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

Rock On!

October 19, 2015 by grahamrob in Deep Sky Objects, Equipment, Imaging, Widefield Imaging and tagged Andromeda, Cygnus, DSO Imaging, Nebulae, Photography, Star Clusters | 2 Comments

Due to my viewing limitations at Fairvale Observatory planning is essential, with the best imaging range mainly restricted to a zone between 65^o and 85^o and within +/-20^o of the Meridian. Furthermore, as I am mostly using the William Optics GT81 telescope at the moment, imaging targets should preferably be large – something between 1^o& 2^o is perfect, such as the Rosetta Nebula at 1.3^o or Andromeda Galaxy at 190’ x 60’. As luck would have it these conditions are favourable for a number of objects at the moment and I have been somewhat spoilt for choice: North America Nebula, Veil Nebula and Andromeda.

Notwithstanding, for some reason I have until now overlooked the Sadr Region IC 1318, which is also large and in a similar part of the sky as the aforementioned North America and Veil Nebulae but perhaps overshadowed by their notoriety. In reality it is an enormous area of nebulosity containing many features worthy of imaging which are perfect at this time of the year from my location.

Sadr Region: green rectangle indicates the approximate area of IC 1318 image, yellow rectangle the NGC 6888 Crescent Nebula image.

IC 1318 is a diffuse emission nebula surrounding the star Sadr or Gamma Cygni, which is at the centre of the Cygnus Cross and on the plane of the Milky Way. The Sadr region is located deep within the Orion arm of the Milky Way about 3,000 light-years from Earth, with Gamma Cygni actually situated closer in the foreground. Such is the size of IC 1318 that its three constituent parts, A – B – C, extend over some 200 light-years or about 4 degrees, which is well beyond the FOV of the WO GT81; how could I have overlooked his enormous area of nebulosity before? As a result of its size and complexity I also chose to image two other interesting features nearby.

IC 1318 Sadr Region – image inverted & annotated

IC 1318 Sadr Region
WO GT81 + modded Canon 550D & FF | 30 x 120 secs @ ISO 1,600 | 30th September 2015

Situated just above Sadr is the small star cluster of NGC 6910 AKA Rocking Horse Cluster. Although only 10’ in size the cluster is visually quite prominent, though I struggle to see the little horse that others have identified. Notwithstanding, it is an interesting and attractive part of the Sadr region.

NGC 6910 The Rocking Horse Nebula as recorded by StarObersever.eu – located just above Gamma Cygni in the previous image.

Located about 2 degrees south west of Sadr is the Crescent Nebula NGC 6888, which is not unlike the Jellyfish Nebula in appearance but is younger in its evolution. An emission nebula, NGC 6888 is formed by a stellar wind from the Wolf-Rayet star WR 126 colliding with a slower moving wind ejected when the star previously became a red giant. The result is an illuminated shell-like feature consisting of two shock waves, one moving inward and the other outward, producing this amazing spectacle which measures some 25 light-years across. Near the end of its existence, the star will eventually end its life in a spectacular supernova explosion – now that would be an image.

NGC 6888 Crescent Nebula
WO GT81 + modded Canon 550D & FF | 20 x 180 secs @ ISO 1,600 | 9th October 2015

Crescent Nebula – cropped

Crescent Nebula – GradientXTerminator applied

Whilst IC 1318 has proved to be an excellent and productive imaging target for my equipment, it has become clear that it represents a much, much larger area of nebulosity that incorporates or is at least immediately adjacent to NGC 7000, the North America Nebula. At a rough estimate this larger area spans a distance of some 2,000 light-years and is some 50-times bigger than the Sadr region. Like other major areas of nebulosity (Barnard’s Loop) such a scale is way beyond the ability of my equipment and most others without resorting to a mosaic technique.

However, my interest in seeing and potentially imaging the bigger picture has been piqued and I have recently purchased a Vixen Polarie tracking mount, which can be fixed onto a camera tripod with a standard camera and lens in order to take long exposures without forming star trails. This set-up has two advantages over prime focus + telescope imaging: (i) it is highly portable and can easily be taken anywhere in a rucksack, and (ii) by using a camera lens of say <=50mm focal length it is possible to achieve a much wider FOV and thus photograph some of these very large nebulous areas in one image.

Alas the Sadr region is now moving on and it is probably too late to tackle using the Polarie mount but it will be something to look forwards to again next autumn and meanwhile Orion is just round the corner. Watch this space for developments!

The Pelican & The Phoenix

September 22, 2015 by grahamrob in Deep Sky Objects, Equipment, Imaging and tagged Cygnus, DSO Imaging, Nebulae | 2 Comments

As we pass the Autumn Equinox the promise of long and exciting Winter skies is not far off but there are still some wonderful late Summer features around worth imaging before they move away from the Meridian and out of view from Fairvale Observatory. Following a major operation earlier in the year I’ve been unable to move the heavy equipment outdoors until very recently and have therefore almost completely missed the Summer skies; even as I’ve been getting better in recent weeks, poor skies and other circumstances have stopped my return to astronomy – until now.

Up until shortly before midnight the Cygnus constellation is favourably located close to the Meridian at the moment and at a very high, southerly altitude – perfect for my location – it was therefore here that I chose to make my long awaited resumption to astroimaging last Saturday. The weather forecast in the morning showed clear skies for that night but by early evening had changed to cloud and looked like being another lost opportunity; on this basis the Flamsteed Astronomy Society had already cancelled their planned evening astronomy session. However, unlike previous attempts in recent weeks when clear skies were forecast and the cloud rolled in unannounced, this time the outcome was very different, with a clear moonless sky throughout the night – I sometime wonder if the weather forecasters have windows and bother to look outside!

Located northeast of the first magnitude star Deneb and some 1,600 ly from Earth is NGC 7000 or the North America Nebula, an enormous H II region that in outline resembles the North American continent. I first encountered this emission nebula at a similar time last year, which was my first experience of such a feature and I was therefore thrilled to capture part of it in my picture; my blog title at the time captures my feelings – WOW! However, taking the image using the longer focal length Skywatcher 150PL with a smaller field-of-view (FOV), the picture only captured part of the ‘USA’ and the ‘Gulf of Mexico’. Furthermore, using an unmodded camera much of the red H-alpha light that is characteristic of these nebulae was not recorded.

Since then my equipment has changed in a number of important ways, so that the William Optics GT81 with a wider FOV would now enable me to image more of the nebula, whilst using a modded DSLR camera would also record much more of the H-alpha light; an additional year’s experience also helped. This time my target was the related IC 5070 and IC 5067 H II regions otherwise known as the Pelican Nebula, situated just west of NGC 7000 and close to Deneb.

The Pelican Nebula, IC5070 & IC 5067. WO GT81 & modded Canon 550D + FF | 30 x 120 secs @ ISO 1,600 + calibration | 19th September 2015

The Pelican Nebula, IC5070 & IC 5067
WO GT81 & modded Canon 550D + FF cropped | 30 x 120 secs @ ISO 1,600 + calibration | 19th September 2015

With an apparent magnitude of +8 the Pelican is generally less bright than its larger +4 neighbour but is no less exciting. The bright double star Cygnus 57 and binary Cygnus 56 shine conspicuously just in front of the ‘bird’ and within the ‘body’ respectively. In addition a bright area at the northern top of the ‘bird’s head’ is an active area of star formation, which ionizes the gases creating the glowing red area.

Whilst missing the impact of being my first H II nebula last time, the larger image of the North America Nebula now captures most of the ‘continent’ and encompasses ‘Central America’. As a result the picture clearly shows the Cygnus Wall, another bright area of star formation that runs along ‘Baja California’ / ‘northern Mexico’ area.

NGC 7000 The North America & Pelican Nebulae
WO GT81 + modded Canon EOS 550D + FF | 30 x 120 secs @ ISO 1,600 + calibration | 19th September 2015

The combined Pelican and North America Nebulae span some 50 ly across, which when imaged together makes a wonderful picture of these spectacular features. I would be happy with this image at any time but after nearly six months away from astroimaging it’s a very pleasing result. I feel re-invigorated, like the phoenix has risen again.

Parting Shot

February 14, 2015 by grahamrob in Deep Sky Objects, Imaging, Software and tagged DSO Imaging, Nebulae, Orion | 6 Comments

I thought I was finished with Orion for this winter but a high pressure system and clear weather provided an unexpected opportunity on Sunday evening that I couldn’t resist. The good news: as Orion is passing the Meridian by 8.00 pm it provides an early start. The bad news: being near Gatwick Airport, at this time of the evening the sky is full of aeroplanes at Fairvale Observatory, most of them flying directly through the Orion field of view!

With such good weather, I also decided to try out computer control for the first time. I installed EQMOD before Christmas and have since been reading and watching tutorials on its use and experimented operating with it indoors. Frankly I am somewhat intimidated by the large collection of software that is required to go to the next level with imaging and EQMOD is just the first step. However, eventually I just have to do it and this would be the night to start!

EQMOD is a software project written and run by enthusiasts which provides computer control to the mount, thus dispensing with the SynScan handset. It also does much, much more and in general provides far superior control and flexibility, in particular linking control with a chosen planetarium programme – usually either the excellent Stellarium or Carte du Ciel, all of which is free!

Notwithstanding, I still have the major problem of polar alignment as my house completely obstructs all views of the northern sky. For the moment I adopted a belt-and-braces approach, first achieving polar alignment using the SynScan routine before switching to EQMOD control; once comfortable using EQMOD I plan to try out alignment software called Alignmaster, which I hope will allow me to completely dispel with SynScan. On this occasion EQMOD worked a treat. For alignment, just clicking on the object you want to see in the planetarium software (with which EQMOD is linked), the telescope slews and after accurately aligning the scope with the star you press a sync button. It’s so quick that it is easy to rapidly establish five or six (or more) star alignment points, thereby constructing a triangular matrix from which the mount can then track more accurately. There are many other features I have yet to use but so far I like what I see and am in awe of those who have written and maintain the system.

With EQMOD computer control thus established successfully, I set out to image some old ‘friends’ in Orion. Having only recently acquired a modded Canon 550D, it seemed only right to take another look at M42 the Great Orion Nebula and The Flame and Horsehead nebulae.

The impact of modification was immediately evident with M42, it now being much redder than before and with greater detail exhibited in the nebulosity. The tracking also looked OK, though a few stars looked a little bloated, suggesting there’s still work to do on another day i.e. autoguiding.

Orion’s Sword: M42 The Great Orion Nebula, Running Man Nebula & NGC 1981 Star Cluster
WO GT81 + modded Canon 550D & FF | 10 x 180 secs @ ISO 800 & darks calibration | 8th February 2015

The Flame and Horsehead nebulae also show similar improvements and, in the case of the Horsehead, the actual ‘head’ is much clearer than before.

NGC 2024 Flame Nebula & Horsehead Nebula WO GT81 + modded Canon 550D & FF | 10 x 180 secs @ ISO 800 & darks calibration | 8th February 2015

NGC 2024 Flame & Horsehead Nebula; NGS 2023 relection nebula just below/left of the Horsehead
WO GT81 + modded Canon 550D & FF | 10 x 180 secs @ ISO 800 & darks calibration | 8th February 2015

With Orion by now well past the Meridian and the weather holding up well I then decided to try my luck once again with Jupiter, which by now is well located high in the south east sky. Unfortunately like sport, astronomy is a game of two halves. Following the success using EQMOD my experience with Jupiter was a complete failure.

I had previously encountered significant problems with my webcam last year, that mostly stemmed from problems with the capture software and it was here that I was to stumble (fall more like it) once again. Initially Firecapture seemed to boot up OK and recognised the camera, though try as I may I could not see Jupiter on the screen; I knew it was there as I had previously centred and focussed it there. I therefore decided to reboot the software, which was a big mistake. This time Firecapture would not recognise the camera and on trying to de-bug the problem I ended up with the dreaded ‘black screen of death’. Here was the downside of computer control, with the black screen going nowhere I also lost all control of the mount! I therefore retreated to SynScan, parked the telescope and deliberately crashed the computer; I have not yet investigated the problem further since then – watch this space!

It was therefore something of an ignominious end to the evening. However, I was still buoyed by the earlier success of EQMOD and more than happy with what may be my parting shot of Orion for this winter. Au revoir.

Horsehead Nebula with the NGC 2023 reflection nebula, bottom left

Raising the bar

January 5, 2015 by grahamrob in Deep Sky Objects, Equipment, Imaging and tagged DSO Imaging, Nebulae, telescope | 8 Comments

My short astroimaging journey has been marked by a number of challenges, which looking back can now be viewed as important steps and achievements that have made it all worthwhile.

First trying to get a recognisable astronomy picture of anything using a compact camera: widefield on a tripod or afocal through the telescope eyepiece. Afocal imaging was surprisingly difficult to do well, even when using a camera clamp. Eventually I managed to obtain a crude photograph of the Orion Nebula, which nevertheless showed its colour and the Trapezium star cluster. Whilst basic, at the time I was very pleased and found the capture of the nebula’s light itself something of a seminal moment for me; using a basic compact camera, it had been possible to reveal hithero unseen colours and nebulosity. I wanted more.

M42 The Great Orion Nebula
Afocal image | February 2014

Next, with the objective of achieving basic images of other iconic astronomical objects, I adopted two paths using (a) an astronomy webcam, and (b) a DSLR camera. At this stage I had added RA and DEC motor drives to my EQ3-2 mount, which then allowed the telescope and attached camera to track the desired object and thus achieve longer exposures required to improve quality and detail. However, this set-up was still quite basic, with exposures of no more than 20 seconds possible without producing star trails. Furthermore, finding the desired objects and focussing remained quite difficult.

M45 The Pleiades Canon 700 D DSLR + 150PL Newtonian relfector + x2 Barlow |February 2014

M45 The Pleiades
150PL Newtonian relfector + EQ3-2 mount + Canon 700D + x2 Barlow |February 2014

Mars 150PL Newtonian reflector + EQ3-2 mount + ZWO ASI 120 MC webcam + x2 Barlow | May 2014

The breakthrough came in June 2014 when I acquired an AZ-EQ6 Mount, which when properly aligned significantly improved tracking accuracy and thereby extended exposure times of up to 180 seconds; for various reasons this was not easy to set-up properly and took some months to master. At the same time I also obtained a William Optics GT81 apochromatic triplet refractor telescope which, in combination with the mount, held the prospect of even better astrophotography.

Since then I have slowly been trying to, (i) learn how to use all the various facets of the new equipment, and through this (ii) to improve the quality of my images and tackle new, hitherto unseen features. I have made good progress with the equipment in recent months, although there is still much untapped potential. However, improved imaging is now revealing the otherwise inaccessible world of Deep Sky Objects that is nothing less than incredible, exciting and very rewarding.

M57 Ring Nebula, close-up with polar alignment. Canon 700D | 24x30sec @ ISO 1,600

M57 Ring Nebula
William Optics GT81 + AZ-E6 GT mount | Canon 700D | 24 x 30 secs @ ISO 1,600 | September 2014

M45, The Pleiades or Seven Sisters star cluster Canon 700D unguided | 26 x 90 secs darks/bias/flats @ ISO 800

M45 The Pleiades or Seven Sisters star cluster
William Optics GT81 + AZ-EQ6 GT mount (unguided) + Canon 700D DSLR| 26 x 90 secs darks/bias/flats @ ISO 800 | October 2014

The Orion Nebula October 2014 - the secondary feature in the top left corner is another nebula, M43. Orientated with equatorial North up and East to the left. Canon 700D unguided | 20 x 90 secs + darks/bias/flats @ ISO 800

M42 The Orion Nebula
William Optics GT81 + AZ-EQ6 GT mount (unguided) | Canon 700D + field flattener| 20 x 90 secs + darks/bias/flats @ ISO 800 | October 2014

At this time of the year it is necessary to grab every opportunity possible for imaging and so it was last Monday. With the new, waxing Moon dominating the sky until about 10.30 pm and the probable onset of dew, or worst still frost sometime after midnight, the window of opportunity was likely to be limited and cold. As it turned out, when I started to set-up and align the equipment at 9.30 pm it was a balmy 4^oC, which subsequently cooled to less than 2^oC by midnight and -1^oC when I packed up after 2.00 am. However, the relative humidity during most of this time varied only between 75% and 78%, thus delaying the onset of dew and eventually frost until shortly before 2.00 am.

The wonderful Orion constellation still dominates the sky at the moment but having recently ‘discovered’ the Monoceros constellation, I wanted to continue to get better acquainted with some of its exciting objects as well as something new in Orion. Shortly before Christmas I managed to image my first Monoceros target, NGC 2264 or the Christmas Tree and Cone Nebulae. Whilst pleased with the outcome of this seasonal object, the image suffered from noise and some lack of detail arising from the pre-dominance of Ha-light which my unmodded camera is unable to record – note to Father Christmas, modified DSLR in 2015 please. I was concerned that my next object might suffer from the same problem but in the short imaging time I had available, was determined to improve the quality through better alignment, more subs and longer exposures of 120 seconds at ISO 1,600. The result was excellent and, I believe, shows how far I have come with astroimaging since my earlier afocal photographs just over one year ago. Practice + perseverance + patience = results (sometimes).

The main target this time was the Rosette Nebula, situated to the south west of NGC 2264. This giant molecular cloud of hydrogen gas consists of four nebulae (NGC 2237, 2238, 2239 & 2246), some 130 light-years in size with an open star cluster at the centre – NGC 2244. At about 5 million years old, these superhot stars are young and still being formed, with a brightness estimated to be some 400,000 times greater than our Sun. It is the energy and light from these stars that excites and illuminates the surrounding Rosette Nebula, which itself dominates the image.

NGC 2244 Rosette Nebula
William Optics GT 81 + AZ-EQ6 GT mount (unguided)+ Canon 700D DSLR| 30 x 120 secs @ ISO1,600 | 29th December 2014

Amongst various definitions, a rosette is the French diminutive of rose. It is also an award given for achievements. I’d like to think that this image captures both of these definitions – as a beautiful red, rose-like nebula and my personal award to mark a another milestone in my quest over the past year. A rosette may also typically be awarded to the winners at a show jumping or similar sporting event – in a comparable way, it’s now time for me to raise the astroimaging bar higher in 2015.

Reflections – 2014

December 31, 2014 by grahamrob in Astronomy holidays, Comments, Deep Sky Objects, Equipment, Imaging, Solar system, Viewing and tagged DSO Imaging, La Palma, Moon, Nebulae, Saturn | 1 Comment

2014 has been my first full year of astronomy and I thought it would be useful (for me) to recap, thereby hopefully providing some encouragement and momentum for 2015. It’s been a good year which I have enjoyed but it only gets a little easier, slowly, and I can see many challenges ahead.

JANUARY TO MARCH

At the start of the year I was still getting to grips with my original basic equipment, purchased in 2013 as an introduction to astronomy to see if I liked it: EQ3-2 mount, Skywatcher 150PL telescope and two basic Plössl eyepieces and Barlow. Though good, the shortcomings of the equipment quickly became apparent even for modest viewing tasks, so I soon made some important additions. In no particular order these were: RA and DEC motor drives, a Telrad finder and two better quality, wide-angle eyepieces. All of these items made a noticeable improvement to my astronomy and eventually my growing interest in astrophotography.

As a result, at the start of the New Year I decided to purchase a Canon 700D DSLR camera, which has since opened up a whole new world, literally. I have considerable SLR experience and had been using a compact digital camera for some years but the need to understand and use the technology embodied in a DSLR for astrophotography is, as they say, a whole new ball game.

At this stage, my approach to astronomy was to try and learn the basics first by using basic equipment, thereby understanding the nuts and bolts of astronomy before moving on to more technical processes and software driven equipment. Moreover, I hoped such an approach would provide a good, long-term foundation of knowledge to undertake more ambitious tasks one day; walk before you run.

Although a member of the Flamsteed Society, its location at Greenwich does not lend itself to regular, on-the-ground astronomy from which I might otherwise learn first-hand from other members. Unfortunately more local clubs are also absent, so the learning curve has been steep and mostly personal and hands-on, though I must recognise the extensive and generally excellent help gleaned from the internet and various astronomy blogs, noteworthy of which has been Stargazers Lounge. I have often been disappointed by some of the retailers who, in my experience don’t relate well to customers and / or provide clear, helpful guidance or adequate aftersales support. My interpretation is that they consist of persons who have probably started astronomy shops as an extension of what was previously a hobby and often lack the commercial and personal skills required for such a business. Thankfully there are exceptions and it is they who I shall return to with my business in the future, whenever possible.

Date	Object*	Feature / Name
Feb	Jupiter	Afocal Images
	Moon	DSLR mosaic
	Greta Orion Nebula	Afocal Images

*Record of photographic images taken in 2014

APRIL TO JUNE

By now I knew I wanted to pursue astronomy as a hobby and, in order to fast track my learning process and experience the subject at a higher level, I undertook a one week astronomy course at the private Tacande observatory in La Palma. The equipment there was outstanding and so was the night sky and guidance provided by the owner, Joan Genebriera. Afterwards I was hooked and my aspirations were sky high, literally.

Virgo Group – Galaxy Supercluster| Canon 350D from Tacande Observatory, La Palma

Returning from La Palma brought me back down to Earth, however, undeterred I felt it was time to try my hand at webcam planetary imaging. On the face of it easy but, as usual, looks can be deceiving. Online advice indicated that it was possible to adapt and rig-up an old webcam for such purposes but my attempts to do so using a spare Logitech webcam only ended in misery. I therefore decided to bite-the-bullet and purchase a more suitable, off-the shelf one. The Holy Grail for entering webcam imaging is apparently the Philips Toucam but alas it is no longer made and finding one second-hand is very difficult. I therefore soon realised that it would be necessary to purchase a new webcam and, furthermore, it made sense to get one which was specifically made for astrophotography, the theory being it would work out-the-box. As a result I purchased the ZWO ASI 034 MC colour webcam but, despite my best efforts was unable to get a picture and decided to visit the retailer in person, determined to find out if it was me or the camera; as it turned out it was neither.

The first problem turned out to be the camera software SharpCap, which despite assurances, would not work with the camera. Next, for reasons I still don’t understand, the alternative FireCapture software would also not work until a more up-to-date version was downloaded. Notwithstanding, it also became evident that the camera would not work through a USB 3.0 port – though at the time this was not specified anywhere in the accompanying literature. Finally, with the camera plugged in to the USB 2.0 port and the up-to-date version of FireCapture, it worked! Getting to this point took me countless hours at home, a long trip to the retailer (who was very helpful) and then still some 2-hours to get it working. So much for working out-the box! This again seems to be a feature of astronomy.

From this and other experiences with equipment, software and manufacturers I have concluded that the world of astronomy is fraught with unnecessary problems often arising from just inadequate advice (see previous comment). It is assumed, by others: manufacturers, retailers or more technically minded astronomers, that the user will possess similar skills to make things work but, as many /most of us are newcomers this is, to say the least, an unhelpful assumption. I have therefore learned that the internet is your friend. Through the use of various online sites and blogs, other astronomers have given their very helpful and often not inconsiderable time and advice, for which I am eternally grateful.

Whilst this was all happening at the retailer, I took the time to review the camera I had purchased more closely and at the last moment decided to exchange it for the inevitably more expensive ZWO ASI 120 MC version, which unlike the 034 MC version can be used for autoguiding – I hoped futureproofing the purchase, time will tell. It is interesting to note that the current version of this camera (a) comes with different software and (b) has been upgraded to work with USB 3.0 – well why wouldn’t it in the first place, as most computers now use this specification? This suggests to me: did they really think about the camera’s design and operation properly at the beginning? However, following this breakthrough using the webcam for imaging was still to provide its own problems, which I am still grappling with.

SW 150PL x2 Barlow & ZWO ASI 120 MC

Using the ZWO ASI 120 MC I first started imaging Saturn, with some success. However, using the EQ3-2 mount to find, focus and image was very difficult, especially when I tackled Mars. In this case the size of the planet makes all the aforementioned issues even more difficult but, after lots of attempts I managed to get an image – altogether with plenty of room for improvement but satisfying nonetheless. I subsequently discarded the webcam in favour of the DSLR, with which I am more comfortable and due to the lack of suitable, mostly planetary objects through the summer period. With the return of Jupiter in recent weeks and the prospect of using the ZWO webcam for autoguiding, I have returned to using it again but given the time that has since elapsed, I need to relearn its use all over again!

At this point I had concluded that I wanted to pursue astronomy and astrophotography. I was also drawn inexorably towards astroimaging DSO objects; they provide numerous, albeit more difficult targets at all times of the year and I have found their combination of otherworldly beauty and science fascinating – I am now on a slippery slope that I feel will last for years! The implications of this conclusion and based on what I had learned over the preceding year about my basic equipment had only one consequence, I needed better equipment. There are astronomers who will say this hobby can be done cheaply, frankly I don’t believe it. Even buying second hand and generally making-do, the need for another piece of equipment never seems to stop – ask my wife.

Resigned to this course of action and the inevitable extensive analysis of what equipment was best suited, I reached a conclusion of what equipment I needed surprisingly quickly, though still prevaricating over innumerable makes and models available. In the end I purchased an AZ-EQ6 GT mount and William Optics GT81 FPL3 triplet achromatic refractor. I could have shaved £400 to £500 off the cost by purchasing other very good but cheaper makes and models but the WO is a beautifully tactile piece of obviously very well made equipment, which is a pleasure to own and use. I had originally intended to purchase an HEQ5 mount but on taking the long view (no pun intended) and considering the superior and critical payload capacity decided to move up to the EQ6, which then became the AZ-EQ6 GT for its superior belt driven mechanism and even better payload.

Date	Object*	Feature / Name
April	M104	Sombrero Galaxy
	M1	Crab Nebula
	M3	Globular Cluster
	M84	Lenticular Galaxy
	M95 & M96 Group	Spiral Galaxy
	Virgo Group	Supercluster of Galaxies
	NGC 4435/38	The Eyes (Nonet) Galaxies
May	The Moon
	Mars
	Saturn

JULY TO DECEMBER

The absence of good astronomical darkness approaching the Summer Solstice at the end of June and onwards until later in August, makes imaging difficult at this time of the year. Furthermore, the summer skies are generally less interesting and altogether provide limited opportunities. As a result the one object remaining, that hopefully dominates the sky at this time of the year, is the Sun. It was therefore time to start solar astronomy.

Given the obvious dangers I approached the task carefully, getting a made-to-measure Baader Astro Solar filter for use with the Skywatcher 150PL. Rightly or wrongly, at this initial stage I decided to use the 150PL as I figured the larger, open design of the Newtonian reflector would help cooling. The result was fascinating, with sun spots and general surface granulation clearly visible. However, the set-up has two drawbacks: (i) the resulting FOV is small and requires six or more images to cover the whole of the Sun, and (ii) such a filter only produces a view of white light, not allowing the more spectacular features evident at a other wavelengths, such as prominences, to be viewed. For this a considerably more expensive solar telescope or highly specialized filters are required – such is the fascination of our local star I can see the time I will want to pursue this branch of astronomy further.

Sun Mosaic
SW 150PL + Baader Astro Solar Filter + Barlow x2 | Canon 700D DSLR

Having since used the new equipment for nearly six months now I have no regrets – you get what you pay for. However, as usual there have been problems to overcome. The mount is very solid and was a real pleasure to use but from the outset I have faced one big problem – polar alignment. With no view of Polaris or any of the northern sky, as my house is in the way, combined with restricted views to the south, east and west due to adjacent housing and trees, the only options were drift alignment or the polar alignment routine that I latterly discovered in the SynScan handset. For the moment the SynScan method has become my preferred technique but it can still be problematical, as it is quite fiddly and often the stars chosen by SynScan are not always visible e.g. it is not uncommon that at times all the alignment stars provided by Synscan are located in the northern sky and cannot be seen because of the aforementioned problems. However, I am getting better and with diligence and patience can now get to within 30” or less of true polar alignment, which has allowed exposures of up to 180 seconds. I have tried drift alignment a few times but have difficulty finding suitable stars on the horizon, as I basically don’t have an horizon! Going forwards I am considering the use of Alignmaster software, which looks very useful for this purpose, though the lack of a northerly view might still be a problem. In addition, I hope the ultimate goal of autoguiding should further enhance tracking accuracy even without perfect polar alignment – we shall see.

The second problem initially encountered was achieving an image when using the William Optics field flattener / focal reducer. Try as I may, I could not get an image with the William Optics GT81 + field flattener + camera combination and after a few evenings trying became desperate. How could it be so difficult? All this money for top-end equipment and not even a lousy image, let alone a good picture. With the help and encouragement from members of Stargazers Lounge, I had another go. This time I was more diligent with the set-up and at first using a very bright, easy to see star, was at last able to achieve a camera image and good focus using a Bahtinov mask. In a nutshell, the problem was that the point of focus is very, very critical, just a fraction of a millimetre out and the image disappears. Now I know this it’s quite easy but nobody points this out, least of all the manufacturer or retailer, who provided little to no instructions – I am learning this is also something common in the world of astronomy, which I find quite unacceptable.

So, after some weeks of trials and tribulations, the new equipment is mostly working very well and I have been able to successfully image a wide variety of objects. There’s plenty of room for improvement but I have obtained some enjoyable and often quite exciting photographs. Now for the next challenge, which has just started: computer control and autoguiding.

NGC 6960 AKA The Witch's Broom Canon 700D | 20x90 sec + darks.bias/ flats @ ISO 800

NGC 6960 AKA The Witch’s Broom
Canon 700D | 20×90 sec + darks.bias/ flats @ ISO 800

With DSLR or CCD / webcam imaging, processing is at least equally important as the original image capture. In the later part of the year I have therefore also started to tackle this dark art. Whilst compilation software such as Deep Sky Stacker and Registax requires some understanding to set-up, it is with post-processing that the final image can be made or lost. As a result I am using the extra time indoors to try and master the various techniques, with mixed success.

I should also note that during this period my elder daughter, Alison, persuaded and then helped me set-up this website. It has proved a useful discipline for organising my thoughts and images. I am very grateful for her help and have surprisingly enjoyed recording my astronomy endeavours. Although intended as a personal record, I note from the underlying website provider that it has been read far-and-wide across the world – 36 countries this year – which is also gratifying. I would love to hear from anybody via the WTSM site: questions, what are you doing, comments & feedback etc?

Date	Object*	Feature / Name
July	M57	Ring Nebula
	M13	Globular Cluster
	M15	Globular Cluster
Aug	M27	Dumbbell Nebula
	M31	Andromeda Galaxy
	M11	Wild Duck Cluster
	ISS	International Space Station
	NGC 6888	Crescent Nebula
		The Sun
Sept	NGC 7000	North America Nebula
	NGC 6960	Western Veil Nebula & Witch’s Broom
	NGC 7380	Wizzard Nebula
	M31	Andromenda Galaxy
	IC 1396	Elephant’s Trunk Nebula
	M2	Globular Cluster
Oct	M45	Pleiades Open Star Cluster
	Uranus
	M33	The Pinwheel Galaxy
	NGC 6992	Eastern Veil Nebula
	NGC 6995	Bat Nebula
	M42 & M43	Great Orion Nebula
	NGC 7320	Stephen’s Quintet (Galaxies)
	NGC 7331	Deer Lick Group (Galaxies)
	NGC 7814	Spiral Galaxy
Nov	NGC 1909	Witch Head Nebula
	IC 434	Horsehead Nebula
	NGC 2024	Flame Nebula
	NGC 1973/75/77	Running Man Nebula
Dec	M1	Crab Nebula
	ISS	International Space Station
	NGC 2264	Christmas Tree Cluster & Cone Nebula etc.
	NGC 2261	Hubble’s Variable Nebula
	NGC 19818	Open Star Cluster
	NGC 2244	Rosette Nebula
	M35	Open Star Cluster
	M78	Reflection Nebula

Goals for 2015 are:

Transfer the mount to EQMOD computer control – I have already linked the equipment indoors, together with Cartes du Ciel, but have yet to use it outside live.

Upgrade camera control software – again I am already trialling Astrophotography Tool (APT) indoors, which looks good and provides lots of flexibility, though in some ways I still like the EOS Utility software, which uses more simple and therefore reliable control choices.

For astrophotography this is the Holy Grail and, if successful, should enable significantly longer exposures and thus better detail and sharper images to be achieved. At the time of upgrading my equipment in the summer I also purchased a William Optics 50 mm guidescope – all I need to do is get it working! This will require two further pieces of software: (i) Push Here Dummy or PHD, which is responsible for controlling the interaction between the guidecope and the mount, and (ii) Astro Tortilla, which undertakes a process called ‘plate solving’, whereby using actual pictures taken at the time of set-up, it then recognises the section of the sky it (the telescope) is looking at, identifies the object in the field of view and using this information ensures that the telescope (and thus camera) are pointing exactly towards the chosen object by iteratively interacting with the other guiding software. As a fan of the KISS principle, I must admit to being somewhat intimidated by all this but am assured by others that it is not so bad to use (famous last words) and once up and running, will have a major impact. We shall see!

Even at this stage, I can already see the need for additional equipment. With numerous Ha-emitting nebulae a modified DSLR camera is beginning to seem essential and probably a more powerful computer for image processing. I am sure this list will grow as the year progresses.

All-in-all, I am pleased with my progress during the past year, with a noticeable improvement since acquiring the new equipment. There have been more highs than lows and, I suppose, that’s a result in itself. It is very exciting when you first see Saturn, Jupiter or Mars and then image them but I have discovered that my metier and main enjoyment comes from DSOs, in particular nebulae. I find their very nature beguiling; beautiful to view, challenging but very rewarding to image and scientifically fascinating. I am therefore sure that in 2015 they will remain my main targets but, notwithstanding, there are many other objects worthy of attention, including in the UK a partial eclipse of the Sun in March.

Watch this space!

Orions Sword. Top to bottom: NGC 1981 Open Star Cluster, NGC 1973/75/77 Nebulae, M42 & M43 Great Orion Nebula & the binary star Hatsya. WO GT81, Canon 700D + FF | 30 x 120 secs + darks/bias/flats @ ISO 800

My picture of the year: Orions Sword. Top to bottom: NGC 1981 Open Star Cluster, NGC 1973/75/77 Nebulae, M42 & M43 Great Orion Nebula & the binary star Hatsya.
WO GT81, Canon 700D + FF | 30 x 120 secs + darks/bias/flats @ ISO 800

It’s Christmas Time

December 24, 2014 by grahamrob in Deep Sky Objects and tagged DSO Imaging, Nebulae | 4 Comments

Being that time of the year and with my new interest in astronomy, the possibility of imaging the Christmas Star seemed like a good idea. However, looking into the matter it becomes apparent that there is much controversy over what the actual object might have been: a star, a supernova, a shooting star (meteor), Venus or Jupiter etc. Furthermore, it even seems that we don’t know for sure when Jesus was born. Apparently due to an error by a Church cleric hundreds of years later, it is thought the birth could be up to 4 years later than believed and almost certainly was not on December 25^th! This is all news to me and makes a timely image of the night sky difficult but then, on a rare clear night last Friday, I turned the telescope and camera on NGC 2264 in the constellation Monoceros, or the Unicorn, itself within the Orion arm of the Milky Way Galaxy. Situated on the Celestial Equator to the east of Orion and above Canis Major, Monoceros is something of a new name to me. Considered a ‘modern’ constellation, since being discovered more recently than many others in the 17^th Century, it turns out to be abundant with many exciting objects. But at this time of the year it has to be NGC 2264 or the Christmas Tree Cluster which is most worthy of attention.

At first, whilst the images from the camera looked very promising and the ‘tree’ showed up well, it’s equally interesting partners were nowhere to be seen – notably the Cone Nebula and Fox Fur Nebula. Notwithstanding, following more aggressive processing adjustments they appeared, albeit smaller in my image than expected and very noisy. Technically, lessons arise from this: (i) whilst the William Optics GT81 is a great telescope with outstanding optics, it is a small telescope, and only the very largest features will fill the image (ii) in this case and probably more importantly, in order to achieve an acceptable signal to noise ratio, only longer exposures will work – I am currently working on this, with the goal of starting to autoguide as soon as possible in the New Year. Furthermore, the nebulosity is mostly Hydrogen Alpha (Ha) emission type, which my unmodded sensor therefore responds to poorly due to its inbuilt UV/IR filter; something else to deal with in the future.

Notwithstanding, I am still pleased with the result which in the end does show most of the main features, albeit with plenty of room for improvement; I also know how but getting there will not be easy. For obvious reasons the star of the show (no pun intended) is the Christmas Tree Cluster. The bright star at the bottom of the picture is Monocerotis 15 or S Monocerotis, which forms the tree’s ‘pot’ and is a quadruple system of four brilliant white stars. A little confusing, the view we get from earth of the ‘tree’ is upside down, so the following image has been inverted and is before post-processing, so as to make the stars that form the outline of the tree more clear.

NGC 2264 Christmas Tree Cluster - inverted to better show the 'tree' shape i.e the top is south

NGC 2264 Christmas Tree Cluster, before post-processing and inverted to show the ‘tree’ shape i.e the top is south. The large, bright star, 15 Moncerotis, marks the base of the ‘tree’.

However, the Christmas Tree Cluster is only part of NGC 2264’s glorious nature, most notable of which is probably the Cone Nebula. Located below (south) of the Christmas Tree, the Cone Nebula is a towering, triangular shaped column of cold, dark molecular hydrogen gas and dust, which appears to be flowing out from the young stars located close to the top of the cone. Some 2,200 light-years distant from Earth and 900 light-years further than the Orion Nebula, the Cone is quite small in the original picture but is in fact 60 arc seconds or 40 light-years in size!

NGC 2264, actual orientation: Cone Nebula at the bottom, Monocerotis 15 at the top with the Fox Fur Nebula to right but not clear, outline of the main stars and numbla defines the (invered) Chriostmas Tree Cluster WO G T81, Canon 700D + FF | 30 x 120 secs + darks/bias/flats @ ISO 800

NGC 2264 (actual orientation): Cone Nebula at the bottom, Monocerotis 15 now at the top, with the Fox Fur Nebula to the right but not visible. The outline of the main stars and associated nebulosity defines the (upside down) Christmas Tree Cluster – 15 Monocerotis is now at the top.
WO G T81, Canon 700D + FF | 30 x 120 secs + darks/bias/flats @ ISO 800

Map of Cone Nebula

Also included in the NGC 2264 region is the wonderfully named Fox Fur Nebula, so called as it is said to look like the head of a stole made from red fox fur. Combined with the aforementioned Ha light issue, my equipment cannot do this feature justice at the moment but, using an image from elsewhere, when viewed close-up (and you get your eye in) it is a very convincing feature.

Fox Fur Nebula

In addition to the above, NGC 2261 or Hubble’s Variable Nebula is worthy of mention. Located nearby to NGC 2264 this fan shaped nebula is illuminated by the star R Moncerotis.

NGC 2264 Christmas Tree Nebula shown by red box. Lower arrow points to the Cone Nebula, upper arrow indicates location of the Fox Fur Nebula. NGC 2261 Hubble’s Variable Nebula shown by red hexagon.

NGC 2261 Hubble’s Variable Nebula, illuminated by R Monocerotis star

Altogether there are more than seven nebulae to be found in this region of the sky, which has turned out to be something of a pleasant surprise to me and will be revisiting once I can achieve longer exposures and deal with Ha light better. The constellation of Monoceros is also itself something of a surprise, with the prospect of some other great images that deserve further attention in the New Year – can’t wait for Christmas to finish.

Sunset at Fairvale Observatory on the evening before the Winter Solstice

Sunset later the same day at Fairvale Observatory, the evening before the Winter Solstice

The Horse & Flame

November 26, 2014 by grahamrob in AstroBin, Deep Sky Objects, Imaging and tagged DSO Imaging, Nebulae, Orion | 2 Comments

With the full moon early in the month and some truly awful weather, I have been unable to get out at Fairvale Observatory since October 31^st! Notwithstanding , this has been an opportunity to spend time learning more about the dark art of processing, which can sometimes be more important than image capture itself, so is hopefully time well spent. Apart from the usual assistance of Mr Google, I have purchased the excellent online ‘book’ of Jerry Lodriguss, Photoshop for Astrophotographers – which I am slowly working through, and watched the equally excellent YouTube tutorials by Doug German on the same matter. It is often said that a picture is worth a thousand words, and Doug’s tutorials are probably the easiest and most accessible way into the use of Photoshop for astrophotography – I also enjoy his dry sense of humour. Finally, I am currently trialling Russell Croman’s Gradient Exterminator, which is intended to remove the external light gradient that inevitably creeps into even the best of images; it’s early days but I think I like it – it’s tricky to use and Doug German’s video tutorial is very helpful in this regard too.

The extended absence of clear night skies for astronomy also benefits subsequent viewing as the sky has changed, in this case a lot. We have now moved on to winter skies, which are best exemplified by the constellation of Orion here in the northern hemisphere. I was initially successful in imaging the iconic Orion Nebula early in October but only by getting up very, very early. At Fairlvale Observatory it now comes into view at about 10pm and after 11pm can be imaged. With clear skies finally arriving last Sunday evening, albeit accompanied by very cold temperatures, I was finally able to get out again – this time to spend more time with Orion.

In my ignorance, what has surprised me about Orion is the extensive presence of spectacular nebulae throughout the constellation: M42 Orion Nebula, M43 De Mairan’s Nebula, NGC 1973/5/7 The Running Man nebula, M78 between Alnitak and Betelguese etc, etc. But, I had also somehow overlooked the ‘Horse & Flame’, located above the Orion Nebula nearby the lower end of Orion’s belt: Mintaka – Alnilam – Alnitak. In close proximity to Alnitak (a triple star), which with an apparent magnitude between +2.0 and +4.0 is a problem for imaging, the sky is full of spectacular nebulae – notably the Flame Nebula and the iconic Horsehead Nebula. Having latterly learnt of their presence in the same part of the sky, I had to try and image them.

The Horsehead Nebula is a cloud of interstellar dust and gas that, as a result of it’s density, appears dark against the surrounding red nebulous ‘curtains’. The resulting shape looks like, well a horse’s head and has therefore become an iconic and well known image. However, located on the other north-eastern side of Alnitak is perhaps the real star (no pun intended) of the show, the Flame Nebula – NGC 2024. A combination of dark gas and dust with glowing hydrogen gas, energised by ultraviolet light emitted from Alnitak. Such is the form of these materials that the resulting effect is that of a burning flame. I was therefore thrilled that after my enforced indoor sojourn to be able to capture the Horse and Flame (sounds like a pub I’d like to visit!) together in one beautiful picture.

The Horsehead and Flame Nebulae. The Horse is located directly below (south) the large bright star Altinak triple star which forms the eastern end of Orion's belt, about half way down the image, sticking its 'head' into the red curtain nebulosity. The Flame is just to the left (east) of Altinak. WO GT81, Canon 700D + FF | 28 x 90 secs + darks/bias/flats ISO 1,000 | Photoshop processed + Gradient Exterminator

The Horsehead and Flame Nebulae. The Horse is located directly below (south) the large bright Alnitak triple star which forms the eastern (left) end of Orion’s belt, about half way down the image, sticking its ‘head’ into the red curtain of nebulosity. The Flame is just to the left (east) of Alnitak.
WO GT81, Canon 700D + FF | 28 x 90 secs + darks/bias/flats ISO 1,600 | Photoshop processed + Gradient Exterminator

The Bat

October 29, 2014 by grahamrob in Deep Sky Objects and tagged DSO Imaging, Nebulae | 1 Comment

It’s Halloween time of the year and I don’t like it. My problem is that in the UK this used to be a minor event, treated as a bit of fun for some and ignored by most. However, it’s been given the North American makeover and pumped up as a big deal, mainly on commercial grounds. Grrrrr!

Less seasonable has been the weather, which thankfully continues to be warm and sunny with occasional clear night skies. Hooray! A great combination enhanced further by the appearance of winter astronomy objects and since last weekend’s change of clocks 1-hour backwards, darkness from early evening. What’s not to like for the astronomer? Starting at 6 pm I was therefore able to spend more than 7 hours on Monday night imaging a procession of DSOs as they approached and passed the meridian. Moreover, I achieved almost perfect alignment and for the first time was able to obtain good exposures of between 120 and 180 seconds; had I tried I suspect even longer periods could have been achieved.

First off the rank was the Veil Nebula, part of the even larger Cygnus Loop, a massive supernova remnant. Located about 1,470 light years away and between 5,000 and 8,000 years old, much of this this emission nebula is not in the visible spectrum and what is is feint and difficult to image. I have already obtained a good photograph of the Western Veil of the nebula, also known as NGC 6960 or the Witch’s Broom https://watchthisspaceman.wordpress.com/2014/10/04/the-witchs-broom/ . Now with such good conditions and my best ever alignment, I decided to turn my attention to the Eastern Limb, or NGC 6992 and NGC 6995.

Cygnus Loop (Veil Nebula) in untraviolet light. Image area of the Western Veil highlighted by red box.

Cygnus Loop (Veil Nebula) in untraviolet light. Image area of the Eastern Veil highlighted by red box.

Using the new CLS light pollution filter and 30 x 120 second exposures, the resulting image from the camera immediately showed the full extent of this magnificent object, even before processing. Post processing the feature really comes to life, with large billowing waves of nebulous ionized gas and interstellar dust. The brighter, right-hand side (northern) of NGC 6992 trails off to the left (southerly) section of NGC 6995, also known as the Bat Nebula – well it is Halloween!

Eastern Veil Nebula – NGC 6992 (right) & NGC 6995 (left).
WO GT81 + Canon 700D & FF | 29 x 120 secs + darks/bias/flats @ ISO 1,600

NGC 6995 AKA The Bat Nebula (look carefully and you’ll see him!)

The Witch’s Broom

October 4, 2014 by grahamrob in Deep Sky Objects, Imaging and tagged DSO Imaging, Nebulae | 2 Comments

With polar alignment and tracking now working quite well, I have been hunting around for potential new targets before moving on to the next challenges of computer control and auto-guiding. Within the constraints of my limited sight lines, light pollution, weather and a rapidly encroaching full moon, I decided to tackle the somewhat elusive Veil Nebula. Although the apparent magnitude of 7.0 is not unduly challenging, the delicate nature and low surface brightness of this very large ionized gas cloud can make it difficult to image.

Located in the Cygnus constellation, the Veil Nebula is a very large but feint supernova remnant about 1.400 ly from Earth that exploded between 5,000 and 8,000 years ago i.e. quite recently. The Veil Nebula, Cirrus and Filamentary Nebula usually refer to those parts that can be viewed, the rest of the feature not being in the visible spectrum; the Veil is one of the largest, brightest features in the x-ray sky. So big is the Veil that various sections are recorded as separate NGC numbers: 6960, 6992, 6995, 6974, 6979 and IC 1340.

Located close to the binary star system 52 Cygni, the classic view is of the Western Veil or NGC 6960, AKA the “Witch’s Broom”, “Finger of God or “Filamentary Nebula”, which spans across 35 light-years and I therefore set out to photograph. Following the recent success of the North America Nebula I undertook a test shot at the same settings: 90 seconds at ISO 1,600. However, the resulting picture looked excessively washed out and so changed to 90 seconds at ISO 800, which seemed to work better – though you never really know until the late stages of post-processing. Despite forecasts to the contrary, the cloud rolled in after just six shots but two hours later and still tracking, the clouds parted leaving a clear sky and just enough time to take another twenty shots.

Initial processing was not encouraging. Truth be told there’s still a lot to learn with this part of astro-imaging but, with some difficulty and courtesy of Mrs G, a good image of the Witch’s Broom was eventually teased from the data.