Fairvale Observatory Part-3, Progress: modded DSLR, computer control, autoguiding etc.

April 4, 2016 by grahamrob in Autoguiding, Equipment, General Astronomy, Imaging, Software and tagged DSO Imaging, Photography | 4 Comments

It’s been a while since I last took a look at developments here at Fairvale Observatory (Part-1 & Part-2) and looking back it’s pleasing to see that progress has continued with positive results. After acquiring the William Optics GT81 refractor and AZ-EQ6 mount in 2014 I have been experimenting and enjoying the equipment’s significant abilities until recently but have now embarked on some new, potentially important improvements that hopefully will result in significant breakthroughs.

At the start perhaps the biggest problem for imaging was polar alignment, made very difficult here as my house almost completely obscures Polaris. It took some time but I’ve now overcome this by using the Synscan handset polar alignment technique, which now enables me to achieve an accuracy of just a few arc-seconds and has led to a significant increase in imaging times of at least 180 seconds.

With the short focal length of the fast William Optics this level of alignment error works well and I’ve been pleased to obtain decent images of larger DSO features such as the Great Orion, Rosette and Veil nebulae i.e. near / middle distance objects, ideally at least 1^o in size with an apparent magnitude of +7 or better. Once I’ve exhausted all these targets, and I have fortunately been discovering more and more, it’ll be time for another telescope!

The small things matter too and in this regard I’ve added a number of useful items:

Made a solar filter and finder tube for the WO GT81;
At last, I recently collected the cables together into two looms;
Purchased a 12mm reticle to aid alignment;
Astronomik CLS light pollution clip filter;
Photoshop – an old version but I’ve been successfully using it for processing.

The set-up has become a lot tidier and logistics made easier by collecting the power and camera cables into two separate looms (camera loom not shown) and permanently attaching the HiTec Astro control cable to the mount – why didn’t I do this before?

More significant additions that I’ve already reviewed include a modded Canon 550D DSLR, which together with improved tracking has revolutionised imaging and a recently a Vixen Polarie, that has transformed widefield photography and added a new dimension – transportability. It’s early days and I have not really got to grips with the Vixen Polarie yet but initial use suggests it’s going to be a very useful addition and potential game changer.

At the end of last year in Reflections I outlined my goals for 2016 and I am pleased to say that I have at last just started to establish the equipment and software to start autoguiding, the holy grail of astroimaging that when fully working should enable me to achieve exposure times significantly greater than present – which is likely to be at least another couple of months. For a while I have been successfully using EQMOD /ASCOM combined with Cartes du Ciel for tracking. There were some initial connection problems but now using a HiTec Astro EQDIR adapter and a better quality USB cable seems to have improved this matter; I’ve also recently secured it to the tripod making the set-up more stable and aiding logistics. I still polar align with Synscan before switching to EQMOD-Cartes du Ciel for additional star alignment, slewing and tracking.

Using EQMOD-Cartes du Ciel makes slewing to any chosen object much easier than Synscan but its use has introduced another operating problem. After slewing to a chosen object or star it is never exactly centred and some manual fine alignment is almost always necessary at this point. The problem is that this requires being at the eyepiece, which of course is not located by the computer, which means frequent toing and froing between the two locations and a lot of guesswork when adjusting the mount from the computer. In reality this is not very practical and I have therefore just purchased a gamepad that links wirelessly to the computer and allows mount adjustments to be made when at the eyepiece. It’s not quite set up yet but nearly and I’m impressed; ASCOM even allows you to add WAV files that speak to you when making changes – sounds like a gimmick but when in the dark with lots of items to attend to it is actually very useful and will hopefully reduce the possibility of making mistakes.

Wireless gamepad provides extensive control of critical alignment functions without being at the computer: front x4 buttons are assinged to set various slew rates, the mount-telescope can be directed either via the rear (shown right) joystick or POV buttons on the right, button-1 parks and button-2 syncs. Other buttons have yet to be allocated.

It had been my intention to use the ZWO ASI 120MC webcam for guiding, in fact I upgraded to this at the time of purchasing in 2014 for this very purpose as it has a specific port for ST4 autoguiding directly with the mount. However, very recently a Starlight Express Lodestar X2 guide camera came up second-hand and being widely acknowledged as one of the best guider cameras available I couldn’t resist! Of course, despite its pedigree like most things with astroimaging it has not been that simple to get working.

Starlight Express Lodestar x2 Guide Camera can be used either via the mount’s ST4 port or via ASCOM and the computer for pulse guiding – I’m doing the latter.

Despite being a dedicated guide camera with high operating specifications, at first I could not obtain any sort of image to prove it was even working but by transferring the lens from the ZWO camera and fiddling with the software I eventually got an image, phew! It’s important to say here that for guiding it is also necessary to use suitable guiding software and I‘m inevitably using PHD2, which itself is full of wonderful features and mischief that I am at the early stage of learning and trying out with the camera.

William Optics 50mm x 200mm with focus tube and Lodestar guide camera – after lengthy experimentation, insertion of a x2 Barlow barrel eventually achieved focus.

At this early stage the other inevitable obstacle has been achieving focus. The William Optics GT81 telescope conveniently comes with its own guidescope rings that elegantly form an integral part of the OTA shoe attachment. With guiding as a long term goal, I therefore obtained the matching 50mm William Optics guidescope at the time of purchasing the main telescope, which until now has been sitting in its box as I built up the courage to put it all together and attempt guiding.

The black art of autoguiding and infamous PHD2 screen; I have just for the first time got the camera and PHD2 working together: focussed, calibrated and guiding. The nature of the blue (RA) and red (DEC) traces indicates there’s still much to learn but at least it’s working and holds much promise for future imaging!

As a matching guidescope and a dedicated top-of-the-range guide camera I assumed it would all fit together and with a little adjustment focus could be obtained, right? Wrong. I played with the camera’s position but failed to get any idea where the point of focus was. Next time I initially had the same result but by now knew that the camera was working so persevered and by using the barrel from a x2 Barlow with the lens removed eventually found focus, about 2cm back from the maximum position achieved using just the guidescope + focus tube and camera. I know that there are many makes of equipment and permutations but surely a matched guidescope and standard, best-in-class guide camera should be designed to work together from the outset?

So what’s next? I am hoping that after a few more sessions with the guide scope and PHD2 I will able to start autoguiding properly. However, two years of astronomy and an early look at PHD2 tells me it probably won’t be that easy. Notwithstanding, two years of astronomy also tells me that perseverance is essential and usually pays off. Watch this space!

Nocturnal Safari

March 16, 2016 by grahamrob in Deep Sky Objects, General Astronomy and tagged Canis Major, Constellations, DSO Imaging, Monoceros, Nebulae, Orion | 3 Comments

night eyes

Asterisms of the night sky have long been the basis for astronomy, navigation, astrology, myths, general stories and even religion. Whilst over millennia their shapes inevitably change, on the scale of human life there is an element of permanence and certainty. With so many stars it is not difficult to ‘join-the-dots’ in order to arrive at a recognisable shape, thereby making identification easier. Simplest amongst these are the seasonal often geometric asterisms such as the Summer Triangle, Winter Hexagon and The Plough or Big Dipper. However, it is the 88 constellations that dominate our definition and description of the night sky.

Computer based planetarium usually trace the relevant shapes and often the underlying historical figures from which they were originally derived – though frankly in some cases these can be quite spurious and even misleading. Of the total constellations: 17 depict humans or mythological figures, 29 inanimate objects and a whopping 42 animals – the night sky might literally be described as something of a zoo!

Despite my cynicism the patterns can be very helpful when initially learning the night sky, as well as for navigating and descriptive purposes. When starting out in astronomy I deliberately did not purchase a GoTo mount in order to first better master the geography of the night’s celestial sphere. For this purpose I purchased a planisphere and to a degree (no pun intended) it did initially help but with so many stars, light pollution and the odd cloud it wasn’t always easy when it came to essential star identification and alignment. I am sure I will forever benefit from the effort but this is 2016 and inevitably I have succumbed to using Google Sky on my smartphone to identify or at least confirm a star’s identity. Equally inevitable, I now use an AZ-EQ6 GoTo mount, which when linked to the Cartes du Ciel planetarium software is a quick and powerful combination for locating and tracking objects.

As previously discussed, this winter has been unusually cloudy but I recently managed a rare though decent imaging session in which I was able to capture night animals of a different sort. Probably like most astronomers I find the mid-winter night sky to be the highlight of the year, making the aforementioned seeing problems all the more frustrating. I have already imaged various parts of everyone’s favourite, the Orion constellation and so this time was looking for alternative objects in a similar region that would be suitable for the William Optics GT81. Whilst I find many if not most of the star asterisms unconvincing, there’s no denying that some of the DSO shapes really do look like animals and this time I found two.

animal2

NGC 2174 or the Monkey Head Nebula is located within the Milky Way, between Orion’s club and Castor’s left foot. An HII emission nebula, with an apparent magnitude of +6.8 and 40’ apparent dimension, it was a good target and a very convincing monkey’s head. Closer inspection of the image shows another smaller HII nebula north above NGC 2174 called Sh2-247, that is not only connected to the monkey but they are both part of the even larger GEM OB-1 molecular cloud complex which covers a massive region of 570 x 770 light-years!

NGC 2174 & Sh2-247 nebula above. WO GT81 & modded Canon 550D + FF | 20 x 180 sec @ ISO 1,600 | 10th February 2016

NGC 2174 The Monkey Head Nebula, cropped & inverted

In addition, situated between the constellations of Canis Major and Monoceros is IC 2177 the Seagull Nebula, which is also within the Milky Way but ‘flying’ lower than the Monkey Head Nebula to the left (south-east) of the Orion. More than 2.5^o from wing to wing, a number of bright star clusters are associated with this emission nebula, notable of which is the ‘bird’s head’ designated NGC 2327; IC 2177 is also known as the Parrot’s Head Nebula, which given the form of NGC 2327 I’m inclined to prefer.

IC 2177 The Seagull Nebula. WO GT81 & modded Canon 550D + FF | 20 x 180 sec @ ISO 1,600 | 10th February 2016

I’ve previously imaged a number of other animal-like DSO objects: Jellyfish Nebula, Crab Nebula, Pelican Nebula and the famous Horsehead Nebula. Unlike the constellations they generally but not always, really do resemble the form their names imply. Now adding to this list the Monkey Head and Seagull (Parrot) Nebulae it sometimes seems like a safari rather than astronomy!

Sky Animalscrop

It’s all in the stars

February 24, 2016 by grahamrob in Deep Sky Objects, General Astronomy, Imaging, Universe and tagged Auriga, DSO Imaging, Hitchhiker's Guide to the Galaxy, Milky Way, Nebulae, Star Clusters | 2 Comments

After 24-weeks I have just completed Imagining Other Earths, a Coursera MOOC presented by David Spergel, Charles A. Young Professor of Astronomy at Princeton University – soon to become Director of the new Computational Centre of Astrophysics, NY – and cannot speak too highly of the course. In my quest to better understand what I am seeing and imaging, I have participated in five astronomy courses and this is by a country mile the best; how many country miles in a parsec I wonder? There was very little not covered about astronomy in the course, including related geology and life itself but it was outstanding for three reasons:

Frequent use of easy-to-understand equations to explain and link various processes responsible for the Universe and everything in it;
It is very comprehensive, thorough and well produced, and…
David’s lecturing is just very good – easy to understand and well delivered.

For some while now the trend in my astrophotography has been increasingly directed towards seeing the big picture and by coincidence the course followed a similar scientific theme in order to Imagine Other Earths throughout the Universe; a metaphor for life itself and possibilities across the Universe.

The ultimate question starts at the beginning – where do we come from? Moby and astrophysicists seem to have the answer: we are all made of stars. How we get from that to here may be an even bigger question and like the philosophers in The Hitchhikers Guide to the Galaxy looking for the meaning of life (answer = 42!), should keep many astrophysicists gainfully employed for aeons.

In the meantime there is strong evidence that we do indeed come from stars and their evolution through the process of nucleosynthesis, which is responsible for all but a few man-made elements that we find on Earth. Through the action of nuclear fusion a star burns its way through the periodic table, first from hydrogen to helium then carbon-oxygen-magnesium-silicon and eventually iron. Thereafter the other, heavier elements require even more extreme conditions – heat & pressure – that can only be found in the late or final stage of a star’s life such as a Super Nova.

When the Periodic Table was initially formulated in 1863 by Dimitri Mendeleev there were 53 elements, which through subsequent discovery have now grown to 118. I find it wonderful and exciting that almost all of these can be attributed to stellar evolution, which can be viewed and imaged in the night sky.

At this time of the year the Milky Way is a dominant feature passing across the winter night sky which provides numerous, sometimes spectacular objects that are favourable for imaging. Located close to the western edge of the Milky Way in the constellation of Auriga about 1,500 light-years from Earth, is IC 405 or Flaming Star Nebula and nearby (visually) IC 410 or Tadpole Nebula, itself at 12,000 light-years distance. Located across the central area between these objects is a star field, notable of which and actually within the IC 405 is the O-type blue variable star of AE Aurigae, that is responsible for illuminating the nebulae.

IC 405 is formed of two sections, consisting of an emission and reflection nebula. Radiation from the variable star AE Aurigea, that is located in the lower part of upper-east (left) lobe, excites the hydrogen gas of the nebula which then glows red, while carbon-rich dust also creates a blue reflection from the same star.

IC 405 (right)-The Flaming Star Nebula inc AE Aurigae varibale star & IC 405-The Tadpole Nebula: WO GT81 & modded Canon 550D + FF | 15 x 180 sec @ ISO 1,600 & full calibration | 8th December 2015

Located within the nebula IC 410 and partly responsible for its illumination is an open cluster of massive young stars, NGC 1893. Being just 4-million years old these bright star clusters are the site of new star formation and therefore are just starting their creation of new elements. The so named ‘tadpoles’ are filaments of cool gas and dust about 10 light-years long.

IC 410-The Tadpole Nebula: Illuminated from within by the NGC 1839 star cluster. Image cropped and forced to highlight the two ‘tadpoles’, which can just be seen indicated in the green ellipses (‘tails’ upwards)

Each nebula is large, respectively 30’ x 20’ and 40’ x 30’, with an apparent magnitude of +6.0, which combined with the star AE Aurigae makes an excellent target for the William Optics GT81. I find it thrilling to consider the processes taking place in these objects that I have captured in the photograph, which surely represents the ultimate Big Picture?

A Wider Perspective

January 23, 2016 by grahamrob in Deep Sky Objects, Equipment, General Astronomy, Widefield Imaging and tagged DSO Imaging, Nebulae, Orion, Photography | 3 Comments

I like to think and operate at both ends of the spectrum: sometimes considering detail and its implications and often exquisite beauty, whilst on the other hand taking a wider view will often provide broader insight and answers – notwithstanding, I am usually drawn towards the latter. There was no shortage of scope for such thoughts in my career as a geologist and now as my hobby in astronomy. I have become fascinated with parts of the Universe and captivated by imaging them: galaxies, nebulae, star cluster etc. but the wider view is often even more astounding and perplexing.

you-are-here-2

My nascent astroimaging has already produced some rewarding photographs, which using the fast William Optics GT81 refractor has enabled me to obtain images of up to 3^o FOV. In fact this became something of a theme last year, successfully imaging features such as the Sadr Region and as they say, one thing has led to another. Wanting to image even wider views there’s mostly only one alternative, using a camera and lens. I’ve tried this before, on a tripod and fixed to the ALT-AZ EQ6 mount but with mixed success. Meanwhile, I came across excellent pictures taken using lightweight tracking mounts on a tripod and as a result the way forwards became obvious; after scanning the Classified advertisements online for a while I was fortunate to find and purchase a second-hand Vixen Polarie mount last September.

Probably my favourite object, which can rightly be considered the signature image of the winter night sky and is therefore around at the moment, is the constellation of Orion and especially its numerous and often exciting constituent parts: M42, Horsehead & Flame Nebulae etc. After waiting for weeks for the clouds to clear, I briefly got a chance to image Orion using the Vixen Polarie early in November, whilst at the same time using the WO GT81 to obtain yet another picture of the irresistible Great Orion Nebula M42.

Orion’s Sword – including the wonderful Great Orion Nebula M42 et al : WO GT81 + modded Canon 550D & FF | 14 x 180 secs @ ISO 1,600 | 9th November 2015

The Vixen Polarie is a deceivingly simple and well-made solution to obtaining long exposure images of the wider night sky using a camera and lens. As stability remains essential for the mount and camera to operate at their best, I also purchased a decent Manfrotto tripod and suitable ball heads to attach the Polarie. After that it was simple, well not quite! Trying out the Polarie at the same time as using the GT81 and being first time out was a mistake. I fumbled setting up the equipment and initially even forgot to turn on the tracking, leaving only a short time to grab a few images before the clouds rolled in once again! Not surprisingly the results were mixed and I was left frustrated. With continuing poor seeing conditions, it was to be a further month before I had an opportunity to properly use the Vixen Polarie again – this time with a new Sigma 10 – 20 mm ultra-wide angle lens I had just purchased.

Vixen Polarie & Canon 700D + 18 – 55mm lens | 19 x 60 secs @ ISO 800 | 9th November 2015

Having by now spent more time looking at the manual (we all get there, in the end) and concentrating on imaging using only the Polarie, this time I was able to achieve a good set-up and remembered the correct sequence of operation. As the mount sits high on the tripod I am just about able to see Polaris in a small gap between the roof of my garage and house, something hitherto impossible when using the lower positioned AZ-EQ6 mount. As a result I am able to achieve a reasonably good visual polar alignment, though a polar scope made specifically for the Vixen Polarie would improve this further; probably something for another time? Nevertheless, such an alignment at Fairvale Observatory is a first and was a major breakthrough that has already permitted exposures of 4 minutes and could probably go to 5 to 6 minutes or more.

The high position of the Vixen Polarie on the tripod provides an otherwise elusive view of Polaris between the garage / utility room and the main house for polar alignment, at last! Alignment of the mount is carried out by viewing through the hole in the top right of the Polarie – better alignment can be achieved by using a polar scope which fits through the middle of the Polarie mount.

Once polar aligned, fixed on the front of the Vixen Polarie the camera then rotates to follow the celestial sphere and chosen object in order to achieve a sharp image with long exposures. For this purpose there are 4 tracking rates: sidereal, half sidereal, lunar and solar. With no interesting foreground here I concentrated on the sky by using the sidereal rate; for more scenic shots with the landscape incorporated, using half-sidereal provides a compromise in order to achieve a non-blurred image of the sky and landscape, though this method is inevitably limited to shorter exposures than sidereal.

Vixen Polarie mount on Manfrotto tripod – a lightweight, portable tracking method for widefield astroimaging

Vixen Polarie – close-up showing x2 ball head fittings

Vixen Polarie – tracking speed settings

VP Dial

Vixen Polarie with DSLR attached & ultra-wide lens

I have adapted a somewhat basic red dot finder to fit on top of the DSLR camera using the hot shoe, which was immediately helpful to accurately locate the desired target area. However, as previously experienced, once again achieving focus proved quite difficult, basically requiring just trial and error; I intend to look into a more efficient method but in the absence of a Bahtinov mask this is likely to be the best technique for now. A laptop can be used for image capture but maintaining the themes of portability and simplicity, I successfully used an intervalometer to control exposures.

Whilst initially my target was the Orion constellation, I’ve long held the ambition to image Barnard’s Loop, a much larger and elusive feature surrounding the constellation and more difficult to photograph. I had tried this before last January with limited success but ever since acquiring the Vixen Polarie this has been my No1 imaging goal.

Orion Constellation 220115 Stacked1L2C3GX (Large)

The Orion Constellation & Barnard’s Loop (up / north is left) : AZ-EQ6 Mount + Canon 550D & 200mm Telephoto | 180 secs @ ISO 1,600 & calibration | 22nd January 2015

Unable to see with the naked eye, only using long exposure photography unveils the majesty of Barnard’s Loop, an emission nebula to the left (east) of the Orion constellation. Shaped as a large-C, the loop completely encompasses the eastern side of the constellation and is thought to be a recent supernova front moving out from Orion and illuminated by stars from within the nebula, as well as part of the Orion Molecular Cloud Complex. Discovered and named after astrophotographer E. E. Barnard in 1895, at some 14^o or 300 million light-years across Barnard’s Loop is enormous; however, the entire Molecular Cloud is about 30^o in size!

pleyades31_02

The Orion constellation was originally conceived in Greek mythology as the Hunter, pursuing Taurus the Bull to the west, with the stars tracing out a shape of a hunter holding a shield and club in each hand, a belt around the waste with a sword attached. What they could not have known at the time is that he also has a head, in the form of the Lamda Orionis Nebula (Sh2-264), located centrally and above Betelgeuse and Bellatrix.

Barnard’s Loop & Lamda Orionis Nebula : Vixen Polarie & modded Canon 550D + Sigma UWA @ 20mm | 11 x 240 secs @ ISO 1,600 + darks | 7th January 2016

I was able to image Barnard’s Loop on 7^th and 14^th January; at ISO 1,600 the first images showed the Loop but certainly left room for improvement, as a result I shot the subsequent images at ISO 800 and obtained a noticeably better outcome – though I had to push post processing to reveal the features. The Loop and head are clearly evident but I’ve been intrigued to see other objects also revealed, albeit without the detail obtained with prime focus imaging using the telescope: Great Orion Nebula, Horses Head & Flame Nebulae and surprisingly on the left (east) of the Loop the Rosette Nebula. Looking at other’s images of Barnard’s Loop it is clear that I will need to take significantly more subs to properly reveal the full beauty of this wonderful and very large feature – dark skies would be nice too – but for the moment I am pleased with my first outing using the Vixen Polarie, which holds great promise for capturing a wider perspective of the Universe.

Barnard’s Loop & Lamda Orionis Nebula + Rosette Nebula on far left : Vixen Polarie & modded Canon 550D + Sigma UWA lens @ 20mm | 14 x 240 secs @ ISO 800 | 14th January 2016

Spaceship Earth

December 23, 2015 by grahamrob in Deep Sky Objects, Earth, General Astronomy, Software and tagged DSO Imaging, Earth, Monoceros, Orion, Solar system | Leave a comment

I’m now into my second year of ‘serious’ astronomy and astrophotography, which accompanied by a greater knowledge of the Universe has brought an element of familiarity: with the equipment, with viewing & imaging techniques and space itself. In the past I have worked underground as a geologist on mines and like to think that I have good spatial awareness. Through this growing familiarity and knowledge of the night sky, I have become increasingly aware of our place in the Universe and how we on Earth are travelling through space; I also feel a growing empathy other peoples such as mariners who use and relate to the sky and space in a way ordinary people do not.

Whilst spinning on its axis at 1,037 mph at the equator (653 mph here at Fairvale Observatory’s higher latitude), the Earth is moving at about 70,000 mph round the Sun. Furthermore, located in the Orion-Cygnus arm of the Milky Way, the Solar System is also moving around the spiral galaxy at 500,000 mph, resulting in a galactic year of nearly 250,000 Earth years . Notwithstanding these complex and frankly mind boggling statistics, it thankfully all feels quite serene when outside at night with my telescope at Fairvale Observatory.

Going back some 5,000 years the constellations might seem to describe the ‘shape’ of space and provide a sense of stability to the sky but this is misleading. These and other asterisms are 2D patterns that mankind has created for practical use, whereas in reality most of the stars that make up these patterns bear little if any meaningful relationship with each other when viewed in 3D – like this animation showing the true shape of Orion.

Furthermore, under the force of gravity and other as yet unknown influences e.g. dark energy, these too are moving through space in their own way at vast speeds. In reality the constellations are therefore anything but permanent and through the millennia their apparent shapes change and will eventually be destroyed as far as we on Earth are concerned. As with my professional subject geology, this is the problem with space – it is very big and the timescales are very, very large, essentially beyond human comprehension, which result in otherwise unimaginable events; this animation wonderfully illustrates the scale and complexity of the known Universe.

Space selfie = the insignificance of Earth.
The Pale Blue Spot photograph of Earth (right side of picture) taken 6 billion kilometers (40.5 AU) away by Voyager-1 on February 14th 1990,

The beauty of such a system is that it can be modelled very accurately, from which it is possible to predict with great certainty the projected position of all these celestial objects, thus making spaceflight and the prediction of astronomical events possible. Likewise using the same data modelling it is possible to look backwards at past events. Such computerisation is no longer just the preserve of NASA and University academics but is at our fingertips using a computer based planetarium, in my case Carte du Ciel – incredible!

Given the time of year I have therefore used the aforesaid programme to generate a view of the night sky from Bethlehem 2015 years ago on the morning and evening of 25^th December. Even then differences can be seen in the shape of the constellations compared to now. If we are to believe the story of the Three Wise Men following a bight ‘star’ at this time, it seems it would be most likely to be in the morning when first Jupiter and then Venus are present. Either way it’s fascinating to be able to model the night sky in this way for any chosen moment in time.

Santa's view of Bethlehem - actually from the ISS on 24th December 2011

Santa’s view of Bethlehem from the ISS on 24th December 2011

After weeks of cloud cover I recently managed to get outside again for what turned out to be a wonderfully clear night, from dawn to dusk, furthermore there was no Moon! As a result imaging was productive and included some exciting new objects. However, again given the time of year for the moment I am repeating an object used last Christmas. One year on the difference is that this time I have used a modded Canon 550D DSLR camera and thus improved (I think) the red Ha-light detail.

Cone Nebula & Christmas Tree Cluster WO GT81 + Modded Canon 550D & FF | 15 sec @ ISO 1,600 + calibration | 8th December 2015

Cone Nebula & Christmas Tree Cluster – right of centre
WO GT81 + Modded Canon 550D & FF | 15 sec @ ISO 1,600 + calibration | 8th December 2015

Cone Nebula (bottom centre) & Christmas Tree Cluster (inverted)

NGC 2264 or Christmas Tree cluster and its neighbour the Cone Nebula are located within the Monoceros AKA Unicorn constellation, which being part of the Milky Way are therefore inextricably linked to a similar destiny as spaceship Earth as it makes its way through space. Being some 2,700 light-years away we are unlikely to meet, though you never know with space and time!

HAPPY CHRISTMAS

Space Odyssey

October 9, 2015 by grahamrob in Deep Sky Objects, General Astronomy and tagged Andromeda, DSO Imaging, Galaxies, Messier Objects | 3 Comments

I have just finished reading Chris Hadfield’s excellent book An Astronaut’s Guide to Life on Earth, which is an entertaining and insightful look at being an astronaut and the lessons it provides for life in general. Who of us has not at least considered such an adventure ourselves but, of course, it is impossible for all but a few.

Astronomy is thought provoking enough in itself looking out at the vastness and beauty of the Universe, being in space and looking down on our planet would take such thoughts to a whole different level; from their subsequent accounts it is clear that those who have walked on the Moon became changed people, returning different to the rest of us.

Ever since following the pioneering space adventures of Yuri Gagarin and Alan Sheppard and especially watching the Apollo 11 Moon landing in 1969, I have been fascinated by space, its science and the human experience of travelling there. My solution to going into space was to take up scuba diving and since 1976 have had many wonderful diving experiences all over the world. Of course, it’s not space but it is very much other worldly and the weightless feeling is as close as most of us will get to being in space; the astronauts train extensively underwater for just that reason. Furthermore, as a geologist and more recently taking up astronomy has altogether provided me with a better understanding of the Universe.

Maldives, Kandooma 2004: the closest I’ll get to space!

Given my long standing interest in space, it is perhaps surprising that I came late to astronomy itself, so why now? The best answer is time – in recent years I have had more of it and in the past work, family and extensive travel precluded such a pastime. Like so many sciences in the modern era, technology has also unlocked major new opportunities for scientists and amateurs alike. Whilst I enjoy the science itself and especially viewing the night sky, the ability to produce frankly incredible images has been the most important key to my recent personal interest.

The phenomenal imaging improvements that have occurred since the launch of Hubble have made the power and beauty of the Universe even more accessible to us all on Earth. Digital image capture and processing is now so powerful that pictures of hitherto unimaginable quality can be achieved from Earth. Furthermore, for a relatively modest cost outlay, such images can be obtained by amateurs like me, literally outside my back door. More than any other development, this is what has now engaged my interest. The product of astroimaging can easily be overlooked as just an attractive, often spectacular photograph of the night sky – and they are. But the equipment and pictures produced are also important tools that can assist our understanding as well as imagination of space.

After a forced absence from astroimaging for the past six months, I was recently fortunate to obtain a number of exciting pictures of familiar objects on my first night back, in particular M31 or the Andromeda Galaxy. As the nearest galaxy to Earth, Andromeda is an obvious target for those new to astroimaging but despite its proximity, it is not to be underestimated as an imaging target. I have attempted imaging M31 before but, like many others, found it very difficult to coax out the detail which makes it such a beauty. I am not completely sure what was different this time but the resulting picture at last starts to capture these details; I was even more surprised at the outcome which is the result of just nine 120 second exposures at the end of a long night before heading for bed!

M31 Andromeda Galaxy
WO GT 81 + modded Canon 550D + FF | 9 x 120 secs @ ISO 1,600 | 19th September 2015

Andromeda poses two main challenges for the photographer: (i) the contrast in brightness between the central area and the rest of the galaxy, and (ii) the need to show the brown dust bands within the main disc, which provide a fascinating insight into the galaxy’s overall structure – that is not unlike out own Milky Way. The classic technique is to use two sets of images, with camera settings appropriate to the two contrasting areas, subsequently bringing them together during post-processing. Despite the limited number of prime focus images taken the final picture achieved still came out well. Though the bright central area is overexposed, the galaxy’s dust bands are clearly evident and for the first time have captured the full character of this magnificent feature. Furthermore, within M31 the NGC 206 is evident, a star formation region of over 300 new stars, whilst in the adjacent sky two other Messier galaxies are shown in the image M32 and M110.

M31 Anfromeda Galaxy: inverted & anotated

M31 Andromeda Galaxy: inverted & annotated

I think it is correct to say that the Andromeda Galaxy is one of the iconic images of the night sky and I feel obtaining such a picture marks another notable point in my personal space odyssey. I would hope Chris would approve, as well as Major Tom?

Earth’s Junkyard

August 19, 2015 by grahamrob in Earth, General Astronomy, Widefield Imaging and tagged Perseids, Satellites | Leave a comment

Only very recently the BBC Horizon programme covered the increasing problem of space junk that now orbits Earth forming a virtual cloud of debris posing a serious threat in general and, in particular, to future space activity: obsolete satellites, broken, damaged or even fragments from destroyed man-made objects. In addition to the ISS, communication and other satellites can often be seen passing overhead but in reality these only represent the tip of the iceberg.

Earth’s Junkyard
Computer-generated image of objects and debris currently being tracked orbiting Earth; it’s the stuff we can’t see or track that is most worrying!

Whilst visiting my daughter in Somerset at the weekend the night sky was clear and fantastically dark thanks to the New Moon and lack of light pollution when compared to Fairvale Observatory in Surrey. Having already tried to image the Perseids in the preceding week unsuccessfully, I thought I’d try again in these much better conditions using a basic DSLR on a tripod and an intervalometer.

Despite excellent seeing conditions, the air was cool’ish and therefore prone to quickly form dew on the camera lens after just 20 minutes or so. At the time it didn’t seem as though I had captured anything of interest, however, looking at the images subsequently on the computer, I was excited to find a bright flash appearing between two of the pictures pictures – what could this be, it seemed too short to be a Perseid? Whatever it is was had gone in the next image 5 seconds later. I discovered the anomaly whilst flicking from one picture to the next when suddenly a bright point stood out from the otherwise unchanging starry sky by blinking – a characteristic of something unusual taking place.

I posted a query on SGL and the overwhelming consensus has been that it is most likely to be a satellite or debris flare from the aforementioned space junk – either a spinning satellite or debris that briefly produced a reflection as it passed through the field of vision. Looking closely the bright spot does seem to be elongated from left to right, suggesting movement, though I am still perplexed why it has therefore not produced a more significant trace given the 30-second exposure being used – for a moment I even thought it might be a Super Nova!

Notwithstanding, it’s an interesting effect, though sadly seems to confirm the extent to which mankind has already made a mess of the space around our planet.

Image before the solar flare appears - red circle indicates the area of interest.

Image before the satellite flare appears – red circle indicates the area of interest.

Solar flare, indicated by the red arrow?

+ 5 seconds later a satellite / debris flare, indicated by the red arrow?

Notes: The pictures were taken at 10.37pm on 16^th August, looking north east, at about +70^o inclination using a Canon EOS 700D + 18-55 lens, at 18mm and f5.6. Both images are 30 secs exposure at ISO1,600 with an interval of 5-seconds. The area of interest is indicated with a red ring in the first image, with the white ‘object’ appearing in the following image shown by a red arrow.

180 Degrees

August 9, 2015 by grahamrob in Comments, General Astronomy, Viewing, Widefield Imaging and tagged Photography | 2 Comments

Viewing from Fairvale Observatory is far from ideal but I have no choice and need to make the most of it:

(i) Without going down the garden (which is not practical and would then totally obscure the southerly view) my house blocks the entire northern sky, critically including Polaris;

(ii) We have very high +/-12ft hedges surrounding the garden;

(iii) Directly east is a large house that completely obscures the horizon;

(iv) South east and south are very large trees;

(v) To the west is a wooded hill, thus blocking the horizon in that direction, and

(vi) Some 7-miles to the south is Gatwick Airport which produces significant light pollution, as well as aircraft that regularly fly through my images as well as others from Heathrow, also not far away.

It’s a miracle I am able to undertake any astrophotography and I long for the day I live somewhere with better conditions.

In the meantime I have to make do with the 180^o I have available. For the record and with great skies and good weather, this week I compiled a photo mosaic of the aforesaid view – which illustrates some of the aforementioned problems and is in itself an interesting picture. The scene is stitched together from six DSLR shots that encompass most of the east to west panorama but in order to achieve this, the resulting photograph becomes severely distorted.

The principal view is directly south, with the Meridian pretty much straight ahead. Low angle viewing and imaging is almost completely impossible but depending on the timing and some crafty shooting, the mid-angle objects can be accessed as they pass between the trees. The best imaging is therefore mostly restricted to a 20^o range between about 65^o and 85^o and within +/- 20^o of the Meridian; high angle east and west views are feasible but seeing in these directions is impacted by the greater atmospheric distance through which the light has to travel.

For now this is my night time playground: it is challenging and can be frustrating but with clear skies, preparation and patience it’s good fun and much can still be achieved.

Night sky panorama from Fairvale Observatory + obstacles: the tree on the left is very large +200 year-old copper beech, the coniferous trees due south are closer to the property boundary - thus increasing their impact on seeing. The red line on the left approximately marks the East and the central red line is the Meridian.

180 degree night sky panorama from Fairvale Observatory + obstacles: the tree on the left is a very large +200 year-old copper beech, the coniferous trees due south are closer to the property boundary – thus increasing their impact on seeing. The red line on the left approximately marks the East and the central red line is the Meridian.

Equivalent Cartes du Ceil planetarium view at the same time.

Canon Koppernigk’s Conjunction

July 3, 2015 by grahamrob in General Astronomy, Solar system, Viewing, Widefield Imaging | 5 Comments

This time of the year is something of a fallow period for astronomers: short nights combined by with the complete absence of astronomical darkness and fewer DSOs. I have personally found this year more difficult than usual as since April 25^th, following an operation to replace my left knee, I have been physically unable to set-up Fairvale Observatory and undertake astronomy of any sort. Notwithstanding, once over the initial few weeks of pain, I have tried to use the extra time afforded me usefully.

I have been reading Arthur Koestler’s excellent book The Sleepwalkers, which charts the history of man’s understanding of the universe and astronomy. Speaking of fallow periods, in the book I’m just past the very long period of inactivity and general superstition regarding the cosmos that occurred during the Middle Ages, which followed the more enlightened thinking of the Greeks, particularly Pythagoras; taking account of the Greek’s progress in understanding the Universe, our astronomical knowledge might have been 1,500 years more advanced today were it not for this prolonged medieval hiatus! Fortunately Copernicus (his better known Latin name) finally initiated what has become today’s heliocentric model of the Solar System, although his seminal work On the Revolutions of the Heavenly Spheres was only published just a few hours before his death after a delay of 30-years, such was his reluctance to put forwards such thoughts at that time.

Next, I have just completed the 6-week AstroTech MOOC course organised by Edinburgh University, which covered the scientific logic behind astronomical discoveries and the technology that lies behind them. This was my third astronomy MOOC and provided some interesting insight into telescope and imaging technology, as well as filling time during my recovery.

Finally, as my (limited) mobility has slowly started to improve, the night sky has recently provided a fascinating show of its own that did not require the observatory’s paraphernalia and, furthermore, beautifully demonstrated the principles originally outlined by Copernicus in 1543.

During the latter part of June Venus and Jupiter moved inexorably towards very close conjunction by the end of the month. Reaching just under ¾ of a degree separation on 30^th June and 1^st July this is a rare event, which with a clear sky could be easily viewed with the naked eye. Better still, I set out to photograph the two planet’s journey during the preceding 12 days, thus illustrating Copernicus’ revolutions around the sun of these two heavenly spheres. Whilst any school child will today understand this process, it is a frightening thought that belief in such a mechanism could once have led to the death penalty!

Obscured from view at Fairvale Observatory as Venus was just 17 ½^o above the western horizon, I had to travel to a nearby location which provided a clearer westerly viewpoint of both planets at their low attitude. In order to obtain a series of comparable images and thus show the real spatial changes occurring up to conjunction, all pictures were taken from exactly the same location. With my Canon EOS 700D fixed on a photographic tripod I shot a series of images over a 50 minute period using either the 18mm or 55mm telephoto settings, playing with ISO and speed settings as darkness progressed; this was roughly the time the two planets took to disappear below the Earth’s horizon after achieving Civil Darkness.

The resulting photographs show Jupiter apparently advancing on Venus before at conjunction ‘passing’ close by on the aforementioned days. Whilst Jupiter is the third brightest object in the night sky (after the Moon & Venus) and nearly 12 times the size of Venus or 1,400 times by volume, the planet looks very small by comparison to Venus. This of course is the effect of perspective, with Jupiter currently some 565 million miles distance from Earth, whereas Venus is only 48 million miles; furthermore although at -1.8 the apparent magnitude (brightness) of Jupiter is high, at -4.4 Venus is much brighter.

18th June 2015: Jupiter left, Venus right – trees on the horizon provide a reference scale as the planets move towards each other during the month in subsequent photographs.

25th June 2015 + 7-days

30th June 2015 + 5 days. Nothing – dark thunder clouds completely obscure the western sky during conjunction!!!

1st July 2015. Bingo = conjunction; though one day later Jupiter has now moved to the right of Venus.

1st July 2015. Close-up of the conjunction using 55mm telephoto setting and ISO 400 - Venus now left & Jupiter right.

1st July 2015. Conjunction close-up using 55mm telephoto setting and ISO 400 – Venus now left & Jupiter right.

Unfortunately I am expecting it will be at least another month before I have recovered sufficiently to consider setting-up Fairvale Observatory again, by which time Astronomical Darkness will thankfully be slowly returning. In the meantime I’m looking forwards to the next section of The Sleepwalkers which covers Kepler and Galileo and hopefully exciting developments from the New Horizon Pluto fly-by and more from the Rosetta Mission and the re-awakening of its Philea lander. Given clear skies there should also still be plenty to see without the observatory: The Perseids, Saturn and of course at the centre of our Solar System as determined by Copernicus, the Sun, which will be at aphelion on 6^th July – though you wouldn’t think so judging by the high temperatures currently prevailing in the UK and Europe!

Big Cat Hunting

February 26, 2015 by grahamrob in Deep Sky Objects, General Astronomy, Imaging and tagged DSO Imaging, Galaxies, Leo | 1 Comment

As we move closer to the Spring Equinox, the winter sky is already rapidly disappearing towards the western horizon and I have been left wondering what next? I was concerned that after successfully imaging the Orion constellation and all its spectacular parts over the past four months, it would be a difficult act to follow, I needn’t have worried. Already starting to appear from late-evening, a series of constellations are about to proceed across the night sky over the next few months which will provide an equally spectacular but different kind of show to Orion.

First of these is the constellation Leo, the celestial Lion, which it turns out is packed with galaxies and double stars. The asterism of Leo is in the shape of a lion which, being dominated by various groups of galaxies holds much imaging promise, with my 81mm telescope providing an ideal field of view.

Located behind Leo’s rear ‘leg’ is the best of these, known as the Leo Triplet or M66 Group, which consists of three galaxies: M66, M65 and NGC 3628. Evidence suggests that these are linked in a gravitational dance with each other which, in the case of NGC 3628, has created a disturbed, unbarred galaxy with a faint 300,000 light-year star to the east. M66 is an intermediate spiral galaxy, with a diameter of about 95,000 light-years and is the largest and brightest of the trio. M65 is a smaller, barred intermediate galaxy. The field of view has also captured other galaxies as well as the orange giant star 73 N Leonis. All-in-all a wonderful image which I hope to return to in order to achieve even better detail using longer exposures, guiding and hopefully a larger telescope one day.

Leo Triplet: M66, M65 & NGC 3628
WO GT81 + modded Canon 550D & FF | 10 x 180 secs + calibration @ ISO1,600 | 21st February 2015

To the west of the Leo Triplet, in the direction of Leo’s dominant star Regulus, is another triple collection of galaxies called the M96 Group. While a little fainter that the Leo Triplet, the M96 Group nonetheless makes a wonderful image accompanied, as it is, by numerous other galaxies and stars. Of the latter, the giant orange 52 K Leonis star dominates the scene.

M69 Group: M105, NGC 3373 & NGC 3371 + other galaxies and orange giant 52 K Leonis WO GT81 + modded Canin 550D & FF | 10 x 180 secs & calibration @ ISO 1,600 @ 21st February 2015

M96 Group: M95, M96, M105, NGC 3373 & NGC 3371 + other galaxies and orange giant 52 K Leonis
WO GT81 + modded Canon 550D & FF | 10 x 180 secs & calibration @ ISO 1,600 @ 21st February 2015

It’s fair to say that the results of my big cat hunting around the constellation Leo have been a pleasant and successful surprise, with further promise still to come as Spring develops. Watch this space!