square that approximates a staggering 17 light-years per side (~3 x The distance between our local star the Sun and its nearest neighbour star α-Century [4.5 lt-yrs]); on the plane of Andromeda's view. Most round dots seen in these images, appart from those obvious features of high activity within the dust lanes of the galaxy, are polluting stars from our own Milky Way galaxy.

  To see the 'stars' in Andromeda, have a look at 'The stars in the halo of Andromeda' image.
10 - A view towards the centre of the local Milky Way Galaxy from Earth
DSS Consortium
[An image comperssed by the web page - Click 'View image' to get a larger look]
  An inverted (non conventional) view of the Milky Way Galaxy (MW) as seen from Earth. The sun resides in one of the spiral arms of the MW galaxy, so we have a limited view of the centre as there is a lot of molecular dust and gas in the way. The sun is situated about 66% away from the centre, along the disk plane of the galaxy. The dusty areas, where the stars are obscured, is concentrated in the compression waves that promote the spiral arms originating from around the centre of the galaxy.
  Because of the position of the sun, there is only a limited view we can get of the MW galaxy, as its spiral arms extend around and behind us. Our view of the MW galaxy is thus distorted, as the wrap-around is projected on a flat image, and contains some of what is behind us. The image shown is about 80% of the total wrap-around field; with the main focus towards the centre of the MW. We can more easily see through this dust and gas with radio telescopic instruments; however long infra-red instruments can see into the core, but are limited to very hot and energetic sources.
10 - A closer view towards the centre of the local Milky Way Galaxy from Earth
DSS Consortium

  An inverted (non conventional) view; Top = South pole.
galaxy_Milky-Way-structure+arms_9June2007_derivitive-by-Rursus_adapted-by-tobagojo@gmail.com_set_02b_450wObserved Structure of The Milky Way Galaxy
Source: 2nd derivative by Rursus 9th June 2007; 1st derivative by YUL89YYZ; Ctachme, Kevin Krisciunas, Bill Yenne The Pictorial Atlas of the Universe, page 145 (ISBN 1-85422-025-X) and µOR

  From a viewpoint of Galactic North, the observed spiral arms and disk structure of The Milky Way Galaxy is sketched; with the currently accepted names for the arms and structures. The sun – Sol – is shown located in the Orion/Cygnus arm (yellow) of the MY galaxy, with radiating spokes that are named with the abbreviated letters of the constellations to be found when viewed from the Sol-system, along that direction.
galaxy_Milky-Way_stylised-face-and-edge-view-of-the-disk_set_02_450h  The diagram illustrates that our view of to the centre of the MY galaxy is dominated by the stars and dust of the Carinae/Sagittarius arm; which is also the predominant feature in the views of the Central MY shown above and below this image.
  The Centre of the MY is shown as a red dot, with the outline of the bulging ‘bar’ of the spiral depicted in orange. Again, clearly depicted, is that to view the Centre of the MY, astronomers need to use instruments that can penetrate through the stars and dust of four intervening arms of the spiral and through the crowded stars of the ‘bar’ to see it.
  Dashed strokes indicate areas difficult to observe directly and have been extrapolated from existing data. A new feature of stars and dust (light blue) was discovered and added to the plot around 2007.
    Excited doubly ionised hydrogen (H II) regions are marked as coloured highlights in their respective spiral arms. The three sizes, donate their excitation parameter U:
  • Small - U > 200 pc cm-2
  • Medium - 200 > U > 110 pc cm-2
  • Large - 110 > U > 70 pc cm-2

Stylised face and edge view of the disk of the MY galaxy illustrating the position of the galactic halo stars and the globular clusters found around the galaxy.

Images of the central region of the Milky Way Galaxy viewed from Earth
Shown in different ranges of the electromagnetic spectrum - An inverted (non conventional) view; Top = South pole
galaxy_Centre-of-MW-galaxy_short-servey_03_IRAS infra-red reprocessed_450w
Visual - Digital Sky Servey (DSS)
IRAS - Infra Red Astronomical Satellite - Infra-red reprocessed
galaxy_Centre-of-MW-galaxy_short-servey_05_Hydrogen Alpha FSS_450w
galaxy_Centre-of-MW-galaxy_short-servey_02_SFD Dust Map infra-red_450w
Hydrogen-Alpha Full Sky Survey (FSS)
SFD - Dust map infra-red
galaxy_Centre-of-MW-galaxy_short-servey_04_2Mass infra-red_450w galaxy_Centre-of-MW-galaxy_short-servey_07_ROSAT All Sky Servey x-ray_450w
Two Micron All Sky Survey (2MASS) - Infra-red
ROSAT - All Sky Servey in X-Rays
10 - Black holes and other things at the centre of the local Milky Way Galaxy from Earth - An inverted (non conventional) view; Top = South pole
DSS Consortium

  The advantage of investigating the centre of the MW through the dust and gas with radio telescopic instruments, which operate at electromagnetic frequencies that pass through it, is limited on the other hand by what can be interpreted from these frequencies. What these radio telescopes will detect, is sources that emit strongly in the micro wave part of the spectrum. This again is limiting, as there are not that many things that will generate these frequencies. What will, are highly energised charged particles and charged particles moving in highly intense magnetic fields. So we expect to see shock fronts where radiation and matter are colliding; fronts where matter and matter are colliding; outlines of magnetic fields where charged particles (electrons and ions) are accelerated to sub light speeds; and fast moving super hot plasmas; and that’s about it. And all this on a gross scale, in orders of magnitude of about half an astronomical unit (AU), so that it can be resolved by the telescope. And of high enough intensities so that it gets through the gas and dust in the way. So whatever we expect to find in the centre of the MW, has got to be comparatively huge; and hugely energetic. This is exactly what we find in the Sagittarius A complex at the centre of the MW galaxy. A radio view is inserted in the above image.
10 - Supernova remnants, merging black holes and a suspected central black hole in the Sagittarius A complex at the Centre of the Milky Way Galaxy
90cm Radio - T.J.W Lazio (NRL); J. Imamura (TJHSST); D.G. Briggs (NRL); N.E. Kassim

  SNR = Supernova remnants; Sgr = Sagittarius. A feature called Sagittarius A West or Sgr A* (not shown) is embedded in Srg A (See below).
10 - The composit includes an inset of the emissions from Sgr A* [west](6cm Radio) in the bright spot called Sgr A for comparison.

90cm Radio - T.J.W Lazio (NRL); J. Imamura (TJHSST); D.G. Briggs (NRL); N.E. Kassim
galaxy_s04a_Sgr A West 3.6cm (Radio)_Farhad Yusef-Zadeh+Mark Wardle_NRAO_MW_08BA_450w galaxy_s04b_Sgr A 6cm (Radio)_Farhad Yusef-Zadeh+Mark Wardle_NRAO_MW_08B_450w
10 - The Sagittarius A west complex = Sgr A*; (in Radio) at the centre of the Milky Way Galaxy
3.6cm (left), 6cm (right) Radio - Farhad Yusef-Zadeh, Mark Wardle - NRAO

  In the centre of Sgr A* is concluded (1998) to be a large mass. The mass has initially been set as ~2 x 106 MSol; a black hole with a Schwartzschild radiusrs = 2 x 10-7 pc (6.17 x 106 km; 3.83 x 106 mi), 8.816 rSol.
  This is a commendable achievement of observation and a compelling conclusion, and is based on accessible data from a specific region of Sgr A*. But there are other features in Sgr A* and of Sgr A which leads to further possible conclusions. Probably a little to early to tell; but one suspects that there are more than one black holes in Sgr A*, probably of intermediate mass size, ranging from around 10 to 1000 MSol; and equally so in other areas of Sgr A.
The genesis of Gravitational Wave Astronomy

Ref: Ripples of Curvature - Kip S. Thorne

Joseph Weber 1975 with his prototype gravitational wave detector by James P Blair, National Geographic Society_BH-TW-Kip S Thorne-pg368  It all started with an engineering graduate of the U.S. Naval Academy of 1940, whom with some arduous service in the U.S. Armed forces, survived WWII to later complete a Ph.D in physics, with instruction from Karl Herzfeld, a mentor of the prodigal mathematician John Wheeler. After a year of actually working with Wheeler and his team, Joseph Weber was well versed in Einstein’s theory of relativity and the properties of gravitational waves.

Joseph Weber (1919 - 2000) in 1975 with his prototype gravitational wave detector made with a 2 meter aluminium bar, 1 meter in diameter, with piezoelectric strain gauges.
By James P Blair, National Geographic Society; Black Holes & Time Warps, Kip S Thorne, Pg 368

  In 1957 Weber began a rather lonely course of research in the theoretical exploration of how to instrument gravitational wave detection. By 1959 Weber considered that he had gathered sufficient data to begin construction of prototype detectors. Through the early 1960’s to the early 1970’s, Weber became famed for his large aluminium bars instrumented with strain-gauges, as the early pioneer of gravitational wave detection and research.

  Weber, generally famed as the father of gravitational wave detection, suffered the general criticism of actually having not detected any gravitation waves at all!

  Much of the disquiet arose after the attention Weber had drawn to the new field caused some enquiring scientists to question his methods and experimental practices as their own theoretical analyses and duplication of his experiments, had led them to null results. They then deemed that his equipment was not sensitive enough to detect gravitational waves, or that the experiment itself was ill suited to the purpose. Even the relativist Thorne himself and researcher Rainer Weiss were doubtful that Weber had ever detected anything.

  At first hand, though compelling, their arguments had the hallmark of some general scientific conceit; as some could argue that Weber’s equipment was sensitive enough to detect ‘close’ gravitational events, the likes for which there were no other investigators of his era equipped to detect. An inspiral of intermediate mass merging black holes in our Milky Way galaxy (though perhaps statistically of low probability) for example, or similarly rotating close binary neutron stars (which were the then considered candidates of that era), would have likely stimulated Weber’s detectors.

  Another default argument can arise in Weber’s favour when taken from an observational standpoint. Where on the one hand, supernovae or merging binary neutron stars are deemed optically observable; where on the other hand, merging binary black holes are not. Nobody was seriously looking at anything Weber could have detected; at that time there were no networks of communication alerts established around his type of research; nor more obviously, was Weber equipped with sufficient apparatus to provide triangulation of significance to accurately identify the locality of any remote disturbing sources.

Joseph Weber at the University of Maryland with an aluminium resonant gravitational-wave detector bar.  
University of Maryland Libraries, Special Collections and University Archives; Science  

Joseph Weber_Aluminium resonant GW detector bar_Special Collections and University Archives, University of Maryland Libraries_science-sn-weber_1280w_720h  The irony here is that with the usual vision of 20/20 hindsight, Weber’s failure can better be explained from the research and developments that he himself inspired for a future era.

  It may now be interpreted that Weber, though making a gallant attempt, truly failed because his apparatus did not uncouple from space-time, in that it could not detect the gravitational waves that passed through it; as both the ‘bar’ and its sensors were simultaneously distorted by the passing gravitational waves it was supposed to detect; thus leading to a null result.

  The advantage of the configuration of an optical (electromagnetic) orthogonal (or similar) interferometer is that the path of the photons themselves provide the decoupling to space-time from the mechanics of the instrument itself, thus allowing a credible (though extremely difficult) measurement of a gravitational wave to be made. With the added difficulty that the returned output would only be half the amplitude that might at first be expected.

  Despite all criticism, Weber remains the founding father of gravitational wave research as his work literally inspired 100’s of budding gravitational wave investigators. Being a bit of a hard nut; Weber was an optimistic loner till the time of his death, 30th September 2000.

  UpDate: tobagojo - update 20171006

LIGO_Caltech Media_Kathy Svitil_ref-beckett_L1_HiResLivingston_5B_r0.50-br-NR-shp_1920w_1080h
  LIGO - Advanced Laser Interferometer Gravitational-Wave Observatory - L1 (Livingston)
  A view of one of the 4 km-long (2.5 mile) arms of the US National Science Foundations Advanced LIGO Facility, Livingston, Louisiana, USA. LIGO uses a Dual Recycled, Fabry-Perot Michelson Interferometer (DRFPMI) developed collaboratively at GEO600.
  From Caltech Media, Kathy Svitil. Ref-beckett.

The Song in Space-Time
The Story of the First detection of Gravational Waves
  Learn the Song  (With a slight West Indian flavour!)

  We in TT like song-forms, we invented some of them. They are deep-rooted in our Caribbean culture. The lyrics of our calypso, soca and chutney brighten our carnivals; and parang our Christmases, and some of those in turn get played on our indigenous steel drums by many of our culturally specific TT steelbands. However, curiously similar to our penchant for odd music-forms, at the 2015 updated Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO 2015), over 1,000 highly skilled and committed technicians, engineers and scientist were also looking for a song-form. Albeit a theoretical song-form that they called ‘chirps’. These ‘chirps’ were not easy to invent. They were all the product of analyses of Einstein’s relativistic field equations that he developed in 1916 when he postulate the existence of gravitational waves, a year after he had composed his theory of General Relativity. Much later work by Kip Thorne in 1993 used the equations to describe how closely rotating binary black holes would generate strong gravitational waves, and how these waveforms would peak when the black holes eventually collided. That is the form of the ‘chirp’. From that time, to the refit at LIGO in 2015, these equations have been programmed into super-computers to realise the behaviour of as many interacting exotic cosmological heavy mass objects as the astrophysicists could think of that make all flavours of gravitational wave ‘chirps’. A ‘chirp’ being the audio translation of a specific type of detectable gravitational wave event.

  It was in the late 1950's when Joseph Weber began his lonely course as the pioneer of gravitational wave research. By the mid 1960's, he had begun to inspire many researchers, but the expected results were not convincing, even into the early 1970's. However, by the mid 1970’s gravitational wave research was beginning to be taken seriously and proposals for a serious project to accomplish the feat arose in the mid 1980’s. It had now taken over 40 years of research into the intricate mathematics of Einstein’s general theory of relativity and the technical development and understanding of may new materials and technologies, across all disciplines of engineering and the sciences, to make all the equipment to find and to arrive at the templates for, a meaningful gravitational wave ‘chirp’. The LIGO Scientific Collaboration, which now included some 1,004 noted members from 15 contributing nations, and 133 internationally significant scientific institutions, having over the past years upgraded their LIGO facilities, were now ready to look for this odd song. The ‘song’ of two massive objects, way out in the cosmos, orbiting into collision.

  As usual with the management of ‘big science’ projects, targets and time-lines had been set. As planed, after nearly 5 years of refit, a 3 - 10 times more sensitive aLIGO would start its upgraded run "O1" on 18th September 2015; to end again for upgrade on 12th January 2016. Run "O2" planned to start on 30th November 2016; to end 25th August 2017. Of the many things that could be of interest about aLIGO here, just two are highlighted for this dialogue. Mergers and chirps.

  The first thing of interest here is the merger of two massive objects orbiting into collision. Targeting known astronomical phenomenon, the gravitational wave data sets that aLIGO was expected to have the best probability of finding was that for the merger of two closely rotating massive objects. In this case, the merger of two (binary) neutron stars. Although thousands of other gravitational wave inducing phenomenon have been investigated by the LIGO consortium, including the merger of binary black holes; binary neutron stars, because they were already identified by other and optical methods; the probability of these events were better known; at around 1 or 2 events a year; for the volume of space that aLIGO could at its limits be able to detect. So the merger of binary neutron stars were the objects that the now Advanced LIGO was first expected to find.

  The second thing of interest here is about ‘chirps’. After all the high mathematics of astrophysics and relativity are as best considered for the merger of two massive astrophysical objects. It turns out that because of the relatively small size dimensions (10-150 km dia) of these incredibly massive objects, that the orbits they describe just before they touch, are incredibly small and tight. Typically in the order of a ~=>300km diameter circle. So to maintain orbit, their orbital speeds are very high. The last few moments of rotation before they crash together to fuse into one resultant object, can generally roughly be described in three stages as; the inspiral, the crash (merger) and the ringdown. The inspiral, because of their size and mass, is limited to be a rotation between around 100-200 revolutions per second. Because of their incredible masses (2-100 MSol), their gravitation ripples space-time, thus putting energy into space-time and loosing rotational kinetic energy, and thus causing them to get closer together. All of which rotation, constrained by the laws of physics for gravitationally bound masses in close orbit, to balance the required maths, means that they are moving at a velocity measured in fractions of the speed of light. When they touch and crash together, they exchange body fluids to become one entity. The event needs to reorganise all their intrinsic spin and kinetic rotational energy into one body, and for that system at that time, causing a maximal gravitational disturbance of space-time. The transfer converts some of their matter into gravitational wave energy in the process. So the received gravitational wave signal oscillates to a peak; generating a waveform of rising amplitude that raises in frequency from ~ 10Hz up to ~ 100Hz or so. The resultant entities mass then goes into ringdown; much like the ring of a bell, as the glob of matter reorganises itself into a sphere, under the influence of the extreme gravitational forces that its new mass dictates. The ringdown is a higher frequency event, though less gravitationally severe than the merger; and is estimated to be in the vibrational kHz range. So that’s the gravitational wave merger signal that, if found, can fortuitously be converted into the song of an audio ‘chirp’; as the signals lie within our audio frequency band.

  Finally, the significance of the ‘All-Sky’ aspect of gravitational wave (GW) detection cannot be overstated. Event networking alerts with observatories seeing in other domains like neutrinos, gamma sources and the more line-of-sight instruments in the conventional electromagnetic (EM) spectrum, is an important facet of collaborative science. And it works in both directions, for significance of event confirmations. So it can be asked, which of these events and mergers detectable by GW methods could be observable with other telescopes?

  Mergers of binary black holes (BBH’s) are not likely to be seen as there is no matter as we know it, to be gravitationally distorted; as emissions are contained within the event horizons; but we may yet have some surprises here. In that, are BH mergers always ‘perfect’? Around these conditions of highly distorted space-time, are there any turbulent points where the conditions of singularity brake down, and the merger leaks matter? On the other hand, as others have commented, if either or both black holes have a band of accretion material (matter) around them; the matter could generate gamma, x-ray, UV radiation as some of it is tidally squeezed when falling into the new larger black hole. On the other hand, grand firework displays, across the entire EM spectrum are expected for; black hole & neutron star and binary neutron star (BNS) mergers, (with or without accretion disks) as these mergers involve conventional matter. BNS mergers are currently postulated to generate gamma-ray bursts. Somewhere in there, neutrino events are also likely; particularly around any NS mergers; or events around any large novae. Like the creation of new NS’s and BH’s that ultimately will be GW detected.

UpDate: tobagojo - San Fernando, Trinidad, TT. 21st October 2017.

LIGO_Caltech Media_Kathy Svitil_ref-beckett_H1_HiResHanford_3B_r5.65-NR-shp_1366w_768h
  LIGO - Advanced Laser Interferometer Gravitational Wave Observatory - H1 (Hanford)
  US National Science Foundations Advanced Laser Interferometer Gravitational Wave Observatory, Hanford, Washington, USA - 4 km arms. LIGO uses a Dual Recycled, Fabry-Perot Michelson Interferometer (DRFPMI) developed collaboratively at GEO600.
  Caltech Media, Kathy Svitil, Ref: beckett

  And GO

  As would be expected, procedural preparations were well underway at the two LIGO facilities in the shakedown before the start of the much publicized Advanced LIGO observing run "O1"; to start on 18th September 2015; and to end 12th January 2016. Just around 2 weeks before the run "O1", aLIGO L1 at Livingston, Louisiana, and 3,030 kilometres (1,883 miles) away at aLIGO H1 at Hanford, Washington; both observatories were coming on-line, running system checks. By about a week before "O1" they were both fully functional and stabilised, and still running system checks. Then they had an unexpected bit of luck.

  What later became famously known as the GW150914 event; on the 14th September 2017 (GPS time 1126259462, or at 09:50:45 UTC) aLIGO L1 at Livingston first registered a signal, followed 6.9 (+0.5 -0.4) ms later, by H1 at Hanford. Gravitational Wave Astronomy had seen and recorded its first event. Surprised, suspicious and super-cautious, LIGO L1 and H1 went into overdrive. Knowing, besides the excitement, that it would take time to solidly confirm what and the character of the event that they had detected; and as well be responsible to continue the "O1" run; the tight LIGO and VIRGO consortium went into lockdown silence on what they had found, until all the science had been properly checked, and continued into the "O1" run as normal.

  However, because LIGO/VERGO is essentially an ‘All-Sky’ survey tool, as part of a developing Advanced LIGO and VIRGO scientific collaboration operational GW ‘trigger’ protocol, a real-time network operates to alert selective established EM (Electro Magnetic) groups of astronomers to point their line-of-sight telescopes to observe for possible related transient gamma, X-ray, UV, optical or radio phenomenon. For the GW150914 event, as part of this exercise, the SWIFT orbiting high-energy observatory was queried within 48 hours, to look for gamma-ray bursts, but nothing positive resulted. A further developed of this GW ‘trigger’ protocol would lead to notable successes, some time later.

  As the aLIGO researchers are members of a keen scientific community, spread far over the globe, following their unusual change in behaviour after the GW150914 event information lockdown, suspicion arose from those colleagues outside the group that they were onto something, and something big. Within two weeks of the event, speculative leaks began to appear in the social media. And the speculation got very near to the truth when a ‘LIGO_mole’ (or imitation, who knows?) sleuthed onto the networks. Rather than being phased by such revelations and also to some rather brutal criticisms of their scientific methodology in between, the LIGO consortium management stoically stood their ground, advising members to hanker down, remain vigilant, get their reports done; and adopted a ‘lets get the job done properly’ attitude. Silence is a hard thing, both ways; particularly to probing sensation seekers. It all played off handsomely. The probes never got their hands on the hard confirmation data they were seeking.

  And now, all seemingly too soon, it was time to tell the world what aLIGO had found.

UpDate: tobagojo - San Fernando, Trinidad, TT. 22nd October 2017.

  Windows on Gravity

  Publicity day was the 11th February 2016 from the US Capitols National Press Club, 529 14th Street, NW, 13th Floor, Washington, DC 20045. All video linked to LIGO’s research principals at Caltech and MIT. The media conference was hosted by the National Science Foundation (NSF), one of aLIGO’s principal sponsors.

  The Director of the NSF, astrophysicist Dr. France Córdova, warmly opened with a welcome address to all, acknowledging the LIGO, VIRGO and GEO scientific collaboration, principal partners Caltech and MIT and the major international contributor groups, The Max Plank Society, the UK Science and Technology Facilities Council and the Australian Research Council. She then went on to comment that the NSF had taken a huge risk in supporting LIGO, its largest project commitment at the time, but nevertheless that was its function, to support science and to advance technologies and learning.
  A brief video-introduction to gravitational-waves was then presented.

  Dr. Córdova then moved to the head table to join Prof. Gabriela González, Spokesperson, LIGO Scientific Collaboration, Professor of Physics and Astronomy, Louisiana State University; Prof. Rainer Weiss, Professor of Physics Emeritus, MIT; and Prof. Kip S. Thorne, The Feynman Professor of Theoretical Physics, Caltech.

  Executive director at Caltech of the Advanced Laser Interferometer Gravitational-Wave Observatories (aLIGO), experimental laser physicist Prof. David Reitze, took to the podium and smilingly announced "Ladies and gentlemen, we have detected gravitational waves. We did it!" to which there was tumultuous applause. He then concluded his beginning, after the noisy pause, with a modest “I am so pleased, to be able to tell you that.”

  He then explained that what LIGO had detected was the merger of two Black Holes that had occurred about 1.3 billion years ago. He then went on to stress the enormity of the technological achievement by stating “LIGO is the most precise measuring device ever built.” While explaining the character of the received waveforms, he mooted one of the experiments achievements as “Exactly …what Einstein’s theory of relativity would predict for …two Black Holes …inspiralling …merging together.” Prof. Reitze remarked that it had taken months of careful analysis with the collected data to be assured that what was being announced today “…was a gravitational wave.” then calmly adjusted the events focus from the now “This is not just about Gravitational Waves; that’s the story today”, then pointed to the future, with “what’s really exciting is, what comes next?”
  Drawing a reference from the history of the sciences he explained “400 years ago, Galileo turned a telescope to the sky and opened the era of modern observational astronomy.” and continued with the conviction that “I think we are doing something [as] equally important today. We are opening a window on the universe, a window of gravitational astronomy.”
  A video of the inspiral of two black holes, demonstrating the gravitational waves produced, and how they are propagated through space-time to the LIGO detectors on Earth; was shown, with Prof. Reitze providing explanations.
  While beginning his closing statements Prof. Reitze reiterated the staggering precision of the LIGO interferometers by comparing their sensitivity to the distance of the nearest star to the sun, Alpha Centauri as “…to the width of a human hair at the distance of 4.4 light-years.” He commented on the audio promises of the experiment with “…we may hear things that we never expected,” and asserted the possibilities of this new gravitational astronomical window with “…we may see things that we never saw before.”
  Prof. Reitze concluded with a lauded 20th Century analogy “This was …a scientific moon shot. We did it. We landed on the moon!” and in behest to the LIGO scientific collaborations, thanked the NSF, the US Congress and the US tax payers, for supporting such a risky project.

  Next were presentations from the aLIGO team to deliver the gist of the science and some meaning to the projects discoveries.

  Spokesperson, LIGO Scientific Collaboration, astrophysicist Prof. Gabriela González started by emphasising that the effort for the discovery was an international effort “…a World wide village” with the LIGO collaboration and the VERGO collaboration from Europe, with over 1,000 international members. She then briefly described the LIGO detectors at the NSF’s Livingston (L1) and Hanford (H1) facilities; and noted that the planning specified two instruments, for comparison, to allow confidence in the verification of any received signals.
GW170104 received GW plots_191-gw_data_3-panel_by LIGO_1000w_Modified-BASE-02.jpg  With an enthusiastic “So, this is it! This is what we saw.” Prof. González displayed two waveforms of “Strain”, the magnitude of the gravitational distortion of space-time, verses “time”, the period over which the signal appeared; first received at L1, and then ~ 7 mille-seconds later by H1, in confirmation of the event. “This is it!” she explained “That’s how we know we have gravitational waves.”   “But we know a lot more than that” she went on to explain, indicating the diagrams of oscillating waveforms with a rise in amplitude, together with a rise in frequency to a peak, and then the drop off.
  “That’s exactly the predictions that we know from solving Einstein’s equations on computers, for the coalescence of two Black Holes; …into one.” She then graphed the predicted matching relativistic overlay onto the received signals diagrams, and then exclaimed “ …this is the fantastic news!”
  Presenting a new overlay diagram of the two received waveforms, time shifted to match both signals, Prof. González went on to explain “From these waveforms, you can tell a lot more.” From the frequencies within the signals, the masses of the initial black holes can be estimates as 29 and 36 Solar masses. From comparison with the relativity solutions, the resultant larger single black hole has a reduced total mass of 62 Solar masses. Where 3 Solar masses were converted to energy in the merger and emitted as gravitational waves; were Prof. González further explanations.
  “We can tell even more than that” Prof. González expressed, saying that from the amplitude of the waveforms, the time of the event could be deduced as “1.3 billion years ago; when multi-cellular life, here on Earth, was just beginning to spread.”
  Prof. González then alerted the audience to the fact that all the relevant scientific information about this gravitational wave discovery could be found in a paper on-line; published this day in Physical Review Letters (DOI: 10.1103/PhysRevLett.116.061102) - (See below). Other papers on related scientific and technical details were also now available on-line and from other sources.
  A coloured plot of the time vs frequency characteristics of the received gravitational waveforms was displayed by Prof. González, with the note that the amplitude gets brighter as time advances on the plot. She then emphasised the fact that these generated frequencies were within our auditory sensing range, the human hearing range.
GW170104 received GW plots_LIGO Chirp_by LIGO_Snapshot - 30_1920w_1080w.jpg   “We can hear gravitational waves, we can hear the universe. …That’s one of the beautiful things about this, we are not only going to see the universe, we are going to be listening to it.” she then looped a video interactive audio recording of a slowed down version of the gravitational waveform for the audience to observe and hear “…do you hear that? The rumbling noise, then the chirp?” asked Prof. González, replaying the display with a restrained show of obvious excitement, then exclaimed “That’s the chirp we’ve been looking for!. This is the signal we have measured.”
  “We can even tell more. Because we have two detectors, it’s like having two ears.” Prof. González drawing from the ‘All-Sky’ aspect of these GW telescopes, then displayed an image of the southern sky, with a graded probability plot of location overlaid onto the Magellanic cloud region of the MY galaxy. “Not very good” she conceded, “but this will get better” over time as the network of more GW telescopes came on-line. She then displayed a world map with the location of operating, under-construction and planned GW telescopes to explain. The two LIGO instruments at Livingston and Hanford, and the technology demonstrator GEO600 in Germany, were now functioning. VIRGO in Italy was expected to come on-line later this year, in mid 2016, “ we will have three ears” she explained. The underground Japanese detector KAGRA (formerly the Large-scale Cryogenic Gravitational wave Telescope, LCGT) now under-construction, should be on-line some time in 2018. A LIGO India project awaited approval.

  Wrapping up her presentation, Prof. González stated “This is just a beginning, We discovered gravitational waves. …from the merger of black holes. It’s been a very long road, but this is just the beginning. This is the first of many (discoveries) to come” she predicted. With the present detectors and as more GW telescopes become operational, she beamed with gleeful enthusiasm “…we begin listening to the universe!” she concluded.

  co-Founder LIGO, experimental astrophysicist Prof. Rainer Weiss began his explanations from a historical perspective, with the reminder that, recently celebrated in Centenary, Einstein had first formulated the field equations for gravity in 1915. They was a complete departure from previous understandings about ‘forces’, to instead consider ‘distortions’ in space-time. An un-scaled diagram representing the 2D ‘distortion’ in space-time by the masses of the sun and earth was shown. In 1916 Einstein applied the field equations to finding a way for these ‘distortions’ to communicate the dynamics of movement, for which he described as gravitational waves, propagated in space-time at the speed of light. He elucidated that gravitational waves were ‘strains’ in space.
  Prof. Weiss then demonstrated changes in space ‘strain’, by stretching a piece of green plastic netting, illustrating that it was this change in ‘shape’, as each node in the distorted netting showed, that represented the ‘strain’ change in space; that the LIGO instruments were attempting to measure. Prof. Weiss then alluded to the fact that whereas Einstein was a good experimenter; 100 years ago, astronomers had not as yet discovered massive objects compact enough, nor was the technology available advanced enough, for any experimental test that Einstein may have envisaged or designed, to have been workable. Einstein thus remained doubtful that gravitational waves were at all detectable. Prof. Weiss stressed that it has been the discovery and development over the past 100 years, of such things as black holes, neutron stars, and advanced technologies; that has allowed us these new discoveries.
  Prof. Weiss then went on to express some idea of the finesse of the LIGO instrumentation. The enormously tiny measurements they make. He expressed this with “Start with (the measure of) a meter. Divide it by a million, three times over. …that’s a thousandth the size of a nucleus.” and if that wasn’t enough of a head bender “So how do we do it?” he challenged. “We do it by timing light” he offered. He then went on to show an animation of the basic principles of a working Michelson interferometer; a principal component of LIGO; an instrument attuned to measure changes in the wavelength of monochromatic (Laser) light.
  Prof. Weiss went on to explain that there were a lot of things necessary to make to reduce noise sources in the instruments, one of which was vibration from the earth. He then demonstrated with a hand-held pendulum, that represented the interferometers mirrors, how controlled lateral high frequency movements of its supporting structures could remove one aspect of the perturbating noise sources. A diagram of the mirrors actual suspension system was shown as example (However its intricate functions were not here explained any further).
  Prof. Weiss continued by describing that there were very many other noise sources, as examples thermal and quantum noise, which had to be overcome. He then speculated that had all of this technology been available to Einstein in 1916, that Einstein himself would probably have designed LIGO. He qualified this by stating that Einstein was smart enough to do it, and then with witty conviction, threw a wry carrot at his good colleague Thorne with “He (Einstein) wasn’t just a theorist!” which brought a peal of laughter from the high table.
  In a masterful move to quench his jest, he turned the attentions onto Prof. Thorne by relating a story (Home) taken from the book Black Holes & Time Warps - Einstein’s Outrageous Legacy, written by Thorne, in which intrepid explorers visit the event of the merger of a pair of 24 Solar-mass black holes. Taking up the story at the moment of the black hole merger, Prof. Weiss in good animation recalls “…and the universe gives a little burst, when that is over.” pausing, then “That’s all in that book, written in 19(9)3.” he states, pointing a finger at Thorne. Then dramatically declares “And we actually have seen it!”

  Prof. Weiss then called Prof. Thorne to his turn at the podium, with a warm gesture and the words “So, Kip.”

GW170104 received GW plots_Warped Spacetime BBH Simulation_by Simulating eXtreme Spacetimes (SXS) Project-LIGO_Snapshot - 31_1920w_1080w.jpg GW170104 received GW plots_Warped Spacetime BBH Simulation_by Simulating eXtreme Spacetimes (SXS) Project-LIGO_Snapshot - 32_1920w_1080w.jpg

Real 3D ==> 2D space-time surface membrane simulation.
Relativistic Binary Black Hole merger computer simulation. Count-down time == before (rising chirp), to merger [freeze], and after (Ringdown).
By Simulating eXtreme Spacetimes (SXS) Project - LIGO

Colors depict the rate at which time flows; arrows in the normal direction of time.
In the green regions outside the holes, time flows at its normal rate. In the yellow regions, it is slowed by 20 or 30 percent.
In the red regions, time is hugely slowed. Far from the holes, the blue and purple bands depict outgoing gravitational waves.
Below picture is a chirp waveform that gets progressively covered in blue over time.

GW170104 received GW plots_Warped Spacetime BBH Simulation_by Simulating eXtreme Spacetimes (SXS) Project-LIGO_Snapshot - 33_1920w_1080w.jpg GW170104 received GW plots_Warped Spacetime BBH Simulation_by Simulating eXtreme Spacetimes (SXS) Project-LIGO_Snapshot - 34_1920w_1080w.jpg

  co-Founder LIGO, theoretical relativist Prof. Kip S. Thorne began his segment with the reminder that Prof. Weiss has been a principal designer of the LIGO laser systems together with the absent co-Founder LIGO, Scottish experimental physicist, laser stabilisation, Prof. Ronald Drever, post Professor of Physics Emeritus, Caltech, who had sent well wishes to all, but regretted to be presently medically indisposed.
  Prof. Thorne continued with a brief history of LIGO, citing past pioneer Joseph Weber (1919 - 2000) at the University of Maryland; and later laser research conducted at Caltech, MIT and in Scotland and Germany, as crucial contributions. He noted that the LIGO, who’s results are displayed today, was upgraded to Advanced LIGO roughly between 2010 and 2015; and provided these spectacular results almost as soon as the improved instruments started. He then demonstrated a 2D relativistic computer simulation of a binary black hole (BBH) merger, illustrating the resulting distortions to space-time; and how they matched the signals received at aLIGO.
  Prof. Thorne then speculated on other gravitational phenomenon that aLIGO could possibly detect; spinning neutron stars, BH and neutron star mergers, binary neutron star mergers, supernovae events and cosmic-string signatures from the early inflationary expansion period, just after the birth of the cosmos.
  Prof. Thorne continued his speculations in comparing progressive discoveries made by astronomers as they moved through the spectrum provided by optical, radio and x-ray telescopes, in suggesting to expect “bigger surprises” from the new gravitational wave window. He concluded that gravitational wave telescopes would, in the future, improve their time domain sensitivity from mille-seconds to include, minutes, hours, days, years, decades and finally even billions of years; “its really remarkable that LIGO is such a fantastic beginning.”

  He then turned to Dr. Córdova, and on behalf of the LIGO collaboration, thanked the NSF, Dr. Córdova and her predecessors, for providing “A fabulous 40 year partnership” and ended his discourse with “…a great triumph. A whole new way to observe the universe.”

  Dr. Córdova, Director of the NSF, returned to the podium to round off proceedings before question time by the media.
  “Einstein would be beaming, wouldn’t he.” she started with a smile. Unabashedly moved by the historic significance of the proceedings, in which her student field of interest had been an early investment in what had been at the time, only dreamy speculation; to have had a hug from “…a faculty mentor …when a grad student at Caltech” set her to reminisce that both Kip Thorne and past pioneer Joseph Weber (whose wife she courteously acknowledged as present in the gathering) had filled her student head with imaginings by stories of black holes. “And look where we’ve come now!” she nodded “Amazing!”
  Transforming herself back again into a functionary of the NSF; addressing the full membership of the LIGO collaboration, she noted “Mark this day as truly historic. I commend each of you.” She moved on to commend past programme directors of the NSF for their steadfast support for the LIGO project, over the past 40 years; and called for a show of gratitude. To which there was strong applause in reply.
  Dr. Córdova then delivered an impassioned summary of the entire project.
  She acknowledged astronomer, astrophysicist and historian science and astronomy Dr. Virginia Trimble, as an invited guest, in witness to her late husband Joseph Weber’s pioneering influences on the LIGO project; and noted that some of his instruments are now housed at the NSF LIGO facility at Hanford, Washington.
  Dr. Córdova continued her summary speckled with words like, visionary, drive, persistence, commitment. She noted that this was not a single persons achievement, but that of many, and that its success achieved only through collaboration. That this applied as well at a national level, where the support with funding and scientific expertise, by other national participants, was a significant and necessary component. She then called on the invited respective representatives of the supportative national Science Councils of Germany, the UK and Australia, to please stand and be accounted. To which again, there was strong applause. She reminded everyone that all these national participants had all contributed directly to Advanced LIGO’s success; and reminded the media to consult them as well, to get a full perspective of the discoveries presented.

  Dr. Córdova then turned proceedings over to questions by the media.

The NSF LIGO 11th Feb 2016 anouncement at the National Press Club, Washington, DC, USA.

Gravitational Waves Detected 100 Years After Einstein's Prediction - Caltech Media Assets: HERE
All relevant videos to GW Discovery + About LIGO

UpDate: tobagojo - San Fernando, Trinidad, TT. 22nd October 2017.

The Song in Space-Time
GW150914: Observation of Gravitational Waves from a Binary Black Hole Merger

 Observation of Gravitational Waves from a Binary Black Hole Merger

 Physical Review Letters PRL 116, 061102 (2016) 
B. P. Abbott et al.*
(LIGO Scientific Collaboration and Virgo Collaboration)
(Received 21 January 2016; published 11 February 2016)

  On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0 × 10-21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1s. The source lies at a luminosity distance of 410+160-180 Mpc corresponding to a redshift z = 0.09+0.03-0.04. In the source frame, the initial black hole masses are 36+5-4 Msol and 29+4-4 Msol, and the final black hole mass is 62+4-4 Msol, with 3.0+0.5-0.5 Msol*c2 radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

* Contributors listed in source

Factsheet_GW150914_1st gravitational wave detection_20150914-09-50-45-UTC_LIGO L1 H1_01_635W_875h

  GW150914: Observation of Gravitational Waves from a Binary Black Hole Merger factsheet.
The LIGO Observatories, L1 + H1, USA, historic 1st gravitational wave detection called GW150914; 14th September 2015 @ 09:50:45 UTC.
The LIGO Scientific Collaboration and VIRGO Collaboration; A collaboration for this 1st effort of 133 internationally significant Scientific Institutions; with over 1,004 noted individual members from 15 contributing nations, of all disciplines listed, including posthumous citations.
  Phys. Rev. Lett. 116, 061102 – Published 11 February 2016; Abstract, PDF.

  This was certainly some event, and as stated; the first detection of gravitational-waves and the first detection of a binary black hole merger. It was also the first time that gravitational waves were used as a tool for observational astronomy. It also provided another direct confirmation of Einstein’s field equations of General Relativity, roughly 2 months short of 100 years after they were first proposed on 25th November 1915.
  Without further unnecessary superlatives; this was a commendable and historic achievement.

  A few things of note in retrospect to the detection event; is that the expected binary neutron star merger was not the first event detected as was first anticipated. As there is no previous history of BBH mergers recorded on which to base a prediction on the likelihood that a merger would be found, the chance of finding a BBH merger however was more surprising than unexpected. Another thing is that as neutron stars are less massive than black holes, and BBH mergers generate larger GW signals than BNS mergers, BBH mergers are easier to detect. A more sensitive instrument would help to find the BNS mergers. But all of this is sort of speculative; as the abundance of BBH and BNS mergers in the near and far field is not yet well enough known to tell. But these new GW instruments are sure to put a finger on the problem.

  An interesting aspect of the LIGO/VERGO collaboration is their attitude as to how they publish their critical research documentation. It has long been speculated that if LIGO ever did get to detect gravitational waves, that because of the noted significance of such an achievement, some person(s) associated with the project would likely be nominated for a Nobel prize. However, prior to the LIGO GW discovery in 2015, declared in 2016; back around 2014, the scientific community were voicing some disquiet about the narrowness of only a few people being acknowledged with a Nobel, and sometimes some significant person had been left out, and certainly no ‘team’ group as a whole had ever been acknowledged with a Nobel. While the general arguments may not be without merit, and where the-few-who-were-left-out syndrome could be moderated to correction by a Nobel committee applying a bit more diligence; the real facts of the matter are a little more stark. The Nobel committee are only following the wishes and letter of the last will and testament left by Alfred Nobel when he bequeathed the Nobel Foundation. Each prize is limited to 3 recipients in any one category or to 4 or 5 at most, if one can cleverly reason a legal split of category; but certainly no more. It’s as simple as that. Oh, and also by writ, no posthumous Nobel’s are awarded; unless the recipient has unfortunately died after being officially publicly awarded.
  In a sort of oblique application of the currently in vogue euphemism of push-back; the ‘big science’ project community, moderately aware of the limitations of the Nobel committee, have come to be very diligent when preparing their papers for publication. In ever hopeful but mild protest for a group prize, they carefully list all who have contributed to their projects. To be sure, it was not always so, but the community has certainly become more responsible recently in this regard. As to whether the trend is driven by wistful Nobel push-pack or by sheer better practice, which has other benefits; is debatable.

  Notably, the LIGO/VERGO collaboration were astutely vigilant in this regard, in that they carefully listed around 1,004 significant member contributors to their first GW detection achievement; and also diligently cited posthumous members. Whether this may be a record in itself or not, is probably not that significant; but what is, is that it represents peer acknowledgement of valid team effort and puts a high value to its human resources.
  This has the unusual benefit of a win-win for all. If they succeed, which they have, they all win. If any one of them alone is specially acknowledged, then implicitly they are all acknowledged and they all win again. Isn’t that cute! (see later)

VIRGO, Pisa, Italy_Virgo-Polgraw, br-NR-shp_1020w_320h
  VIRGO - European Advanced Laser Interferometer Gravitational Wave Observatory, Pisa, Italy - 3 km arms
  Virgo-Polgraw team,, Poland
  CNRS (France), INFN (Italy), NIKHEF (Netherlands), POGRAW (Poland), RMKI (Hungary)

  Official List of Gravitational Wave Detections - 12 September 2015 to 23 October 2017


Event code


Date Detect

Time UTC

Date Pub



Science Links



Merger BBH




Observation of Gravitational Waves from a Binary Black Hole Merger

The first observation of gravitational waves was made on 4 September 2015 at 09:50:45 UTC (GW150914, merger BBH) announced 11 February 2016. Observed by the L1 and H1 LIGO detectors in the USA, just before Advanced LIGO's first observing run "O1"; started on 18th September 2015; to end 12th January 2016.

Phys. Rev. Lett. 116, 061102 (2016) - Published 11 February 2016;
Abstract, PDF.



Merger BBH




Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

The second observation of gravitational waves was made on 26 December 2015 at 03:38:53 UTC (GW151226, merger BBH) dubbed "the Boxing Day event" and announced on 15 June 2016. Observed by the L1 and H1 LIGO detectors in the USA, near the end of Advanced LIGO's first observing run "O1"; started on 18th September 2015; to end 12th January 2016.

Phys. Rev. Lett. 116, 241103 (2016) - Published 15 June 2016;
Abstract, PDF.



Merger BBH




Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

A third observation of gravitational waves was made on 4 January 2017 10:11:58.6 UTC (GW170104, merger BBH) and announced on the 1 June 2017. Observed by the L1 and H1 LIGO detectors in the USA. During Advanced LIGO's second observing run "O2"; started on 30 November 2016; to end 25th August 2017.

Phys. Rev. Lett. 118, 221101 (2017) - Published 1 June 2017;
Abstract, PDF.

The European Advanced VERGO detector comes on-line in Pisa, Italy, 1st August 2017



Merger BBH




A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

A fourth observation of gravitational waves was made on 14 August 2017 10:30:43 UTC (GW170814, merger BBH) and announced on the 22 September 2017; but significantly observed by the L1 and H1 LIGO detectors in the USA and also for the first time by the European Advanced VERGO detector that had come on-line in Pisa, Italy on 1st August 2017. Significantly, with 3 detectors now on-line, much tighter spatial coordinates of the observed BBH merger could be given and additional science on gravitational wave polarisation was newly explored. During Advanced LIGO's second observing run "O2"; started on 30 November 2016; to end 25th August 2017.

Phys. Rev. Lett. 119, 141101 (2017) - Published 6 October 2017;
Abstract, PDF.

On 3rd October, the 2017 Nobel Prize for Physics is awarded:
'For decisive contributions to the LIGO detector and the observation of gravitational waves'



Merger BNS




Observation of Gravitational Waves from a Binary Neutron Star Inspiral

A fifth observation of gravitational waves was made on 17 August 2017 at 12:41:04 UTC (GW170817, merger BNS) announced on the 16 October 2017; observed by the L1 and H1 LIGO detectors in the USA and by the European Advanced VERGO gravitational-wave detectors made their first observation of a binary neutron star inspiral. During Advanced LIGO's second observing run "O2"; started on 30 November 2016; and just before the end of the run scheduled 25th August 2017, for system updates.
The association with the γ-ray burst GRB 170817A, detected by Fermi-Gamma-Ray Burst Monitor (GBM) 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

Phys. Rev. Lett. 119, 161101 (2017) - Published 16 October 2017;
Abstract, PDF.


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Science Links

  The 2017 Nobel Prize for Physics

  The 2017 Nobel Prize for Physics was announced on the 3rd October 2017. The announcement stated:

  ‘For decisive contributions to the LIGO detector and the observation of gravitational waves’

    The recipients were:
  1. Barry C. Barish, Ronald and Maxine Linde Professor of Physics, Emeritus, Caltech; Principal Investigator of LIGO, 1994-97; Director, LIGO, 1997-2006.

  2. Kip Thorne, theoretical relativist, Richard P. Feynman Professor of Theoretical Physics, Emeritus, Caltech. co-Founder LIGO.

  3. Rainer Weiss, experimental astrophysicist, Professor of Physics, Emeritus, MIT. co-Founder LIGO.

  4. Barish & Thorne shared award of ½ the prize
    Weiss awarded ½ the prize

  It is speculated that, had the Nobel prize for Physics been given for LIGO/Gravitational Waves in the earlier period 2015/2016, instead of in 2017; Ronald William Prest Drever (26 October 1931 – 7 March 2017) Scottish experimental physicist, laser stabilisation, co-founded LIGO project, co-inventor of the Pound–Drever–Hall laser stabilisation system, Professor Physics, Emeritus, Caltech, would have been accounted to share in the Nobel prize.
Nobel’s are not offered posthumously.

UpDate: tobagojo - San Fernando, Trinidad, TT. 24st October 2017.

GEO600, Hannover, Germany_600m arms_gravitational wave laser interferometer_yt-maxresdefault_2
  GEO600 - German Advanced Laser Interferometer Gravitational Wave Observatory, Hannover, Germany - 600 m arms
Max-Planck-Institut für Gravitationsphysik and the Leibniz Universität Hannover.
  YouTube - Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)

  GEO600 is a German-Anglo research and development project, a test bed for developing advanced laser technologies for use with gravitational-wave detection instruments which are called Dual Recycled, Fabry-Perot Michelson Interferometers (DRFPMI). GEO600 scientists are part of the international team which comprises the LIGO Scientific Collaboration (LSC).

  Under the jurisdiction of the Max Planck Institut für Gravitationsphysik (Albert-Einstein-Institut) and the Leibniz Universität Hannover, with partners in the United Kingdom; it is funded by the German Max Planck Society and the UK Science and Technology Facilities Council (STFC). Technologies developed by GEO600 scientists, together with a team at the Laser Zentrum Hannover (LZH), supplied the laser equipment for Advanced LIGO.

  The GEO600 provided advances in laser stabilization, absorption-free optics, relevant control engineering to provide vibration damping, and improved techniques for data acquisition and processing. They developed techniques for the amplification of laser light and signal called "dual recycling" and by using newly highly reflecting mirrors, constructively superposing the laser beam flow with itself, to enhanced the beam intensity in a process called "power recycling". For tuning control of frequency stabilisation they used an additional mirror to superpose the signal with itself, to provide a process call "signal recycling" in the control loop. In order to improve sensitivity of the system they developed a technique called "squeezed" laser transmission.

  GEO600 developed improved vibrational damping with mirrors suspended from glass fibres.

Gravitational-Wave Observatories Across the Globe_189-gw_global_detector_map_post VIRGO_by LIGO_1000w_529h
  Gravitational-Wave Observatories Across the Globe @ 2017
LIGO H1 (Hanford), L1 (Livingston); GEO600 (Germany); VERGO (Italy); KAGRA (Under Mount Ikeno, Kamioka mine, Kamioka cho, Japan); LIGO India (India).
  By LIGO Scientific Collaboration

   END - The Song in Space Time :: Extracted from posting The Professors Faulty Gravity - A Rejoinder by
KAGRA (LCGT)_DSC-CR0616_09_University of Tokyo Institute for Cosmic Ray Research_900w_596h
  KAGRA - (Kamioka Gravitational Wave Detector) Gravitational wave Observatory, 200m under Mount Ikeno, Kamioka mine, Kamioka cho, Japan. 3km arms.
The KAGRA project was formerly the Large-scale Cryogenic Gravitational wave Telescope (LCGT) before 2012.
  By the University of Tokyo, Institute for Cosmic Ray Research ICRR)

  TAMA300, was a prototype 300m power recycling, Fabry-Perot Michelson Interferometer (FPMI), the first Japanese Laser Interferometer Gravitational Wave Antenna, a project of the The Gravitation Wave Project Office of the National Astronomical Observatory of Japan (NAOJ), located at the Mitaka campus, Tokyo, Japan. The project was started in 1995 and studied low-loss optical materials initially tested at room temperatures. It became an operational facility, with data collection, between 1999 to 2004. The project was decomissioned in 2005, and its research handed over to the Physics department, Institute for Cosmic Ray Research (ICRR, 1976) at the University of Tokyo.

KAGRA GW Observatory, 200m under Mount Ikeno, Japan_DSC-CR0616_04_University of Tokyo Institute for Cosmic Ray Research_set-02_900w_620h

  The ICRR in planning for a Large-scale Cryogenic Gravitational wave Telescope (LCGT), because of the general seismicity around Japan, decided to put all LCGT interferometer instruments underground to minimise surface-wave seismic interference. The Kamioka mine, Kamioka cho, was chosen as the site.

  Operated in the Kamioka mine between 2005 and 2007, as a follow on from the TAMA300 project, was a proving platform for the LCGT technologies called the prototype Cryogenic Interferometric Observatory (CLIO) detector. CLIO, an orthogonal 100m interferometer investigated and developed cryogenic cooling and suspension systems with sapphire mirrors for the laser, successfully reducing some aspects of thermal noise in the system. The system was run by the Physics department, Institute for Cosmic Ray Research at the University of Tokyo. CLIO completed fundamental technology developments by 2012.

  The LCGT began its first phase of construction, 200m under Mount Ikeno, Kamioka mine, Kamioka cho, Japan in 2010, the works were expanded later to build the new 3km (1.9 mi) orthogonal tunnels.

  Around that time the LCGT saw a name change. The LCGT morphed to be called the Kamioka Gravitational Wave Detector as the tunnel construction proceeded. The name KAGRA comes from a combined play on two english words. 'KA' from the name of the deep underground Kamioka mine, in which the project was to be built; and 'GRA' from the word gravity, of which gravitational-waves are the projects detection objectives. The term 'KAGRA' came to general use, then to official acceptance, at around the time the new 3km expansion-build was begun in 2012. The excavation phase of tunnels was completed on 31 March 2014.

  The development of GW detectors in Japan has not been as smooth a process as at first hoped. Funding and technological challenges being perhaps the main cause. Some of these challanges may now have been mitigated as KAGRA is now a member of the LIGO/VIRGO Scientific collaboration, and thus privy to new technological innovations that this collaboration offers. More lately in 2014-15, delays have been caused by unanticipated water seepage into the new tunnels being excavated.

  Phase 1 of the KAGRA, a power recycling, Fabry-Perot Michelson Interferometer was completed and tested in 2016. Phase 2, with upgraded cryogenic mirror systems, lasers and other systems is targeted to be on-line some time in 2018. KAGRA is operated by the ICRR through the University of Tokyo; and is supported by the Gravitation Wave Project Office of National Astronomical Observatory of Japan (NAOJ), Mitaka campus, Tokyo, and the High Energy Accelerator Research Organization (Ko Enerugi Kasokuki Kenkyu Kiko; KEK, 1997) particle physics laboratory, Tsukuba, Ibaraki; Japan.

The incomparable Galaxies & Galactic Clusters

NGC4458 an eliptical galaxy of the Virgo Cluster_HST-2008_hs-2008-30-c_990w
10 - NGC 4458 a round eliptical galaxy of the Virgo Cluster
HST 2008 - NASA, ESA, E Peng (Peking University - Beijing)

NGC4660 an eliptical galaxy of the Virgo Cluster_HST-2008_hs-2008-30-b_990w
10 - NGC 4660 an ovoid eliptical galaxy of the Virgo Cluster
HST 2008 - NASA, ESA, E Peng (Peking University - Beijing)

ESO243-49_Spiral Galaxy Edge-on_HST_NASA,ESA,S-Farrell(Sydney-Institute-for-Astronomy,Uni-of-Sydney)_hs-2012-11-b-full_990w
10 - ESO 243-49 - A Spiral Galaxy viewed edge-on
HST 2012 - NASA, ESA, S. Farrell (Sydney Institute for Astronomy, University of Sydney)

10 - NGC 1300 a barred spiral galaxy
HST 2005

M104 - The Sombrero Galaxy spiral edge-on dark band of interstellar gas & dust + large central bulge marks it a ty-Sa even though its spiral arms cannot be seen_990w
10 - M104 (NGC 4594)- The Sombrero Galaxy with a dark band of interstellar gas & dust, the shape of which evokes its name.
It is classified a type Sa spiral galaxy.
HST, 6 image composite, 3 filters (R, G, B), May-June 2003; STScI-2003-28; NASA, The Hubble Heritage Team (STScI/AURA)
[Another beautifully informative version of this galaxy exists, by ESO, with specific infra-red filters discriminating bulge-stars from the halo-stars; awaiting copy (Ah! See below)]

  M104 is about 15kpc (50,000 lt-yrs) across and at a distance of some 31.13 Mpc (101Meg5 lt-yrs)(2016) [updated from 28Meg lt-yrs, 2003].
  The HST captures some 2,000 bright globular clusters within the body of the halo, 10 times more numerous than in our own MW galaxy, according to the NASA team.
  X-ray emissions from the core, measured with other telescopes, suggest that there is a Mega-Sol sized black hole residing in it.

10 - M104 (NGC 4594) - A stunning image by the ESO team. The Sombrero spiral galaxy seen edge-on.
ESO, 3 image composite, FORS1 instrument at VLT ANTU, 30 Jan 2000, eso0007a; V-band (central wavelength 554 nm; 112 nm Full Width Half Maximum 120 sec; blue), R-band (657 nm; 150 nm FWHM; 120 sec; green) + I-band (768 nm; 138 nm FWHM, 240 sec; red). ESO/P. Barthel; Mark Neeser (Kapteyn Institute, Groningen), Richard Hook (ST/ECF, Garching, Germany).

  In this ESO image, better seen as a bright ball in the centre (about a third of the galaxy in extent), is the large central bulge that marks it as a type Sa spiral galaxy, even though its spiral arms cannot be seen. Extended around the central bulge, and over the full width of the galaxies duty band, and beyond, are the 'dust' of stars termed 'the galectic halo' (A term applicable to any galaxy).
M104, Sombrero, HST + Subaru, 5 Feb 2015, NASA, ESO, NAOJ, Giovanni Paglioli, Proc R Colombari_m104colombari_q100_watermark_B_1920w_1080h
10 - M104 (NGC 4594) - The Sombrero Galaxy.
An updated mix of images from the HST and the 8.2-meter (320 in) Subaru telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii.
M104, Sombrero, HST + Subaru, 5 Feb 2015; NASA, ESO , NAOJ, Giovanni Paglioli; Processed by R Colombari.
Note: For some reason, the above image had to be ‘mirrored’ horizontally to correctly match the orientation of above 2 images; so it has an inverse orientation to the available HST + Subaru image.

  What a glorious image. Space and ground-based data have been reprocessed with simple colours to reveal a more natural hue; and presents details otherwise lost in the overwhelming glare of the galaxy.
  The intensity of the stars at the core and the form of the primary bulge are better seen. More detail of the dusty internal spiral arms is also apparent.
10 - M101 or NGC 5457 - The (Northern) Pinwheel Galaxy. A dusty spiral galaxy @ ~21 Meg Lt-Yrs (~6.4 Meg PC’s) distant, in the constellation Ursa Major. Diameter of around 170,000 lt-yrs (52,122 pc); Mass ~100 Giga M-Sol. The small bright central-bulge is estimated to contain ~3 Giga M-Sol.
Composite of 51 images; 3 telescopes:
HST team: K.D. Kuntz (GSFC), F. Bresolin (University of Hawaii), J. Trauger (JPL), J. Mould (NOAO), and Y.-H. Chu (University of Illinois, Urbana) Processing: Davide De Martin (ESA/Hubble)
CFHT image: Canada-France-Hawaii Telescope/J.-C. Cuillandre/Coelum
NOAO image: George Jacoby, Bruce Bohannan, Mark Hanna/NOAO/AURA/NSF
HST, CFHT & NOAO - NASA & ESA, 28 February 2006

  The original Pinwheel Galaxy (Pinwheel, or Catherine-wheel to the British) (resembling) a rotating firework, gained the prefix ‘Northern’ only after the study of its counterpart (M83) in the Southern skies (See Below).
  Historically attributed to Pierre Méchain as discoverer on 27th March 1781; who then communicated with Charles Messier on its discovery, who then verified its position for inclusion in his Messier Catalogue as one of its final entries, M101. William Herschel is noted to have observed it in 1784; and Lord Rosse with his 72-inch Newtonian reflector, ~1845+, who with the ability of his large-diameter instrument, was the first to observe its spiral structure, and made sketches for note in the record.
  Where dusty streaks of interstellar debris from older stars, with a high content of molecular hydrogen, vein and define the path of the spiral arms of the galaxy, young star-clusters predominate as bright spots within the arms. These young hot clusters are now irradiating the gas in their region to volumes of ionised H II. It is suggested that the new burst of star formation may have been promoted by the gravity induced density-waves in the spiral arms from M101’s more recent interactions with some of its neighbour galaxies, particularly NGC 5474. Five companion galaxies comprise the M101 group; NGC 5204, NGC 5474, NGC 5477, NGC 5585, and Holmberg IV. Some asymmetries in the M101 spiral appear to indicate a recent near collision; recent being in the order of a few 100 Meg years ago.
  M101 is estimated to be about 42% larger in diameter and 11% more massive, than the Milky Way Galaxy (120,000 lt-yrs; ~90 Gig M-Sol respectively).
M101_NGC5457_Visible_(Unk)_Anttlers101_rt+96_b_372px M101_NGC5457_Composit_infrared,visible,ultraviolet-and-X-rays_NASA_21st_Century_M101_b_372px
10 - M101 - NGC 5457 - Low resolution. (For comparison)
8" telescope with Canon 350D; Visible, From Kalkaska Mi, April 2007, by Anttler
10 - M101 - NGC 5457 - Low resolution. (For comparison)
Composite: Spitzer-ST, Infra-Red=Red (H & Dust); HST, Vis=Yellow-White (Old & Bright stars); The Galaxy Evolution Explorer (GALEX), Ultra-Violet=Blue (Hot young stars); Chandra, X-ray=Purple (Ultra energetic areas)
NASA, ESA, CXC, JPL, Caltech and STScI; 23 May 2012
10 - M83 barred spiral galaxy - The Southern Pinwheel
Spitzer ST infra-red (processed),Ir-(3.6 microns in blue)(4.5 microns in green)(8 micron in red), some 8 micron subtracted; NASA, JPL-Caltech

  A close barred spiral @ 15 Meg light-years distant. Very similar to the MW galaxy, although about half the size. M83 is called The Southern Pinwheel to distinguish it from a similar Northern Pinwheel, M101 (See Above).
  Colour enhanced for dust, this Spitzer image brings out the dusty arms of M83 in deep red. The galaxy also shows a extensive halo of stars that whitens the image.
NGC4414_A spiral galaxy-@60Meg-ly_100Gig-stars_Diamater-100,000-ly_Similar to the Milky Way galaxy_HST-NASA_990w
10 - NGC 4414 A spiral galaxy @ 60 Meg-ly distant with 100 Giga stars showing a diameter of 100,000 lt-yr
Similar to the Milky Way galaxy

M51 - The Whirlpool, a spiral galaxy of type Sb - Two galaxies merging_(sRGB) (probably HST)_990w
M51-Whirlpool Galaxy - Sketch by Lord Rosse (William Parsons) in 184510 - M51a - NGC 5194, The Whirlpool, a spiral galaxy and its companion NGC 5195 (M51b) in the constellation Canes Venatici.
Two galaxies merging.
HST ACS instruments (sRGB) The Hubble Heritage Project January 2005

  M51 (right) - Whirlpool Galaxy - Sketch by Lord Rosse (William Parsons) in 1845

  M51a a Type SA(s)bc spiral galaxy @23 ± 4Meg light years distant; approximate diameter of 43k light-years and mass estimated to be 160 Giga solar masses. These interacting galaxies will eventually merge together in Geiger years time. The companion NGC 5195 moves behind M51a on its orbital spiral which is estimated to have crossed into M51a some 50 to 100 Meg years ago; where computer simulations estimate that it previously crossed from behind some 500 Meg years ago.
  Bright blue clusters of stars occupy lanes behind the gravitationally induced density waves that circle the galaxy, promoting the spiral structure, where the peak of these waves now induces new star formation in the compressed regions of gas and dust in the more apparent pink and dark regions of the galaxy.
M51 - The Whirlpool, a spiral galaxy of type Sb, viewing details of the small merging component_(sRGB) (probably HST)
10 - M51a - NGC 5194, The Whirlpool, a spiral galaxy and its companion NGC5195 (M51b) in the constellation Canes Venatici. Viewing details of the small merging component.
HST using ACS instruments (sRGB) The Hubble Heritage Project January 2005

  Looking at the tip of a spiral arm of M51 that swirls over NGC 519 behind. Highlighted by the glow of creamy white ‘Stars like Dust’ of NGC 5195; recent (white) and emerging (pink) star clusters (not stars - individual stars are not resolvable at this distance with this instrument) on M51a are viewed in close detail of a complex three dimensional swirl of materials. Circular bubbles in the dusty regions are being hollowed out by the harsh radiations streaming out of the bluish star clusters. Pink regions are the re-emitted radiation from the gasses and dust that encircle newly forming star clusters.
  In the background, on the far right, the pale glow of a companion oval galaxy shines orange.
  The Hubble ST images of M51a & M51b resolve bright ‘blue’ dots in the leading edges of the spiral structures; and groups of both ‘blue’ and ‘pink’ dots in the compressed and dusty regions of the spiral arms. However, even at the large resolution, provided by the HST team, of 11,477 pixels across the entire (original) image; each pixel alone is estimated to represent a resolved field of view of a staggering 6.148 light years (1.88pc, 58.16 Tetra km or 36.14 Tetra mi) across.
  A preliminary estimate, derived from the pixel resolution, postulates that the size of the bright ‘blue’ star clusters, in the leading edge of the spiral arms, ranges between 18 to 37 light years across. At this size, these cannot be stars. These are instead assumed to represent clusters of young stars similar to those found in the Trapezium cluster in M42 of Orion . They would be collections of O and B type blue super-giants. Further it is noted that these clusters themselves are collected into groups. These cluster groups, sampled from the main dusty nurseries of the spiral arms of M51a, range in size from around 362 to 916 light years across; where emerging younger groups ‘pink’, may be of similar sizes, but are hidden by dust, and where some of those are detectable, range in size from 148 to 197 light years across.
  Measurements of the bubbles or voids from the ends of the dusty arm of M51a that is over M51b; shows that some of these clusters have cleared, by radiative outflow, spheroids of inter-galactic medium some 436 to 578 light years across.
  These are small structures in the context of a galaxy, but are truly enormous and are a challenge to our models and understanding of star formation.
NGC2207 + IC2163_hs-1999-41-a-full_990w
10 - NGC 2207 + IC 2163
HST 1999

NGC5866 (1) a lenticular galaxy_HST_990w
10 - NGC 5866 (1) The Spindle Galaxy a relatively bright lenticular galaxy, type SO, viewed edge-on in the constellation Draco @ 50 ± 3 Meg light years (15.3 ± 0.7 Meg pc) distant.

  The discovery of NGC 5866 (the modern classification number) is attributed to either Pierre Méchain or Charles Messier in 1781. Because of some uncertainty here, the Messier classification number, M102, is not strongly associated with the galaxy, although it is used by some astronomers. NGC 5866 was then later independently found and catalogued by William Herschel and his sister in 1788.
  A lenticular galaxy is a mixed morphological definition, i.e. based on shape, and lies intermediate between an elliptical galaxy and a spiral galaxy.
  NGC 5866 appears to have very little gas in its central regions, and so shows no recent star formation. The spectrum of its stars, from the hazy region, indicate that they are old. Because it is seen edge-on, whether it has expected single or multiple 'rings' of residual dust, cannot be determined; nor the possible presence of a 'bar' across its central bulge (Which would re-classify it as a type SBO galaxy).
  The lack of star forming materials (gas) and the brightness of NGC 5866; suggests to some theorists that this is due to resent mergers of spirals, that has left the system brighter and deficient in star forming gas. But in general, the formation of galaxies, and of lenticulars in particular, is not as yet fully understood, and theoretical models are inconsistant. Much remains to be investigated.

  This Hubble Space Telescope image of the lenticular Spindle galaxy is quite remarkable in more ways than just another image of a odd galaxy. A careful look at the image begins to reveal some important and subtle features that the image realises, but some that are often overlooked. For one, it views a distant galaxy. At around 50 million light-years; that’s quite distant. At that distance, individual stars are not resolvable on the same scale of the galaxy viewed. They are far too small. A nova or super-nova may be visible as a bright patch for a short time; but that is not a usual star. The first point being that, at the distance of the NGC 5866 galaxy, the only stars that can be discerned are the summation of the collection of stars seen as an opaque elliptical haze around the wispy dust lane of the galaxy.
  The second subtlety, is that there appear to be stars in the image. These are, in general, the round dots in the image. It would take careful consultation with a star catalogue to sort out which are the stars and which are not; and perhaps for some doubtful items, further (let us say) spectroscopic analyse to fine-out the stars from other things. But the real point here is; that any star that is captured in this image is a star from our local Milky Way galaxy, and will all lie close in the foreground when compared to the distant NGC 5866 galaxy.
  With respect to this image; once we have left the environs of our own local galaxy, there are no more stars to see. This then brings up the third subtlety; apart from the few bright dots of stars that pollute this image in the foreground; everything else discernable in the image, are in the main, galaxies.

NGC 5866
   Around the edge-on view of the grey and brown dust lane of the galaxy, can be seen an opaque elliptical haze that defines the limits of the oblate spheroid of stars that surround the galaxy. (On some display screens the opaque elliptical haze may show some faint banding; this is due to aliasing of the image pixels by the screen; and has nothing to do with the galaxy itself.)
   In-line with the grey and brown dust lane, and at its ends; a whiter and brighter haze of stars define the limits of an edge-on disk of stars encircling the dust lane.
NGC5866 (2a) a lenticular galaxy_HST_sub-br2_990w
10 - NGC 5866 (2a) The Spindle Galaxy a lenticular galaxy with detail of its dust band viewed edge-on

  A horizontal view of the edge-on grey and brown dust lane inside the galaxy NGC 5866. There are three things of main interest here.
  The first is that the dust is seen through a similar edge-on thin haze of stars that surround it. This is more distinct at the ends of the dust lane, where the haze of stars obscures the outer edges of the dust circle, much like a thickening mist.
  The second is that the core of the galaxy, composed of old stars, glows orange, central behind the grey and brown dust lane.
  Thirdly, the edge-on grey and brown dust lane itself is not flat and even, but shows wispy filaments that indicate some dynamic activity; analogous to, but necessarily different to, the activity of clouds we see on earth. These filaments that give the grey and brown dust lane additional thickness; are also similar in shape , and perhaps dynamic as well, that form the wisps of pink new stars in the galaxy M51a - NGC 5194 (The Whirlpool shown above).
NGC5866 (3) a lenticular galaxy_HST_sub-a_990w
10 - NGC 5866 (3) The Spindle Galaxy a lenticular galaxy viewing an end of its edge-on dust band

   At the highest resolution available from the HST image here obtained; an end portion of the edge-on grey and brown dust lane of the galaxy NGC 5866 is shown, together with polluting foreground stars (especially the bright star in the middle of the image) and an accompanying spiral galaxy of NGC 5866’s Draco group.
   Throughout the dust lane appears bright bluish-white regions; as spots in the dust. These must be regions of some star formation, and of clusters of stars, but on a much smaller scale than that demonstrated by M51a - NGC5194 (The Whirlpool shown above). Although the core of the main ellipsoid of stars of NGC 5866 may be deficient in gas to form new stars, the dusty ring area would still seem sufficiently mixed to contain material for star generation; as these bluish-white regions seem to show.
10 - NGC 2787 a barred lenticular galaxy in Ursa Major
HST 2002

10 - NGC 4150 elliptical Galaxy
HST 2010 - NASA, ESA
RM Crockett (University of Oxford - UK), S Kaviraj (Imperial College London and University of Oxford - UK), J Silk (University of Oxford), M Mutchler (Space Telescope Science Institute - Baltimore), R O'Connell (University of Virginia - Charlottesville) and the WFC3 Scientific Oversight Committee

10 - NGC 4150 heart of elliptical Galaxy (Image sharpened-20 by author)
[& browser-compressed - i.e. the image shown is 3 times smaller than the actual size of the file-image]

HST 2010 - NASA. ESA
RM Crockett (University of Oxford - UK), S Kaviraj (Imperial College London and University of Oxford - UK), J Silk (University of Oxford), M Mutchler (Space Telescope Science Institute - Baltimore), R O'Connell (University of Virginia - Charlottesville) and the WFC3 Scientific Oversight Committee

NGC4038+4039_(01)_antennae_black+white_large_r+80_a2_600x305 10 - NGC 4039 (left) + 4038 (01) The Antennae in black + white

(Unknown source)

10 - NGC 4039 (left) + 4038 (02) The Antennae galaxies in colour. Two galaxies in collision. The trail of stars from each galaxy a product of the gravitational interaction; and in the shape of insectile antennae from which the name is derived.


  Computer simulations for the tidal action that genetated the 'antennae' agree well with the observations. Astronomers estimate that the gravitational interaction began some 200-300 Meg years ago.
10 - NGC4038 (lower left) + 4039 (upper right) (04) The Antennae Galaxies @45-Meg light years distant. A type SB(s)m-pec(left) and SA(s)m-pec (pec = peculear galaxy)

10 - The left side of the disturbed core of NGC 4038 (07). The birth of bright blue super clusters in a burst on the upper edge of the core. The core glows with old orange stars and is strewn with brown whisps of its dusty interior.

NGC4038+4039_(06)_The-pink-of-HII-reflection-from the gas-&-dust-and-the-white-of-densly-packed-stars
10 - At the right of the disturbed core of NGC4038 (06). The pink of HII (ionised hydrogen) reflection from the excess gas around the new stars & dust swirls of mixing cores links with the white of densly packed stars.

10 - The remnant of the core of NGC 4039 glow in orange (08). On the bottom edge, Super-clusters emerge from lanes of dust disturbed by shock.

10 - The right side of NGC 4039 fades into space (21). Beauty in the beast-1.

10 - New stars spiral out of the right edge of NGC 4038 (22). Beauty in the beast-2.

10 - At the lower left of NGC 4038 (30) a small group of super-clusters migrates out of the parent galaxy.

10 - The Stars like Dust - NGC 4038 + NGC 4039 (bottom tip) (34B)
Near the central cusp at the galaxies edge; super-clusters & clusters fade-off to stars, then to empty space.

  This sub-image is here dedicated in memory to the Russian born biochemist and Science Fiction author Dr. Isaac Asimov, whose writings inspired, in particular, the imaginations of the technologists of the late 20th Century.

The stars, like dust, encircle me
In the living mists of light;
And all of space I seem to see
In one vast burst of sight.
The Stars like Dust, (1955) Pg32 - Isaac Asimov

  The above verse refers to a ‘Jump’ in hyperspace, from the outer regions in towards a more central region of the galaxy, where the abrupt change in perspective would fill the sky with closer packed stars. An imaginative feat of technology we have not, as a techno-species, as yet attained. Having no telescopes probing from the inner regions of the galaxy; views near the central cusp of NGC 4038 + 4039 make an as imaginative a leap from the beginning of the 21st Century.

  Marooned of Vesta, The Currents of Space, The Caves of Steel, The End of Eternity, The Naked Sun, The Martian Way, Earth is Room Enough,
I Robot, The Rest of the Robots, Foundation, Foundation and Empire, Second Foundation, Prelude to Foundation, Foundations Edge,
Fantastic Voyage, The Gods Themselves, The Bicentennial Man, Through a Glass - Clearly, Space Ranger, Pirates of the Asteroids,
The Big Sun of Mercury, Pebble in the Sky,
Buy Jupiter, The Moons of Jupiter, Nightfall One, Nightfall Two, Nine Tomorrows,
Oceans of Venus, The Early Asimov Vol 1 - 2 & 3, Asimov's mysteries, Today and Tomorrow, Towards Tomorrow,
The Tragedy of the Moon, The Planet that Wasn't.
[ This is not a definitive list. ]

galaxies_UGC10214-The Tadpole Galaxy_HST-ACS-2002_hs-2002-11a_02_r90_450w 10 - UGC 10214 - The Tadpole Galaxy; a galaxy in collision showing a 'tadpole tail', gravitationally ejected by the encounter, forming young blue star-clusters from the displaced gasses and dust.

HST - Advanced Camera for Surveys (ACS) 2002; NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA - (Image STSci-PR02-11a)

galaxies_UGC10214-The Tadpole Galaxy_HST-ACS-2002_hs-2002-11a_02_r90_section-A_990w
10 - UGC 10214 - The Tadpole Galaxy in closer view. Fragmented, the smaller bluish galaxy that rides above the large spiral (shown to the left), is deduced to be the one responsible for creating the disturbance. Having passed through the large spiral in the past, it will eventually be captured and will merge with the gravitationally stronger large spiral, within the next few 100 million years or so.

HST - ACS 2002; NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA - (Image STSci-PR02-11a)

galaxies_UGC10214-The Tadpole Galaxy_HST-ACS-2002_hs-2002-11a_02_r90_section-B_990w
10 - A magnificent back drop of galaxies studs the image (above) of the Tadpole Galaxy (UGC 10214)
HST - ACS 2002;
NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA - (from Image STSci-PR02-11a)

10 - UGC 10214 - The Tadpole Galaxy. Another background of galaxies; through a slice of the 'tail'.

10 - Seyfert radio galaxys - The Sextet
(Unknown source)

  The Seyfert type galaxies emit strongly in the radio spectrum (below the wavelength of light).
10 - NGC 1232 intermediate spiral galaxy + NGC 1232A tiny satellite galaxy in Eridanus (The River)
ESO VLT and FORS; 21st September 1998; U (360 nm; 10 min), B (420 nm; 6 min) and R (600 nm; 2:30 min) during a period of 0.7 arcsec seeing.

  An active and dusty galaxy, the large spiral is closer to us than the small companion. Old stars show orange and reflective h-red in the central regions; with the dusty spiral arms in green. New bright O-type star clusters are seen forming in the shock-fronts of the spiral arms.
10 - NGC 1232 intermediate spiral galaxy + NGC 1232A tiny satellite galaxy in Eridanus (The River)
ESO La Silla Observatory in Chile, IDA Danish 1.5m through three filters (B-900s,V-400s,R-400s) R. Gendler & A. Hornstrup.

  The NGC 1232 spiral in near ultra-violet shows the difference between the active white-blue star forming regions and the dusty star strune lanes in between. NGC 1232 is estimated to be 65 Meg light-years away; and the tiny spiral behind 68 Meg light-years away (NASA IPAC 1988); a difference of some 3 Meg light- years; or some 15 diamaters of the larger spiral galaxy away. With an estimated diamater for NGC 1232 of ~200K light-years, NGC 1232A at its widest, scales up to be 29K9 light years wide; a dwarf galaxy.
  A componant of unseen gravitational dark matter is computed to be present around NGC 1232 in order to explain the dynamical behaviour of the galaxy.
10 - M82 - NGC 3034 an irregular, is called the Cigar galaxy; and M81 - NGC 2961 - a spiral galaxy.
DSS Consortium

  The galaxies are seen as they lie in the constellation Ursa Major (the Great Bear) and estimated to be about 300,000 light-years apart from each other. M82 is estimated to be 3.5 ± 0.3 Meg pc (11.5 ± 0.8 Meg ly) distant.
  Astronomers have deduced that, about 600 Meg years ago, the two galaxies were in collision. The result of the collision was that it induced the formation of star clusters in both galaxies. However as will be shown, both galaxies were not effected in the same way. M81, the spiral (right), went on to produce star clusters the type and distribution of which are similar to those found in many other galaxies of that kind.
  In M82, classified as an irregular, the perturbation caused the star formation to evolve differently. M82 has now become a prototype for 'starburst galaxies' and is taken to define the phenomenon termed 'super cluster' formation.
M82_450w M81_450w
10 - M82 and M81
M82 - NGC 3034 the irregular 'starburst' galaxy; and M81 - NGC2961 - the spiral in Ursa Major
HST(left)- ACS 2006 (filtered for detail) + Spitzer ST(right) - (infra-red) 19-12-2003; respectivly

M81_Spiral Galaxy_hs-2007-19-a_2_990w
10 - M81 - Spiral Galaxy
HST 2007 19-a

10 - M82 - NGC 3034 the irregular 'starburst' or Cigar galaxy in Ursa Major @12 Meg-ly
HST ACS 2006 (filtered for detail)
10 - M82 The central drivers; A Ring of Black Holes
HST ACS 2006

  A Chandra X-ray image is superposed to show the position of the circle of Black Holes discovered in the centre of M82. Computer simulations indicate that super-clusters in dense compact regions, similar to the heart of M82, have star densities sufficient to cause collisions and mergers of individual stars. These conglomerates grow by further gravitational collection of nearby stars. These massive stars quickly evolve to supernova and collapse into black-holes. The black holes then continue the collection process to form holes of intermediate mass (800 - 3,000 M-sol), as discovered by Chandra (2010).
  The obvious opposing cones of material ejected from the central region of M82 is not as yet clearly explained by the astronomical community. Described as bi-polar outflow of material from the heart of M82 only defines part of what is observed. Data presented in 1993 (Gaffney, N. I., Lester, D. F., and Telesco, C. M.) suggests that a super massive black hole (~30 Meg sol) resides at the heart of M82. It would then be assumed that the black hole would be responsible for this bi-polar outflow. However the more recent work, by the Chandra team and others, begins to show quite clearly that there is no single black hole at the centre of M82; but rather a tight ring of intermediate mass black holes.
M87 Jet - A single black hole is postulated to be the cause of the jet imaged from the M87 galaxy @65Meg-ly distant. Synchrotron radiation emission is detected in the 5,000-ly long stream.
HST near infra red.
   The single mass super black hole hypotheses, while elegant in terms of concentrated mass, presents a problem in the result it would produce in bi-polar outflow. One would expect a tight beam of material to be ejected; the more massive the hole, the tighter the beam (See image M87 - left). The bi-polar outflow observed from M82 does not exhibit this characteristic. The outflow is quite clearly in two quite widely spread cones, which angle away from their common axes by over 50°.
   This behaviour would perhaps be better explained by a ring of orbiting intermediate mass black holes; each hole itself generating bi-polar outflow. The combined effect of their outflow, would be conical. This hypothesise however, makes some assumptions that would need testing. It assumes that the majority of the black holes have their axis of rotation somewhat aligned with the axis of rotation of M82. The spread of skew of their axial alignment contributing to the openness of the cone. The question being, is any alignment possible and by what mechanism?
   The existence and alignment of the ring of black holes suggests conservation of momentum derived from material of the galactic disk. But the alignment of the black holes themselves is derived from the stars within the super clusters in which they are formed. It seems difficult to conclude that the super clusters themselves would have any axial rotational bias that could be inherited by the holes. So that limits the argument of conservation of momentum to the ring only. A different mechanism would need to be invoked to explain the axial alignment of the black holes.
   The debate continues. M82 is under investigation by many teams of astronomers using some of the most sophisticated earth and space based telescopes, in all ranges of the electromagnetic spectrum, that have come on-line in the last decade. M82 is just close enough at 3.5 ± 0.3 Meg pc (11.5 ± 0.8 Meg ly) to yield image detail of supernova remnants, and other fine detail, using Very Large Baseline Interferometery (VLBI) now not only available to radio telescopes, but applicable to the new generation of optical instruments as well.
   A spin off from these investigations will also tell us more about our own Milky Way Galaxy, the heart of which, although closer than M82, is much obscured by intervening gas and dust because of our viewing location in an outer arm and in the plain of the disk of our Milky Way Galaxy. It appears that a similar pattern of a ring of orbiting black holes would also better apply to the centre of our own Milky Way galaxy, and not a single black hole as is the currently accepted theory. – 18th August 2012
10 - NGC 253 - The Sculptor Galaxy (Silver Dollar), a spiral 'starburst' galaxy. A highly processed image resulting in a mosaic composit from the infra-red; detailing the bar and the spiral features of the galaxy.
Atlas Image [mosaic] 2 June 2005; obtained as part of the Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center, California Institute of Technology, funded by NASA and the US National Science Foundation.

NGC 253 - Sculptor Galaxy (Silver Dollar)_ESO INAF VLT Survey Telescope (VST)_01_990w
10 - NGC 253 - The Sculptor Galaxy (Silver Dollar), a spiral 'starburst' galaxy (as shown above); here highlighting the bright stars in 'starburst'.
INAF VLT Survey Telescope (VST) 16 December 2011 - ESO; A. Grado + L. Limatola; INAF Capodimonte Observatory.

NGC3370-Warped-Spiral-Galaxy-Edge-On_HST2003_NASA-The-Hubble-Heritage-Team_A-Riess(STScI)_hs-2003-24_600w 10 - NGC 3370 - A warped Spiral Galaxy edge-on

HST 2003 - NASA, The Hubble Heritage Team and A. Riess (STScI)

10 - Spiral Galaxy 0313-192 with a wide angle view of its associated giant Radio Jets; matter ejected from the galaxy by a massive black hole at the heart of the galaxy.

HST 2003 - NASA, NRAO, AUI, NSF and W. Keel (University of Alabama, Tuscaloosa)
10 - HCG 92 Stephan's Quintet in Pegasus
Recessional velocity of the Galaxies = rv km/sec

NGC 7317 Bottom right elliptical El-rv=6,646;
NGC 7318B(left)+A(right) Colliding pair Sbc-rv=5,749_B, Sc-rv=6,663_A;
NGC 7319 Top barred spiral Sbc-rv=6,710;
NGC 7320 Lower spiral Sd-rv=791.

HST WFC3 - filtered ultra-violets - NASA, ESA, and the Hubble SM4 ERO Team

  The view accross the image, from the left to the right edges of the galaxies; is about 300,000 light-years (92 kpc).
10 - NGC 7318B (top) + NGC 7318A (bottom) Colliding galaxies in HCG 92, Stephan's Quintet in Pegasus
HST 2009 (filtered)

Cartwheel Galaxy a lenticular about 500 Meg ly away in the constillation Sculptor HST - Kirk Borne (STSci) & NASA_900w
10 - Cartwheel Galaxy a lenticular about 500 Meg ly away in the constillation Sculptor
HST - NASA; Kirk Borne (STSci)

10 - Hickson compact Group 87

HST 2001 22-d - NASA, AURA (STScI)
galaxies_AM0644-741_Ring-Galaxy_300Meg-lt-years-away_150,000-light-years-in-diameter_HST_2004_02_640w 10 - AM 0644-741 Ring Galaxy. 300Meg light-years away; 150,000 light-years in diameter

HST 2004

10 - Hoag's Object - An unusually rare 'Ring' galaxy viewed 'ring on' (although some dispute that the ring itself may be slightly tilted) toward the constellation of Serpens.
HST WFPC2 around 2002 - Filtered to emphasize the differences between the nucleus and the ring, thus allowing the display of faint reddish objects in the apparent gap.

  At 183±8 Meg pc (600±30 Meg light years) distant (1974 estimate), the HST is only able to resolve objects on a scale considered as 'super-clusters' of stars within the galaxy. The inner core appears to be an aged elliptical about 5.3±0.2 kilo pc (17±0.7 kilo ly) in extent; while the ring which displays bluish 'super-clusters', which are therefore much younger that the central region, and hence provides the main question in debate as to its origins, has an inner diameter of 24.8±1.1 kilo pc (75±3 kilo ly) and an outer diameter of 39.9±1.7 kilo pc (121±4 kilo ly), overall a slightly larger galaxy than the Milky Way.
   That a similar 'ring' galaxy appears in the gap (although there are some differences); and a possible 2 others appear behind the ring itself, are a bonus to a remarkable image.
NGC 4650A is a S0^a pec polar-ring lenticular galaxy in Centaurus;HST 4 May 1999; J. Gallagher(UW-M) et al. & Hubble Heritage Team (AURA+STScI+NASA)_hs-1999-16-a-full    There is still some discussion as to the type of grouping of the central region of Hoag's Object. Although it appears as a circular elliptical galaxy, some think that it may be oval, with its long axes towards us, with the ring around its equator. Others propose differently, that the inner galaxy spins with its axis pointed at the edge of the ring. Some classify it as a ‘polar’ galaxy (See image of 'polar-ring' alongside).

NGC 4650A - A S0/a pec Polar-ring lenticular galaxy in Centaurus
HST 4 May 1999; J. Gallagher(UW-M) et al. & The Hubble Heritage team (AURA+STScI+NASA)

   Whatever it is; the main problem is explaining the origin of the ring, which at this time, remains speculative. The general idea is, that when galaxies collide, the shock of the interacting galaxies interstellar medium (gas and dust) is usually collected by the gravity of the larger galaxy, and the shock waves spread, causing starburst (star-birth) on a grand scale (meaning many large ‘blue’ stars) in ‘super-clusters’, where the waves ripple out. In general cases, there is usually some mark of this passage left in the core of the larger pierced galaxy. There is no obvious evidence of this in Hoag's Object. There are no near-by galaxies to account for it either. (But the far galaxies seen behind the object may eventually be part of the puzzle, but no one has yet accounted them into the solution. It’s all to do with the passage of time.) One current idea is that the wonderer was absorbed on collision.
   Because of its distance, just beyond the reach of existing telescopes (although they are catching up) for convenient analyses, there is evidence of starburst continuing in the non-circular swirls of shock in the ring. The evident ‘blue’ O type stars constrain the time problem. Their lifetime is counted in 100’s of millions of years, rather than billions (Giga). The shock wave however, is not chasing radially directly across 23 thousand light-years of ring, but is evident as spiral structures within the ring. As everything is spinning, non-liner disturbances are expected. The shock waves are mechanical, leisurely in terms of galactic age, and not light-speed. Calculations by some astronomers place the date of the rings disturbances as beginning some 2-3 Giga years ago.
   In the gap, faint red ‘super-clusters’ of old stars appear in the halo of the inner galaxy.
   The object is named after Art Hoag who accidently discovered it, and described it in 1950; the object not appearing in any previous catalogue. Thought at first to be a planetary nebulae; Hoag dismissed that idea on grounds of size; its unusual position outside the galactic environment in which most other planetary nebulae are found; and on spectral analyses of its ring, or ‘halo’ as he called it, that did not yield the expected gasses found in planetary nebulae. Although the circular ring was suspect to optical diffraction to being the effects of a gravity lens, Hoag concluded there was insufficient mass for this effect. He termed it a ‘pathological’ galaxy.
   It is interesting to note that if the tiny ring type galaxy viewable in the gap is estimated to be of similar size to its foreground companion, then its distance is some 19 times further away, at a very approximate 10.3 Giga light years (Hubble constant not applied); ruling out the possibility of any interaction in the past, between them.
galaxy_dwarf spheroidal galaxy in Fornax (used in Fermi's dark matter search)_ESO_Digital Sky Survey 2_635607main_eso1007a_set-02_990w
10 - Dwarf spheroidal Galaxy in the constillation Fornax.
One of 10 such dwarfs used by the NASA's research team taking data from the Fermi Gamma-ray Space Telescope in the search for dark matter within the local group of galaxies - With negative results in April 2012.
ESO - Digital Sky Survey 2

10 - I Zwicky 18 - A newly formed infant galaxy; or is it?
HST STScI-2004-35 (1 Dec); NASA, ESA, Y Izotov (Main Astronomical Observatory, Kyiv, UA) + T Thuan (Uni of Virginia)

Gravitational lensing example_NASA, ESA, Z Levay + A Field (STScl)_STScl-PRC11-04_web_print_SetB_950w_730h 10 - Gravitational lensing example

NASA, ESA, Z Levay + A Field (STScl); STScl-PRC11-04

10 - Gravitationally Lensed
High - Redshift Galaxy Candidates (Circled)

HST; NASA, ESA, S Wyithe (Uni of Melbourne), H Yan (Ohio SU), R Windhorst (Arizona SU), + S Mao (Jodrell Bank Center for Astrophysics, + National Astronomical Observatories of China); Ack: G Illingworth + R Bouwens (Uni of California, SC), + HUDF09 Team

  Composite the Hubble Ultra Deep Field. Green circles candidate galaxies at a redshift of z~8, while higher-redshifts are circled in red. Spectroscopic confirmation of estimated distances still necessary.

  About 20 to 30 percent of these high-z galaxy candidates are very close to foreground galaxies, which is consistent with the prediction that a significant fraction of galaxies at very high redshifts are gravitationally lensed by individual foreground galaxies. Confirmation of these ideas await the the launch of the James Webb Space Telescope, or similar.
Gravitationally Lensed High-Redshift Galaxy Candidates_NASA, ESA_web_print_1000w_744h
Abell 1689 Galaxy Cluster_HST ACS 2002 - NASA_hs-2003-01-a_990w
10 - Abell 1689 Galectic Cluster. One of the densest clusters of galaxies known. The consentration of mass of the cluster is high enough to cause grevitational lensing of the light of further galaxies to appear as arked streaks in a circle around the centre of mass of the Abell cluster.
HST ACS 2002 - NASA N Benitez + H Ford (Johns Hopkins University), M Clampin + G Hartig (STScl) G. Illingworth (Link Observatory + University of California - Santa Cruz), the ACS Science Team & ESA

Abell 2218 cluster of galaxies in Draco @ 2 billion lys. Mass produces gravitational lensing (arc-shaped features) of objects 5 to 10 times farther than cluster - HST_hs-2000-07-b-full_990w
10 - Abell 2218 Galetic Cluster in Draco @ 2 billion lys distant. Mass produces gravitational lensing (arc-shaped features) of objects 5 to 10 times farther than the lensing cluster
HST 2000

10 - Abell S740 an Eliiptical galaxy and gravitational lens

  Within the galaxy cluster NGC 2218 is the massive eliptical galixy Abell S740 - It is at the heart of the Abell cluster. It is postulated that invisible Dark Matter together with the visible matter of the galaxy, contribute to make this cluster a very strong gravitational lens.
10 - SDSS J1004+4112 - Multipal gravity imaging of a far quaser (Quasi Steller Object).
HST 2006 23-a

  The 4 white 'dots' around the orange eliptical galaxy are images of the same quaser.
Dark Matter
It is staggering to realise that, for all our technological achievements to date,
We have done so with theoretical models that understand only
About 5-6% of the matter and energy of the conceived cosmos.
Or so it is placed. How much more there is to learn.

10 - Caption

The Cosmos

Hubble Deep Field (HDF) 1 an assortment of at least 1,500 galaxies at various stages of evolution as far back as ten billion years ago - HST WFPC2 342 exposures 18++28-12-1995_hs-1996-01-a-full_990w
10 - Hubble Deep Field (HDF) 1; Dec 1995.
HST WFPC2 342 exposures 10 hours 18++28-12-1995

  An assortment of at least 1,500 galaxies at various stages of evolution as far back as ten billion years ago
  A selected view due North along the axes of the galectic plain, near Polaris the pole star that avoids, as best possible, contamination by stars from the local galaxy star field
Hubble Deep Field (HDF-1)sub-set Red shifted galaxy considered as most distant by KLanzetta (SUNY Stony Brook)&NASA26-06-1996_HST_WFPC2_342exposures18++28-12-1995_990w
10 Hubble Deep Field (HDF-1) sub-set; Dec 1995.
Red shifted galaxy (circled) considered as most distant by K Lanzetta (SUNY Stony Brook) and NASA 26-06-1996
HST WFPC2 with 342 exposures over 10 days between 18++28-12-1995

Hubble Deep Field South (HDF-S) A second corroborative sample of galaxies down a 12 billion ly time corridor with a quasar in the field - HST WFPC2 10 days 10-1998_hs-1998-41-b-full_990w
10 - Hubble Deep Field South (HDF-S). 1998.
HST WFPC2 10 days 10-1998

  A second corroborative sample of galaxies down a 12 billion ly time corridor with a quasar in the field. A view along the Southern axis of the galectic plain with similar constrainsts as for the HDF-1
   These HST DF images hold some staggering and subtle realisations. One views, looking through the ‘straw’ of the visual field of one of the planets most sophisticated telescopes, a ‘dot’ on the inner extensive sphere of the viewable cosmos. Every smidgen of light collected on these images represents unresolved galaxies beyond the 12 Giga light-year resolution of the HST. A conservative calculation estimates that there are around 100,000 unresolved galaxies in the background field of these images; may be even more, but so what? Very busy ‘dot’s indeed. We look back in time, towards the beginning of time, and see an ever expanding universe. It gets bigger as we look deeper; a paradox of perspective and the rules of relativity and of the speed of light. It is good that it is so, otherwise we would not be here to observe it. That ‘we’ are here to observe it, is a statement from the Anthropic principles of cosmology. It suggests that we can only exist to observe, in a non-hostile universe. It is a philosophical construct that leads to the paradox that when stated the other way around; we will never know if a different universe exists, because it could be hostile to the existence of life, and we could not exist in it. Which raises the point of Olbers's paradox.
   Olbers's paradox is based on a thought experiment, in simplicity, ‘Why is the sky dark at night?’. If there are all those stars ‘out there’, why isn’t it bright at night? The answer, provided by Einstein and Hubble, is that space-time is expanding; and the further away an object (a galaxy, as used by Hubble), the faster it is receding from our relative position (on earth, in the Milky Way galaxy) in space-time. The HST DF continues the confirmation of this fact. If it were not true, we would fry to death by starlight. Space-time and the universe expands.

   HDF-1 & HDF-S – An interesting footnote to these two images, and one that has surprisingly remained unemphasized elsewhere; is that these two images represent, at the date they were taken, the most profound images ever made by human civilization. They represent a mile-post to species homo sapiens, on their way as an adolescent technological civilization, to join the ever elusive cosmic smattering of galactic civilizations. However tenuous that idea may be today, just facing these images shifts doubt to virtual inevitability.

Return: Andromeda - Patches through a Straw

10 - 20 years of Deep Field study - Ground to Space.
Illustrating how our view into the past has change as our existing technologies advanced.
The proposed 2018 Next Generation composite 18-mirror, 6.5 m (21 ft) diameter, James Webb Space Telescope should take our understanding of the beginnings of our 'Atoms from within the Cosmic Globe' to even more revealing and startling depths.

HST eXtreme Deep Field (XDF)_NASA, ESA, G Illingworth, D Magee, + P Oesch (Uni of California, SC), R Bouwens (Leiden Uni), + HUDF09 Team_STScI-2012-37(Sep 25)B_1200w_1096h
10 - Hubble eXtreme Deep Field (XDF), Sub-image. September 2012
The few bright round spots with striations are polluting stars in the near field from the MW galaxy.
HST, STScI-2012-37(Sep 25)B; NASA, ESA, G Illingworth, D Magee, + P Oesch (Uni of California, SC), R Bouwens (Leiden Uni), + HUDF09 Team

  Hubble started the Deep Field survey in 1995, with a selected best uncontaminated view along the North axes of the MW galaxy, a small area of space in the constellation Fornax. After the HST service updates by the SST in 2002, NASA/ESA revisiting the same area, to produce the Hubble Ultra Deep Field survey using images from 2003 and 2004. After the last HST service updates by the SST in 2009, NASA/ESA ran the Hubble Ultra Deep Field 2009 (HUDF09) program, updating the field data with images taken with the newly serviced HST Advanced Camera for Surveys (ACS) and in IR with the Wide Field Camera 3 (WFC3) and published the results later that year.

  The Hubble eXtreme Deep Field (XDF) survey 2012, now uses additional data, from over 2,000 images taken over the past decade that represents a total exposure time of 2 million seconds (50 days).

  The Hubble eXtreme Deep Field (XDF), Sub-image shown, is a small sample of far galaxies taken from the main image. It is estimated that the youngest galaxy viewed in the XDF formed just 450 million years after the cosmic big bang.

HST HUDF 2014_NASA, ESA, H Teplitz + M Rafelski (IPAC,Caltech), A Koekemoer (STScI), R Windhorst (Arizona SU), + Z Levay (STScI)_STScI-2014-27(Jun 3)_large_web
10 - Hubble Ultra Deep Field (HUDF) 2014. June 2014
The few bright round spots with striations are polluting stars in the near field from the MW galaxy.
HST, STScI-2014-27(Jun 3); NASA, ESA, H Teplitz + M Rafelski (IPAC,Caltech), A Koekemoer (STScI), R Windhorst (Arizona SU), + Z Levay (STScI)

  The Hubble Ultra Deep Field (HUDF) 2014, updates the composite with separate exposures taken over 2002 to 2012. Emphases has been given by the addition of ultraviolet (UV) frequencies, frequencies missing in earlier surveys that were giving cosmologists difficulty to reconcile aspects of the development of the early galaxies of the cosmos.

Chandra-Deep-Field-South_A-Pool-of-Distant-Galaxies_7Nov2008(U+V),Archive(R)_VLT- VIMOS_MPG-ESO2.2mWFI_ESO-M-Nonino,P-Rosati+GOODS_eso0839a_990w
10 - Chandra Deep Field South. A Pool of Distant Galaxies. ESO. 7 November 2008

   Redshift: z = 3.7
   Position (RA): 3h 32m 27.63s
   Position (Dec): -27° 45' 4.71"

(U+V), Archive (R): Ultra-violet U (40 hours), VLT VIMOS; Optical V, VLT VIMOS; Optical R, MPG/ESO 2.2m WFI;
ESO; Mario Nonino, Piero Rosati and the ESO GOODS Team

  To assist the worldwide community of astronomers investigate the formation and evolution of galaxies, the Great Observatories Origins Deep Survey (GOODS) collaborative team continually re-surveys two particular areas of the sky over the years. Field South is one of these. The fields are observed with ground and space facilities, at all available frequencies, from X-ray, through optical and to radio wavelengths.

  Observations in the U-band, the boundary between visible light and ultraviolet (UV) are challenging; the Earth's atmosphere becomes progressively more opaque out towards the UV. Specific sites are better suited and equipped to see in the U-band, such as ESO's Paranal Observatory in the Atacama Desert; particularly VIMOS on ESO's Very Large Telescope (VLT).

  Chandra Deep Field South combines ~40 hours of observations with the VLT on the VIMOS in U-band and VIMOS R-band images from a large number of archival images totalling 15 hours of exposure. The Wide-Field Imager (WFI) attached to the 2.2 m MPG/ESO telescope provided B-band images from part of the GABODS survey. The image is the deepest image ever constructed, at the time, from ground based observations in these wavelengths.

  The Garching-Bonn Deep Survey (GABODS) provides archival (to 2006) images from ESO's Deep Public Survey (DPS), WFI images in the U, B, V, R, I bands from sky regions defined as Deep1, Deep2 and Deep3.

  In the near-field, the few bright round spots with striations are polluting stars from the MW galaxy. Yes, all the rest are galaxies; represented in some false colours, the residual galaxies observed are a billion times fainter than can be seen with the unaided eye.

HST GOODS South_NASA, ESA, the GOODS Team, + M Giavalisco (Uni of Massachusetts, Amherst)_STScI-H-2016-39(Oct 13)-a-hires-B_990w_1620h
10 - Hubble GOODS South. October 2016 [Composite image]
The few bright round spots with striations are polluting stars in the near field from the MW galaxy.
HST, STScI-2016-39(Oct 13); NASA, ESA, the GOODS Team, and M Giavalisco (Uni of Massachusetts, Amherst)

  This is the HST contribution to the Great Observatories Origins Deep Survey (GOODS) collaborative effort (See ESO Chandra Deep Field South image above for expanded data on this project), where the team continually re-surveys two particular areas of the sky over the years. Field South is one of these.

  According to Hubble and other GOODS deep-field researchers, about 90 percent of galaxies in the observable universe are too faint and too far away to be seen with present-day telescopes. Which means that there should be 10 times more galaxies beyond the view shown above.

  More powerful telescopes of the future may see deeper into this misty field.

Other Life in the Universe

It’s there all right; we just need to find it/them.
After all, we have only just started this quest.
A 300 light-year bubble is a miserly small volume, once compared to the true size of the task.
Or maybe, something will find us first?


Fringes of Reality

cosnet+paper tomes_04_rsz microsoft data centre+The Library, Calvin T Ryan Library, Uni of Nebraska, Kearney_John Lillis (flicker)_990w_176h
 European Southern Observatory, The (ESO)
Root Astronomical resource
 European Southern Observatory, The (ESO) - Public Images
ESO Observatories space and planetary image resource
 European Space Agency (ESA)
Root space technologies resource Europe
 European Space Agency (ESA) - Space in Images
ESA space and planetary image resource
 GEO600 (Germany) - Advanced Laser Interferometer Gravitational Wave Observatory
GW Observatory
 Institutet för Solfysik [Institute for Solar Physics (ISP)], Stockholm, Sweden; Royal Swedish Academy of Sciences
Land Sun Observatory, sunspots granulation
 KAGRA (Japan) - Laser Interferometer Gravitational Wave Observatory
GW Observatory (In Construction) Under Mount Ikeno, Kamioka mine, Kamioka cho, Japan
 LIGO H1 (Hanford) - Advanced Laser Interferometer Gravitational Wave Observatory
GW Observatory
 LIGO L1 (Livingston) - Advanced Laser Interferometer Gravitational Wave Observatory
GW Observatory
 NASA | NOAA - Earth at Night (Suomi NPP)
Composite image, a global view of Earth at night, compiled from over 400 satellite images
 National Aeronautics and Space Administration (NASA)
Root space technologies resource North America
 National Aeronautics and Space Administration (NASA) - Image Galleries
NASA space projects image resource
 Population Reference Bureau (PRB) 2012 World Population Data Sheet (PDF)
Earth population data set 2012
 SDO | Solar Dynamics Observatory, NASA
Space Sun Observatory, sunspots HD
 SOHO - Solar & Heliospheric Observatory; ESA, NASA
Space Sun Observatory
 STEREO - Solar Terrestrial Relations Observatory; dual space telescopes
Space Sun Observatory
 Super-Kamiokande Neutrino Observatory, Japan
Neutrino Observatory, Japan
 VERGO (Italy) - Advanced Laser Interferometer Gravitational Wave Observatory
GW Observatory
 World Food Programme - Hunger Map 2015
Under-nourishment in the population of developing countries as of 2014-16
 worldometers Population (live-active counters) - World population (est. UN) [^1]
Acess to, and live-active counters for, estimates of population, economic, resources and enviromental statistics from around the world.
  Paper Tomes
  1.   Ball, Robert S., Sir; The Story of the Heavens; LA Belle & Sauvage, 1890; ISBN Nil; Astronomy

  2.   Binney, James; Michael Merrifield; Galactic Astronomy; Prinston University Press, 1998; ISBN 0_691_92565_7; Astronomy

  3.   Bronowski, Jacob; The Ascent of Man; BBC, 1973; ISBN 0_563_17064_6; Sci History

  4.   Bryson, Bill; A Short History Of Nearly Everything; Broadway Books, 2003; ISBN 0_7679_0817_1; Science

  5.   Gribbin, John; Michael White; Einstein - A life in Science; Simon & Schuster, 1993; ISBN 0_671_71170_9; Sci History

  6.   Leslie, John, Ed.; Modern Cosmology & Philosophy; Prometheus Books, 1998; ISBN 1_750_57392_1; Science Papers

  7.   Moor, Peter; Discoveries and Inventions That Changed the World - The pioneers of modern science - What they did and why it matters; Quintet Publishing, 2002; ISBN 1_84543_097_2; Sci History

  8.   Rhodes, Richard; The Making of the Atomic Bomb; Simon & Schuster, 1986; ISBN 0_684_81378_5; Sci History

  9.   Thorne, Kip S.; Black Holes & Time Warps - Einstein's Outrageous Legacy; WW Norton & Company, 1994; ISBN 0_393_31276_3; Astrophysics

  10.   Various; Astronomy Today 4th Ed; E Chaisson, S McMillan, 2002; ISBN 0_13_091542_9; Astronomy

  11.   Zeilik, Michael; Astronomy 9th Ed - The Evolving Universe; Cambridge UP, 2002; ISBN 0_521_80090_0; Astronomy

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M81 spiral Galaxy, ir (top) optical (bottom) Red regions in arms represent emissions from dustier parts of galaxy where new stars are forming - Spitzer (infra-red) ST 19-12-2003_311w-312h 10 - M81 spiral Galaxy, infra-red (top) optical (bottom); Red regions in arms represent emissions from dustier parts of galaxy where new stars are forming
Spitzer (infra-red) ST 19-12-2003

HH46-IR young star with water & small organic molecules from galaxy @3,250Meg-ly at time of origin of life on earth - Spitzer (infra-red) ST 19-12-2003_311w-312h 10 - HH46-IR young star with water & small organic molecules from galaxy @3,250Meg-ly at time of origin of life on earth
Spitzer (infra-red) ST 19-12-2003

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A - (Eta) Carinae (104) INFRA-RED - VLT, HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO B - Carinae Nebula (106) INFRA-RED - VLT, HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO C - Carinae Nebula (108) INFRA-RED - VLT, HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO D - Carinae Nebula (110) INFRA-RED - VLT, HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO E - Carinae Nebula (112) INFRA-RED - VLT, HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO [Inside the green-box] - Carinae Nebula (029) INFRA-RED - VLT, HAWK-I (Infra-red) camera, Paranal Observatory, Chile - ESO A - (Eta) Carinae (103) VISIBLE - MPG 2.2 metre telescope, La Silla Observatory, Chile - ESO B - Carinae Nebula (105) VISIBLE - MPG 2.2 metre telescope, La Silla Observatory, Chile - ESO C - Carinae Nebula (107) VISIBLE - MPG 2.2 metre telescope, La Silla Observatory, Chile - ESO D - Carinae Nebula (109) VISIBLE - MPG 2.2 metre telescope, La Silla Observatory, Chile - ESO E - Carinae Nebula (111) VISIBLE - MPG 2.2 metre telescope, La Silla Observatory, Chile - ESO Outside-the-green-box%28default-not-covered%29
Close view of the Carinae Nebula (base image) - DSS; Light and Shadow in Carinae Nebula (sub-image) – NASA; AURA, STScI. Inside the Carinae Nebula. VLT infra-red - ESO
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