Observing the Glorious Hercules Cluster (M13)

The heart of the stunning Hercules Globular Star Cluster, M13. Image credit: ESA/Hubble Space Telescope and NASA.

The stunning Hercules Cluster (M13, NGC 6205) also called the 'Great globular cluster in Hercules' is perhaps the most famous globular cluster residing in the Milky Way's halo.  It is another astronomical jewel which is viewed best either using binoculars or a small telescope.

It was discovered by Edmond Halley in 1714, who noted that 'it shows itself to the naked eye when the sky is serene and the Moon absent.' Charles Messier catalogued this beautiful object in 1764.  At magnitude +5.8, it is possible from a dark site to observe it with the naked eye as a faint smudge of light.

When you look at this group of several hundred thousand stars (some astronomers reckon over a million!) it is amazing to think that it is over 25,000 light years away.... and it's still just on the outskirts of our galaxy!

M13 lies in the lower left shoulder in the constellation of Hercules, which itself lies between Bootes, Corona Borealis and Lyra, and is currently best seen in the late evening/early morning in mid northern latitudes.

How to find M13, the Hercules Cluster, located in 'the armpit' of the constellation.

Towards its centre of the cluster, the stars are about five hundred times more concentrated than in our solar neighbourhood. Such globular clusters contain some of the oldest stars in the universe, indeed, the age of M13 has been determined at about 12 billion years. However, this cluster, and other globulars, possess a peculiar attribute. M13, for example, contains one young blue star, Barnard 29, of spectral type B2 - totally at odds to the other constituent stars of the cluster.

Recent research by astronomers has located many such young blue and bright stars in ancient globular clusters - they've even been given a name - 'blue stragglers'!  It has been postulated that these young stars form from the merger (or collision) of two or more of the ancient stars in each densely packed globular cluster.  The result is one young and hot blue giant star.

M13 was selected in 1974 by Dr. Frank Drake of Cornell University and Carl Sagan as a target for one of the first radio messages addressed to possible extra-terrestrial intelligent life, and sent by the Arecibo Radio Telescope, Puerto Rico.   The message, when decoded, contains a graphic which includes the atomic numbers of the elements which make up deoxyribonucleic acid (DNA, the basis of all life on Earth), a graphic figure of a human, the height of an average human, the human population of Earth and a diagram of the Solar System.

The return journey time for a reply is 50,000 years, but bearing in mind the density of such globular clusters, it is now in doubt whether planets will reside in stable orbits around these ancient stars due to gravitational perturbations from their stellar neighbours.  Perhaps M13 wasn't such a good target candidate for a message after all!

However, do go out and enjoy one of the splendours of the northern night sky, you certainly won't be disappointed!

The Lost World of Barnard's Star

Artist's impression of the dim and very old red dwarf Barnard's Star from a hypothetical orbiting planet.  With new technology, if any such planet does indeed exist, then it should now be within our limits of detection.

ANDY FLEMING investigates the strange story behind the search for a planet orbiting Barnard's Star.  The search for exo-planets and it associated fabulous new technology and telescopes means that if such an elusive planet does orbit one of our Sun's closest neighbours, we should detect it as it orbits this very dim and old red dwarf star.

These days, it is accepted as a scientific fact that we live in a universe teaming with planets orbiting other stars. Indeed, as of today, there are 455 worlds that we know of orbiting stars other than our Sun. Detecting these planets has become a routine voyage of discovery engaging well tested and accepted methods.

The primary methods include radial velocity (Doppler displacement of spectral lines in the star's light due the star "wobbling" as it orbits the common centre of mass of it and its planetary companion), and the transit method (a dip in starlight as an exoplanet moves across the disc of the star thus reducing the amount of starlight). Other successful methods include astrometry, where miniscule changes in a star's precise co-ordinates in the night sky change over time, again due to its orbit around its stellar system's common centre of mass, and microlensing (a bending of light from a distant star due to foreground star's (and associated planet's) gravity.

Finally of course, there's the most spectacular method, and one that will become more important as detectors improve -- that of direct imaging, as in the case of Fomalhaut b and Beta Pictoris b, and associated stellar debris discs, as observed by NASA's Hubble Space Telescope.

However, it has always been this way.  Speculation has always run wild about whether planets orbit other stars, and by implication extraterrestrial life.  Indeed, the Roman Catholic monk Giordano Bruno was burnt at the stake in the year 1600 by the Vatican's Inquisition for his trouble of publicising the then heretical view that the universe was teaming with other worlds, and life.

Throughout the nineteenth centuries, theories of planetary formation, and that of the circumstellar discs from which they arise ebbed and flowed.  One particularly popular anthropocentric theory suggested that our star was unique in the Milky Way in possessing a solar system.  It had come about by an infinitesimally unlikely event -- a close pass of another star had ripped material out of our sun.  These strands eventually coalesced to form planets.

However, for resolution, the whole issue of exoplanets would have to await better technology and observations, not better theories.  After all, other stars are at gargantuan distances from the Earth, the nearest, Proxima Centauri is part of the Alpha Centauri triple system and is nearly 40 trillion kilometres distant. Whatever detection methods are employed, the effect of planetary companions will turn out to be almost infinitessimally small. 

Proxima Centauri is a dim red dwarf -- it's larger Sun-like siblings Alpha Centauri a and b are so bright that the pale reflected light from the parent star of any planetary companions would be completely emasculated by the star itself.  Even a Jovian mass giant would be a billion times fainter than the central star.  As an analogy of the immense technical difficulties involved with direct imaging, think of a dim candle placed a couple of metres from a floodlight viewed via a telescope from a vantage point a thousand kilometres distant.  What would be your chances of viewing the dim candlelight?

It's not surprising then, that the first "discovery," of an exoplanet, on this occasion via the technique of astrometry, turned out to be a false alarm.  The whole field of extra solar planet detection commenced in earnest thanks to one man -- Peter van de Kamp. Van de Kamp had been a professor at the University of Virginia for several years. In 1937 he went to Swarthmore College and became director of the Sproul Observatory there.

 Relative sizes of the Sun, Barnard's Star, and Jupiter. Being an M Class red dwarf, Barnard's Star is much smaller than our Sun, and is less than twice the diameter of  Jupiter.  Source: Wikipedia.

The next year he began a long-term search for very low-mass companions to stars. One of the first stars he put on the search program was a star called Barnard's star. Barnard's star is the second closest star system to our own, at 6 light years distance. The only one closer to us is the Alpha Centauri triple system mentioned above. Unfortunately, it's an M dwarf, so it can't be seen by the visible eye, but it can be easily seen with a small telescope.

Van de Kamp started collecting data on Barnard's star in 1938, and continued taking data for roughly 25 years. In 1963, he finally felt confident enough to present his first excruciatingly difficult astronometrical measurements. He and his colleagues were looking for variations of plus or minus 1 micron in the position of the star on a photographic plate!  In other words, they were endeavouring to measure the photographic centre of these little blurry dots on the photographic emulsions to a staggering 1 part in 100. They would have 10 people measure the same plates independently, and then try to average over whatever individual systematic errors they would introduce, to find the true photographic centre of the positions.

After looking at some 2400 plates, van de Kamp found evidence that there was a small 'wobble' in Barnard's star, which fit with the curve that would result if it was being orbited by a planet about 1.6 times the mass of Jupiter out at a distance of 4.4 AU.  The peculiar attribute of the star movement however was that it didn't correlate with a neat sine curve, which would indicate a roughly circular orbit like our won Jupiter's, instead, it had a little bit of a cusp to it.

However, most astronomers could live with a planet with a quite elliptical orbit, and Barnard's Star's planetary companion soon became the textbook example of an extra solar planet.  However, all was not well with the data used behind van de Kamp's momentous discovery, and ten years later in 1973, astronomer George Gatewood would reveal major flaws in van de Kamp's observations.

Gatewood had been undertaking his Ph.D. in astrometry at the University of Pittsburgh, and although reluctant at first, his professors were extremely keen that he study Barnard's star.  And so, unbeknown to him, Gatewood was to become reluctantly involved with a profound cosmic controversy.  While studying Barnard's Star, Gatewood undertook his own observations and measurements, using different telescopes, namely the Allegheny Observatory's Thaw Refractor, as well as some plates taken from the Van Vleck Observatory.

In total, Gatewood produced 240 plates, taken with different telescopes, and for his thesis project, he set about to reducing them. Instead of having them reduced by individuals sitting at a plate-measuring machine, they were automatically reduced by a new, state-of-the-art plate-measuring machine produced by the U.S. Naval Observatory.  Of equal importance, the data was reduced the data with a different technique than that used before. His thesis adviser, Heinrich Eichhorn, was one of the fathers of analytical astrometry, and it was Eichhorn's technique that was invoked for the data analysis.

Their results on Barnard's Star were published in 1973, and they were bad news for van de Kamp -- some of the points in which they had the most confidence did not fit van de Kamp's curve. Without confrontation, they quietly stated that they had found no evidence whatsoever for Peter van de Kamp planet.  And it got worse -- that same year, another paper was published in the Astronomical Journal by John Hershey, who was also working at the Swarthmore College Observatory.

Hershey had studied another star called Gliese 793, another low-mass M dwarf star, and he found that, if he plotted the astrometric wobbles of Barnard's star and Gliese 793 together, both of them took a jump in one direction in 1949, and in 1957 took another jump in the other direction.  The implications of Heshey's data were devastating for van de Kamp's 'discovery': either both stars had exactly the same planet orbiting them, or else there were major systematic errors in the latter's observations.

It turned out that van de Kamp's observations were riddled with major systematic inaccuracies.  In 1949, there had been a major change in the telescope; they put in a new cast-iron cell to hold the Swarthmore College refracting lens. They also changed the photographic emulsions they were using, which made an enormous difference when measuring objects in size down to one one hundredth of the size of a star's blur.  In 1957, they made another change --a lens adjustment.

Astro-imaging of Barnard's Star.  Credit: Steve Quirk .

And so it was, that after a lifetime's work, much of it studying Barnard's Star, van de Kamp discarded forty years worth of data.  still continuing to believe that the star should possess a planet, he started anew with more observations.  However, by the autumn of 1973 following his discredited observations, most astronomers were no longer prepared to give his work much credence and the field of exoplanet research fell into a deep sleep for two decades.

Roll the clock forward 22 years and on October 6, 1995, Michel Mayor and Didier Queloz announced the verified discovery of the first genuine exoplanet, orbiting a Sun-like star located 50.9 light years (15.6 parsecs) away in the constellation of Pegasus. The discovery, via the radial velocity method of 'Belleraphon' (as the planet became known), orbiting 51 Pegasi was made in France at the Observatoire de Haute-Provence, using the ELODIE spectrograph.

It turned out that this planet from hell was a gas giant, approximately half the mass of Jupiter, but with an orbital period of just over four days -- a fraction of that of Mercury around our star.  In the intervening years, a host of such 'Hot Jupiters' have been discovered, and they're unlike anything in our solar system.  They're located so close to their stars that they have atmospheric temperatures nearing 1,000 degrees Celsius, they're tidally locked to their stars, and hence must turbulence and winds to dwarf anything in our solar system. The smart money is placed on a theory that suggests that such planets have migrated from original positions in their solar systems similar to that of our own Jupiter.

And what of Barnard's Star?  NASA's Hubble Space Telescope (HST) fine-guidance sensor team, led by Fritz Benedict, of the University of Texas, has been following the star to ascertain whether it has planetary companions, but has so far drawn a blank.  Instead, Barnard's star is more useful for debugging mechanical problems on the HST, because when Barnard's star seems to wobble, it usually means that there something wrong with the space telescope!

For now though, the jury's still out on whether our very closest stellar neighbours possess earth mass planets. Astronomers are fairly certain that these stars do not possess gas giants and speculate that earth-mass planets may be orbiting any of the stars in the Alpha Centauri triple star system for example.  The habitable zones of these stars lie at a distance similar to that of our Sun's, and are close enough to the stars to ensure gravity from their stellar companions would not eject terrestrial-sized rocky worlds from the triple system.  There may indeed, even be Earth-mass planets orbiting Barnard's Star.  And a final resolution to these questions won't be long in coming either -- a Planetary Society project is underway called FINDS Exo-Earths (an acronym for Fibre-optic Improved Next generation Doppler Search for Exo-Earths).

This new high-end optical system has been installed on the 3-metre telescope at the Lick Observatory, dramatically increasing discoveries of smaller exoplanets and playing a crucial role in verifying Earth-sized planet candidates from the Kepler planet-hunter mission.

Peter van de Kamp believed in another world orbiting Barnard's Star, but his observations and data were not repeatable or verifiable -- a situation that ultimately is not worth much in science.  Ultimately, with the relatively primitive technology of the early twentieth century he believed too much.

Ironically however, the next generation of telescopes may yet prove his beliefs to be correct.

Stellarium: A Star amongst Planetarium Software

Stellarium's astronomical object search facility.

The COMPUTER EXPERT reviews a piece of versatile and capable planetarium software.

Many people with 3G mobile phones and portable media devices such as Apple’s iPod have been amazed at the quality of my applications, especially those relating to astronomy and navigating your way around the night sky.  Most of my colleagues who are not amateur astronomers have hours of fun with planetarium ‘apps’ for their devices.

However, the software for computers pre-dates that for mobile devices by years and it is much more substantial, effective and interesting.  The astronomy planetarium software genre for use by the general public dates back to the early 1990s with the release of ground-breaking programs such as Redshift.  Excellent though such early software was, the applications available were limited by the technology of the era, and pale into insignificance by the plethora of quality and substantial applications available today.

When it comes to planetarium software for both the PC and the Apple Mac there’s a huge choice of capable programmes on offer including Imaginova’s Starry Night in its various, United Soft Media’s Redshift (now up to version 7), Sky X, SkyMap and Cartes du Ciel (Star Charts).  The bad news is that although these products come complete with bells and whistles and are used by amateur and professional astronomers alike, they’re not free, and in their various editions can cost anything from £30 up to £200.  In addition these heavyweights have high hardware requirements Starry Night in its professional editions requires at least 2GB RAM and a fast dual core processor.  It also claims a massive slice of valuable hard drive space.

As usual, the internet comes up trumps yet again with a highly capable free alternative, Stellarium.  It is used in professional planetariums worldwide and is GPL desktop software which renders realistic skies in real time with openGL graphics software. The software allows you to see what you can observe with the naked eyes, binoculars or a small telescope.

Downloading Stellarium from its website at stellarium.org is a breeze.   The program is available for all main formats i.e. Windows PC, Mac or Linux.  At just 43MB for the Windows version the program downloads in thirty seconds on a broadband connection, and the easy installation will be complete on even the slowest machines within a few minutes.

Stellarium displays the astronomical target, in this case Saturn in its real time position against the background stars.

The program executes in seconds and you’re initially greeted by the opening location scene.  At this point it is probably advisable to click the location icon and enter the name of your town or city or grid reference.  Remember that this is real time software, and to hide daylight simply toggle the atmosphere icon.  And without any more ado, your cosmic voyage begins.  Just open the search box and type in Saturn (the available predictive text will help), for example.  Initially Stellarium will show you a naked eye view and will show you exactly where in the night sky outside the planet will be.  To put place it in its proper position within the constellations you can toggle constellation art, labels and boundaries. If the object is below the horizon and is not available from your viewing location Stellarium includes a toggle icon to remove the ground and horizon.  At the present time Saturn is in the constellation Virgo and is just visible in mid-northern latitudes after sunset, quite low down on the western horizon.

Once found it’s just a simple task of going out into your backyard and using the accurate depiction of Saturn in the night sky in Stellarium to find it in the identical-looking real thing above your head.  Of course if you’ve got optical aids you’ll want to observe Saturn with your binoculars (a yellowish disk) or through a small telescope (a beautiful ringed planet with cloud bands, rings and an entourage of moons).  Of course, you will have already seen Saturn at much more close quarters; Stellarium allows you to zoom in on an object either by the backslash key on your keyboard or via your mouse.  Many of the beautiful images of nebulae, galaxies and planets originate from NASA and further downloads are available after the initial program installation; these include more stars and more and fainter deep sky objects.

Zooming in on the target.  Maximum magnification regarding Saturn reveals this truly beautiful view: the planet respendent with cloud bands on the disk, its rings (including the Cassini Division, and of course its entourage of moons including Enceladus, Mimas,Tethys and Dione.  This is considerably better than the view through my 200mm Newtonian reflector.

The present version of the program is 0.10.6, and its capability if it was commercial software would be amazing enough; it’s incredible when you remember its freeware.  It possesses a default catalogue of over 600,000 stars, extra downloadable catalogues with more than 210 million stars; asterisms and illustrations of the constellations; constellations for twelve different cultures; images of nebulae (full Messier catalogue);realistic Milky Way; very realistic atmosphere, sunrise and sunset and the planets and their satellites

Its user interface include a powerful zoom, time control, multilingual capability , fisheye projection for planetarium domes, spherical mirror projection for your own low-cost dome, an all new graphical interface and extensive keyboard control and telescope control by which Stellarium and your computer will give a suitably adapted computer ‘go to’ capability.

In terms of visualisation, Stellarium offers equatorial and azimuth grids, star twinkling, shooting stars, eclipse simulation, skinnable landscapes, and now possesses spherical panorama projection.  The program can be customised with a plug-in system adding artificial satellites in real time, ocular simulation, telescope configuration and the ability to add new solar system objects from online resources.  You can add your own deep sky objects, landscapes, constellation images and scripts.

I really can’t recommend this freeware enough.  It is up there with professional commercial packages such as Starry Night, but has the added bonus of being tightly coded, small and unlike such commercial packages it can be considered in no way ‘bloatware’ and has been produced in the best programming traditions.  It is constantly updated by a group of academics, professional astronomers and the European Southern Observatory, and access to the internet allows for a database of astronomical objects to keep even the professional astronomer busy for years.  And free really does mean free, both Stellarium’s website and the program itself are devoid of any adware.

In summation then, a fantastic package that anyone with even a passing interest in the night sky should download straight away.  The only criticism I can possibly level at the software is that it is so detailed, so visually real that using it to explore the night sky may prevent you from venturing into your backyard with all the light pollution, freezing temperatures in winter, cloudy skies and dew on your telescope’s mirrors and eyepieces.

Andromeda Child’s Overall Verdict: ¬¬¬¬¬ (out of 5)

Pros: Free, comprehensive, capable better than much commercial software, tightly coded with limited hard disk space required.

Cons: So good, it may prevent you from observing the real night sky!

Website and download page: stellarium.org

Backyard Astronomical Sketching

    

My first attempt at astronomical sketching. The target is M82, the Cigar Galaxy in the constellation Ursa Major (the Great Bear) as recorded on March 4, 2010.  The realistic reverse out of my original sketching (right) was achieved on my computer by scanning in the original sketch and using Adobe Photoshop or the excellent free Artweaver Basic package and using the negative feature available in both pieces of software. 

Starting out in astronomy and want some astro-images to impress your friends but you don't have a DSLR camera or CCD?  ANDY FLEMING discusses a more traditional, much cheaper and more educational method of recording one's view of celestial objects.  All you need is a pencil and some paper for backyard astronomical sketching!

It seems to be a natural progression....you commence with naked eye observing, then move on to binoculars, then visual observations with a telescope, and finally you progress to sketching.  For many years I was perfectly content to just assemble my telescope in the back garden and enjoy a tour of objects of interest in the night sky.  It was just plain, simple, relaxing, no strings attached observing.

However, there comes a point where you wish to show your friends and record for posterity your views of the night sky.  You take a look in any of the monthly astronomy magazines such as Sky and Telescope, Astronomy, or Astronomy and you are over-awed at the astronomical imaging produced by regular contributors such as Martin Mobberley ,Damian Peach or Keith Johnson using Digital Single-Lens Reflex (DSLR) cameras and motorised tripods or Charge Coupled Devices (CCD chips).  After a slight touch of envy, reality strikes following a request for photographic equipment to the domestic authorities (the missus): the answer is a resounding 'no'!  Put simply you simply don't have the money to replace your Dobsonian reflector with a refractor and CCD combination or to purchase a high quality DSLR camera costing over £400.  There's a recession on and the country is virtually bankrupt!

There is an altogether cheaper, traditional and more educational method that simultaneous to pushing your limits in artistry educates and familiarise you with your chosen areas of the night sky.  I'm talking about astronomical sketching, of course.

Let me state from the outset that I’m no artist... I tend to draw along straight lines!  However, I hope you enjoy my sketches, and that they inspire you to try sketching yourself.  In addition to having something to show for your observing session, drawing the objects requires far greater attention to the detail in the view through the eyepiece.  Another benefit is that you are far more likely to recognise the object in future observation sessions, as what you see through the eyepiece is, of course, frequently very different to images in photographs.

Sketching takes some getting used to at first - it isn’t easy learning to manage a telescope, star charts, clipboard, paper, pencil and dim red light torch!  But if I can do it anyone can!  It takes some practice to combine the use of a pencil for shading and eraser for providing the familiar smudges of galaxies and nebulae.  Don't forget that although an ordinary HB pencil will do, a collection that includes softer B, 2B or 4B pencils will produce far better results.

M57 the Ring Nebula in Lyra recorded on October 27 2008.

Beginning with some distinct and easy objects, depending on what’s visible, such as the Cigar Galaxy, the Orion Nebula, and the Ring Nebula is a good idea.  Also remember that you don’t have to spend you entire observing session sketching – make sure you leave plenty of time just for relaxing star gazing!

Completed Deep Sky Report Form including a sketch of galaxy M81 (Bode's Nebula) in Ursa Major (the Great Bear) as recorded on March 4, 2010.

If you're interested in practising the art of astronomical sketching, I thoroughly recommend Darren Bushnall's book Observing the Deep Sky (Crowood Press Ltd., 2005). This invaluable publication includes a Deep Sky Report specimen form that can be used as the basis for your recordings.  Such a standard form can be scanned in to, or reproduced using desk top publishing software on your computer and printed out for sketching sessions.  As shown in my sketches the form includes a circle for the telescope’s field of view and labels and fields for such things as object name, Messier Number, attributes of equipment used, date and time of the observation etc.  This ensures that your observing drawings are fully labelled, and in future, when you use different equipment or are observing at a different location, you can account for the differences in your observations.

Ultimately, the effort is well worthwhile – you will have learned far more about the objects you observe, plus you will have the satisfaction of showing your drawings to family members, friends or members of the society.  Why not scan them into your computer and make negatives of your sketches, so the monochrome drawings are no longer reversed out?  You can then publish them on your website or Facebook profile for all to see!

Now then, I must talk to the wife about an artist’s pencil set!!!

Real Astronomy Under Velvet Black Skies

ANDY FLEMING reminisces about his first experience of astronomical observing with a telescope at a dark sky location deep inside the North Yorkshire Moors National Park.

It is one of life’s subtle ironies that thanks to our industry and high technology that in other ways brings so many benefits to our everyday lives, one of the greatest of all natural wonders, has been lost to the majority of our country’s population. We’re talking, of course about a velvet-black night sky dotted with countless stars, nebulae, and galaxies.  Truth be told, it is not our technology that denies us this most beautiful of natural spectacles, but our shameful and profligate waste of our natural resources and energy. Namely, of course, it is light pollution, coupled with industrial pollutants, vehicle emissions and particulates. It is a severe problem where I live in the UK's Tees Valley, where industry at Teesmouth illuminates our horizons with the glare of a thousand artificial sodium vapour suns.
If you’re lucky, and located in a dark, secluded corner of such a conurbation, you can just about succeed with the “Ursa Minor test” and pick out all of the stars in that constellation down to Magnitude 5 with the naked eye (albeit with averted vision). We won’t be unduly negative about such abodes however – there are still wonders aplenty to be seen from back gardens including double stars, the planets, galaxies and planetary nebulae, and of course the stunning and lovely Great Nebula in the Sword of Orion. But they are washed out, shadows of themselves even through a telescope, reminiscent of a television set with the contrast dramatically reduced. They are awe-inspiring, but we have doubtless been robbed of much of the awe.

Spiral galaxies M81 (also known as NGC 3031 or Bode's Galaxy), and M82/NGC 3034, the edge-on Cigar Galaxy.

An initial tour of the gorgeous black skies of a location such as the North Yorkshire Moors National Park, or any dark site therefore creates a soaring sense of wonder and awe – an uplifting surge of sheer excitement that will never be forgotten. Of course, an enjoyable tour of anything requires a good and learned tour guide with a well-planned itinerary, and in this respect my 12 year old son David and myself were lucky enough to share our first dark sky observing session with a fellow member of the Cleveland and Darlington Astronomical Society (CaDAS) Rob Peeling - in late October 2008.
Our rendezvous with Rob was to be Snilesworth Moor, close to Osmotherly, in the UK's North Yorkshire Moors National Park, just off the A19 trunk road, where the ancient Drover’s road south to Sutton Bank parts company with the metalled road to Ryedale and Helmsley.  Sure enough, Rob was already at our destination at the appointed meeting time of 8.00pm. We were beneath the mighty Black Hambleton Moor, Rob’s superb12” Dobsonian already in position and online to the heavens. We had chosen the coldest night so far that autumn for our tour of the local Cosmos – a chilling minus three degrees according to the car’s external thermometer. Of course, it was so cold precisely because the sky was totally cloudless, and the seeing exceptional.

M57/NGC6720 The Ring Nebula in Lyra.

We shook hands with Rob, and within seconds, as our eyes started to adapt to the pitch blackness, untold celestial wonders aplenty started to encroach on our naked eye view. The total blackness was punctuated only by very distant lights in the northern part of the Vale of York, and a couple of red aircraft warning beacons on the Bilsdale West Moor television tower, one of the most exposed structures in the land, and about eight miles distant to the north east.  As we looked skywards with our naked eyes, just as promised in countless astronomy textbooks, was the stupendously stunning Milky Way, our home galaxy, it’s disk full of a myriad of stars traversing their way east-west right through the hearts of the constellations of Lacerta, Cygnus, Perseus and Cassiopeia.  Would we be able to see the furthest the unaided human eye can see on a clear night?  Could we really see two million light years to the Andromeda Galaxy (M31) with our eyes alone? And if so would it be spectacular? At home, it’s so easy (due to other stars being bleached out by light pollution) to find our old friend, the orange/yellow Magnitude 2 guide star Mirach (beta Andromedae), we first used to track down M31 a couple of years ago with binoculars. But under these superb skies there were just so many stars that Mirach was lost.

M33/NGC598, the Triangulum Galaxy.

However, once beta Andromedae was found, amazingly, we didn’t need mu and nu Andromedae , because intrusively visible above Mirach, and offset to the right a little was an elongated smudge of beautiful pale light, perhaps half a degree or more in diameter. Here was M31, not a point, but the central bulge of our sister spiral galaxy, amazingly seen looking like a galaxy, with the naked eye.If this wasn’t enough, even more unbelievably, virtually equidistant below and slightly to the left of beta Andromedae near alpha Triangulum was another much fainter smudge. With goosebumps and a lump in our throats, and a quick confirmation from Rob, we realised that remarkably we were viewing the diffuse Triangulum Galaxy (M33/NGC598). We hurriedly looked at these two magnificent galaxies through binoculars – M31 being elongated by well over the width of a couple of degrees and M33, virtually face on looking absolutely stunning.

It was time to assemble our telescope, an 8.5 inch f4.5 Newtonian reflector. Our equipment also included a 9mm Orthoscopic eyepiece, a 28mm Plossl and a x2 Barlow, which combined give a decent portfolio of viewing. As previous to this amazing night out in the National Park, we had been graced with several reasonably clear evenings, and as this wonderful telescope had seen frequent use at home, I was concerned that wind-blown dirt and particulates had entered the instrument and been deposited on the primary mirror from our trusty Silver Birch, and Apple Tree at the rear of our garden. Indeed there was considerable dirt on the mirror, and to rectify this problem I had painstakingly removed and cleaned the mirror with de-ionised water and cotton wool. We would soon discover that this work, subsequent re-collimation and eyepiece cleaning had paid dividends.

M27/NGC6853, the Dumbbell Nebula.

We first visited a couple of stunning planetary nebulae - the Dumbbell (M27) that we had so proudly found at home after Rob’s clear and concise instructions. Then it was off to the Ring Nebula in Lyra (M57), and the Blue Snowball. We took a peek at the beautiful double star Albireo in Cygnus – wonderfully resolved into its striking blue and yellow constituents.  Next, Rob set us a challenge, using his instructions, we were to locate successfully the faint Ghost of Mirach Galaxy. Our next port-of-call was the beautiful face-on spiral galaxy M33 in Triangulum that we had earlier seen with our unaided eyes and then our binoculars. Its beautiful spiral structure was well apparent – so too were it’s bring star forming regions in its outer spiral arms. Not too far away we viewed M110/NGC205 – one of M31’s satellite galaxies.

Next it was off to Bode’s Nebulae, incorrect nomenclature of course – they are the beautiful Magnitude 6.9 spiral galaxy M81/NGC3031 and of course the Magnitude 8.4 virtually edge on “Cigar Galaxy” M82/NGC3034. These two gems are relatively easy to locate, even though they were fairly low down in the north by star-hopping using Dubhe (alpha Ursa Majoris) and Polaris, and then from Rob’s “The Cheese” asterism of three stars slightly to the left and down from these galaxies in your field of view.

It was time for a personal detour to the lovely Double Cluster NGC869 in Perseus, visible from our location with the unaided eye, beautiful through binoculars and jaw-dropping through our telescope. A myriad of stars to inebriate one’s retina.  Other splendours we observed included Globular Clusters M15/NGC7078,M103/NGC581 near Ruchbah in Cassiopeia, the Crab Nebula (M1/NGC1952) the remnant of the supernova witnessed by ancient Chinese astronomers in1054AD, and easy to locate in a dark sky near zeta Tauri. As we observed it’s structure one thought about the rapidly rotating tiny neutron star at its centre whose almost artificial atomic-clock-regular spinning jets of radiation were first discovered at Cambridge University in 1967 by Jocelyn Bell and labelled LGM (Little Green Men) on her print-out. It was, of course the first pulsar to be identified.

The constellation of Orion.  Visible in the Hunter's belt is M42, the Great Nebula star forming region.

As time passed we saw bloated red Betelgeuse and Meissa rise, followed by the whole enchilada of the winter constellation of Orion the Hunter, always reminding one of approaching Christmas. It was difficult to restrain our impatience at waiting to observe the beauty in the hunter’s sword, but of course, it was well worth the wait. The Great Nebula M42, was awesome, that huge reflection nebula of gas and dust reminding us all of how every star and planet, including the Sun, the Earth and indeed all living things, including ourselves for that matter, came to be. Indeed this whole area of the sky from Alnilam, Alnitak and Mintaka through to M42 and M43 is a wondrous sight to behold with nebulosity galore – hot, young stars, such as those in the Trapezium – illuminating and exciting the atoms, molecules and clouds of gas and dust from which they were born.

Veil Nebula NGC 6960/6979/6992/6995, Cygnus SNR, Cygnus Loop

We saw many more objects that wonderful evening, but for brevity’s sake I will end on an even higher note for ourselves – three objects that had previously eluded us at our stage of observing, but to which we were effectively guided by Rob. Firstly, the beautifully intricate filaments of the supernova remnant, the Veil Nebula (NGC 6960). Bearing witness to the final collapse and obliteration of a massive star, far larger than our Sun, this beautiful stellar death shroud bears witness to the fact that out of one of the Cosmos’s most destructive events outstanding beauty arises. Of course, much more than visual beauty has been created. The progenitor star of NGC 6960 expelled into the Cosmos the ingredients to make new stars when it detonated. It also expelled heavier elements that one day, millions of years from now will create planets and rocky worlds, and possibly sentient beings, who like us have imagination, intelligence and consciousness and who can observe and endeavour to understand the Cosmos from which they were made.
Our last two targets were very much in our nearby cosmic vicinity – the two mighty gas giant worlds of Uranus and Neptune. Under such conditions, and with a superb guide, Uranus was an easy target to find, it’s beautiful blue/green orb being an easy giveaway. Blue Neptune with its oceans of methane and hydrogen was considerably more difficult to find due to it’s low declination in the south west as it was not long from setting. Rob made a considerable attempt to find the large satellite of this last outpost of the Sun’s entourage of planets, the pink-snow covered Triton, but to no avail. Hardly a disappointment considering the plethora of other wonders we enjoyed that evening, which also included several meteors emanating from their radiant in Taurus.

At 11pm, despite multiple layers of clothing, but with the thermometer still falling and it becoming intensely cold, it was with heavy hearts that we disassembled our telescopes and headed back to Teesside.  In conclusion, in all of our serious observing it was our best ever evening under the stars.

To those readers who have never experienced a truly dark sky, and who are sceptical of the difference it makes to observing the heavens, forget a day out, treat yourself to a night out with the stars instead. With naked eyes, binoculars, or a telescope, literally – there’s nothing on the Earth that can beat it!!!

Hubble - The People's Telescope: The Best May Still Be To Come

By ANDY FLEMING

The Hubble Space Telescope (Credit: NASA)

Named after the astronomer Edwin Hubble, the Hubble Space Telescope was launched in April 1990. It was the first space telescope designed to be serviced in space, which is lucky, all things considered.  Its existence is due in no small part to renowned Princeton astrophysicist Lyman Spitzer (after whom another NASA Great Observatory Telescope is named) who tirelessly lobbied NASA from the 1960s onwards to launch a space telescope.

Initially jubilant, astronomers were soon horrified to discover that Hubble's 2.4-metre main mirror had been ground to the wrong shape. Although it was only off by 2.2 micrometres, this badly blurred the telescope's vision and made the scientists who had promised the world new images and science in exchange for $1.5 billion of public money the butt of jokes. The fiasco, inevitably dubbed "Hubble Trouble" by the press, wasn't helped when even the limited science the crippled Hubble could do was threatened as its gyroscopes, needed to control the orientation of the telescope, started to fail one by one.

By 1993, as NASA prepared to launch a rescue mission, the situation looked bleak. The telescope "probably wouldn't have gone on for more than a year or two" without repairs, says John Grunsfeld, an astronaut who flew on the most recent Hubble servicing mission. Happily, the rescue mission was a success. Shuttle astronauts installed new instruments that corrected for the flawed mirror, and replaced the gyroscopes.

Two years later, Hubble gave us the deepest ever view of the universe, peering back to an era just 1 billion years after the big bang to see the primordial building blocks that aggregated to form galaxies like our own.

The success of the 1993 servicing mission encouraged NASA to mount three more (in 1997, 1999 and 2002). Far from merely keeping the observatory alive, astronauts installed updated instruments on these missions that dramatically improved Hubble's power. It was "as if you took in your Chevy Nova [for repairs] and they gave you back a Lear jet," says Steven Beckwith, who from 1998 to 2005 headed the Space Telescope Science Institute (STScI) in Baltimore, Maryland, where Hubble's observations are planned.

Along the way, in 1998, Hubble's measurements of supernovas in distant galaxies unexpectedly revealed that the universe is expanding at an ever-increasing pace, propelled by a mysterious entity now known as dark energy. In 2001 the space observatory also managed to make the first measurement of a chemical in the atmosphere of a planet in an alien solar system.

Despite its successes, Hubble's life looked like it would be cut short when in 2004, NASA's then administrator Sean O'Keefe announced the agency would send no more servicing missions to Hubble, citing unacceptable risks to astronauts in the wake of the Columbia shuttle disaster of 2003, in which the craft exploded on re-entry, killing its crew.

By this time, three of Hubble's gyroscopes were already broken or ailing and no one was sure how long the other three would last. The public had fallen in love with Hubble and its magnificent images, and citizen petitions and an outcry among astronomers put pressure on NASA, and after a high-level panel of experts declared that another mission to Hubble would not be exceptionally risky, the agency reversed course, leading to the most recent servicing mission, in May 2009.

No more are planned. The remainder of the shuttle fleet that astronauts used to reach Hubble is scheduled to retire by the year's end. And in 2014, NASA plans to launch Hubble's successor, an infrared observatory called the James Webb Space Telescope, which will probe galaxies even further away and make more measurements of exoplanet atmospheres.

According to Grunsfeld, now STScI's deputy director, plans are afoot for a robotic mission to grab Hubble when it reaches the end of its useful life, nudging it into Earth's atmosphere where most of it would be incinerated. Only the mirror is sturdy enough to survive the fall into an empty patch of ocean.

But let's not get ahead of ourselves - Hubble is far from finished. The instruments installed in May 2009, including the Wide Field Camera 3, which took the adjacent image of the Butterfly nebula, 3,800 light years away, have boosted its powers yet again. It might have as much as a decade of life left even without more servicing. "It really is only reaching its full stride now, after 20 years," says Grunsfeld.

The Hubble telescope is really only now reaching its full stride, after 20 years, and a key priority for Hubble will be to explore the origin of dark energy by probing for it at earlier times in the universe's history. Hubble scientist Malcolm Niedner of NASA's Goddard Space Flight Center in Greenbelt, Maryland, is not willing to bet on what its most important discovery will be. "More than half of the most amazing textbook-changing science to emerge from this telescope occurred in areas we couldn't even have dreamed of," he says. "Expect the unexpected.

Take a Fantastic Cosmic Voyage!

ANDY FLEMING reviews a superb short documentary that takes the viewer on a journey across the visible Universe, and in the process effectively portrays our true place within it.

Cosmic Voyage is one of a series of "powers of ten" short documentary films, that portray our true place in the Cosmos.  It is similar in format to the National Film Board of Canada's Cosmic Zoom, and IBM's classic Powers of Ten educational video.

Morgan Freeman, narrator of IMAX Cosmic Voyage

Cosmic Voyage was made in 1996 in the IMAX format, and is my favourite film of the genre and format.  The background music is inspiring, as is, of course, the narrator award-winning actor Morgan Freeman. The film was presented by the Smithsonian Institution's National Air and Space Museum, and played in IMAX theatres worldwide.

Cosmic Voyage takes the viewer on a fabulous journey through forty-two orders of magnitude, beginning with a celebration in Italy right to the edge of the observable universe! The view zooms back down to the Earth, homing in upon a raindrop on a leaf.  Further magnification takes the viewer right down to sub-atomic particles ending in the constituents of protons and neutrons... quarks.

In addition, the film offers a brief insight into the Big Bang Theory, black holes, and the development of our Solar System. It also simulates a journey through Fermi lab’s Tevatron particle accelerator in Chicago, where an atom collision is depicted.

Cosmic Voyage was nominated for a 1997 Oscar Award under the category of Best Documentary Short Subject. Here's the first part of the film... watch it and you'll see why it’s just so inspirational!


Director: Bayley Silleck

Writers: Michael Miner, Bayley Silleck
Narrator: Morgan Freeman

Cosmic Voyage is available on DVD from Amazon:

Saturn: Lord of the Rings, Lord of the Skies

NASA's robot spacecraft Voyager 2 made this image of Saturn as it began to explore the Saturn system in 1981. Saturn's famous rings are visible along with two of its moons, Rhea and Dione which appear as faint dots on the right and lower right part of the picture. Astronomers believe that Saturn's moons play a fundamental role in sculpting its elaborate ring system.  (Credit: NASA, Voyager 2).

ANDY FLEMING takes a look through his telescope at his favourite night sky object, our solar system's beautiful ringed gas giant planet Saturn and its entourage of moons.

If there is one celestial object that is both readily visible in even the worst light polluted skies, and yet full of the astronomical “wow” factor, it has to be Saturn, our solar system’s beautiful ringed gas giant planet.  For anyone new to telescopic observing, Saturn is usually an early and easy target. The planet has fascinated me for a long time, revealing an interesting bright disk when viewed through my 10x50 binoculars, but definite tantalising “handles” or “ears” when viewed with some old 12x50s - very much in accordance with Galileo’s findings in the early seventeenth century. It yearns for greater magnification…

The window to obtain a stunning view of this gaseous behemoth and its rings is with us now, and it will be well worth making an effort,while it graces our skies in the constellations of Virgo. Indeed, at present it is very easy to find, even by the naked eye, being the brightest object visible between those constellations at apparent magnitude 1.1, and it ring system is well visbible.  Saturn is like an old friend to me, both often gracing our skies and never failing to impress when other planets, like Mars, often fail.

When I first saw Saturn through by 200mm f4.5 Newtonian Reflector, I was unprepared for the awesome views of the planet as revealed through a large, quality telescope with a sturdy mount.  Through a 26mm Plossl eyepiece, the planet is small, very bright, with clearly visible rings, and at least one of its family of moons is visible (Titan, of course). Using the x2 Barlow and Plossl, the whole system becomes much more striking, with another couple of specks of moons coming into view (Rhea, the planet’s second largest and Tethys). Saturn has a family of nearly sixty moons in tow, and to really enjoy this “mini solar system” a 9mm eyepiece gives a great view, the Cassini Division and the A and B rings coming clearly into view. Close inspection of the planet itself shows a slight shadow on the disc, cast by its beautiful ring system. There are a few cloud bandings visible on the planet’s disc – these bands however, are much less pronounced than those of Jupiter.

It is truly amazing to think, as you view the solar system’s second largest plane, that it is a staggering 1.3 billion kilometers away – indeed the light reaching your eyes from Saturn has taken over an hour and a half to reach Earth. It kind of gives you some idea of astronomical distances, as in cosmic terms, Saturn isn’t even next door – it’s in another room in our house!

    

Returning to its moons, the largest, Titan has already been visited by a robotic emissary from Earth, in the form of the ESA Huygens lander, which along with NASA’s Cassini spacecraft has revealed an amazing world of orange skies, ice rock, mountains and possible liquid ethane lakes, that starting with the great Carl Sagan has fascinated astronomers for years. This enigmatic tiny little world appears to have a definite brownish hue through the telescope using the Barlow and my 9mm orthoscopic eyepiece, due to its bizarre hydrocarbon atmosphere. Indeed, it is the only moon in the Solar system with an atmosphere (one and a half times as dense as that of the Earth) – a pre-biotic atmosphere of tholins in icy stasis – an almost Earth-like atmosphere, frozen in time before life got going.  Titan has weather too – it rains liquid ethane and methane on Titan – yes it’s that cold!

Based on data from the Cassini spacecraft, researchers are now arguing that liquid water reservoirs exist only tens of metres below the surface of Saturn's small but active moon Enceladus. The exciting results centre around towering jets and plumes of material erupting from the moon's surface. The plumes originate in the long tiger stripe fractures of the south polar region pictured here. Clearly an important step in the search for water and the potential for the origin of life beyond planet Earth, such near-surface reservoirs of water would be far more accessible than, for example, the internal ocean detected on the Jovian moon Europa.

Observing Titan, you envisage those boulders and rocks of solid ice from the Huygens photographs, and you think about Cassini’s scans of this tiny world. You suddenly realise Titan is not just a small disk in your telescope - it’s a place -we’ve been to Titan!  The air is starting to chill, but before I pack away the equipment, I observe other minute specks of light around Saturn. Averted vision shows them to be even brighter – they are more of Saturn’s family of moons, including Rhea and Tethys again, and Dione and possibly even Enceladus! I think of venting water and ice inhaled by Cassini, and I wonder how liquid water possibly exists within such a deep freeze as the Saturnian system. I think of Cassini’sevidence for a deep subsurface water ocean on Titan, kept liquid by the immense gravitational tidal forces of Saturn. And I think how the Lord of the Rings has wonders aplenty to keep mankind fascinated for decades and centuries to come…

Images of Saturn's largest moon, Titan. Left: From the mankind's most distant, controlled spacecraft landing comes a colour photograph of the rock-strewn surface of the moon (courtesy NASA/ESA/Cassini-Huygens). Right: An artist's concept shows a mirror-smooth lake of ethane on the surface of the smoggy moon. (courtesy NASA)