Forbidden Fruit

September 21, 2016 by grahamrob in Autoguiding, Deep Sky Objects, General Astronomy, Imaging, Software and tagged DSO Imaging, Guiding, Messier Objects, Nebulae, Photography | 3 Comments

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Soon after embarking on my astrophotography adventure just over two years ago it became apparent that after getting the basics right – polar & star alignment, focus, image capture etc. – the Holy Grail of imaging is increased exposures times, thereby collecting more of those elusive photons that have travelled across the Universe. The first step to achieving this goal is tracking, which since purchasing my AZ-EQ6 mount in 2015 I have been successfully improving over time, on a good day achieving 180-second exposures and from time-to-time resulting in some decent images. However, the light from DSOs is often very feint and can require much longer times, which is easier said than done.

At the same time as acquiring the aforesaid mount and a William Optics GT81 telescope I also purchased a William Optics 50mm guide scope, with which I intended to start guiding and thus push exposures above my 3-minute barrier. Despite these aspirations, through a combination of events and my unease about the apparent difficulty of guiding, the guide scope has remained unused – until now. Having recently purchased a dedicated Starlight Express Lodestar X2 guide camera, I have finally been emboldened enough to give it a try.

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 initially struggled to set up the guide scope and get the guide camera working together. In particular obtaining focus proved very difficult; like the GT81 the guide scope focus turns out to be achieved within a very short distance that is measured in fractions of millimetres, which in this case required the insertion of an extension tube.

Reminiscent of the Space Shuttle on its Boeing 747 transport plane! The William Optics 50mm guide scope + Lodestar X2 guide camera neatly mounted atop the GT81 imaging scope using the integral rings.

Thereafter the big challenge, which I had previously avoided, was to start using the very popular PDH guiding software; Push Here Dummy (PHD) is named tongue-in-cheek by its original creator Craig Stark and is an amazing but somewhat intimidating piece of software.

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The principle is simple – find a star within the FOV and use it as a fixed reference point from which to assess and then correct small tracking errors in order to achieve better tracking, which thereby maintains pinpoint accuracy and enables longer exposure times, thus avoiding trailing of the sky and the objects being imaged. Its use is regarded as something of a dark art but I have finally grasped the nettle with some success. After months of clouded skies followed by an almost fatal equipment failure (see here for more), a period of exceptionally good weather and clear skies since late August provided the ideal opportunity to get to grips with this challenge that has so far eluded me.

At first I used a couple of sessions to overcome some past problems and ensure that everything was stable and worked well for basic tracking and imaging, in particular:

Repair and improve the imaging camera’s AC/DC adapter lead;

Where possible improve all other leads and connections – once bitten …..! In this respect I have significantly re-arranged and tidied up the many power, control and camera leads, which has included the addition of right-angle USB / mini-USB camera connectors that now makes plugging-in easier and produces less strain on the connections i.e. more secure. Simple, cheap and something I should have undertaken long ago;

Revisit EQMOD-ASCOM in order to achieve more robust tracking – especially reviewing the star alignment procedures;

Fit the guide scope using the rings incorporated onto the GT81 OTA, subsequently re-balancing the equipment and improve the mount’s feet positioning.

At this point I spent a couple of nights just playing with the equipment and in particular EQMOD-ASCOM, so as to obtain the best possible alignment; having suffered an enforced absence from imaging I just wanted to have some fun again too. At the end of this process, first using SynScan for polar alignment before switching to EQMOD-ASCOM + Cartes du Ciel for star alignment, I successfully produced a good 10-star alignment model which was then saved for future use. The resulting images already showed some improvement but I still had to tackle PHD. With unusually good weather I decided to leave the final set-up outside under cover, thus preserving the settings for a shot at the aforementioned task of guiding next time. In the interim I then needed to read the operating instructions and watch numerous videos on the use of PHD.

EQMOD-ASCOM 10-point alignment model. With an obstructed view of the northern sky by my house, all points are inevitably located in the southern quadrants.

Like so much of amateur astronomy, I will forever be grateful for the time and effort given by others to help those like me pursue our hobby. The material, videos and responses to my forum queries on guiding have as usual been nothing short of outstanding and very, very helpful. It’s still been difficult to get going but without the help and support of others it would be a complete non-starter. In this respect I’d like to pay credit to SGL and the Open PHD Guiding forums.

Armed with this knowledge I have since undertaken a few sessions using PHD2 with reasonable success, achieving exposure times of 5-minutes and more. Changing conditions and different objects make it necessary to continually finesse guide settings throughout the night and between nights and it’s already obvious that there’s much more to learn. Such adjustments are not always linear or empirical in nature and will often only come from gut feel (experience).

I have chosen to use ASCOM pulse guiding, though my equipment also has ST4-ports which I had initially intended to use due to its apparent simplicity. I am unable to argue the pros and cons of each method but there seems to be an overwhelming preference for pulse. What I do understand (I think) are the greater subtleties that can be obtained with the pulse guiding technique and in particular, the co-ordination it provides with ASCOM, thereby ensuring PHD and the mount communicate with each other to provide essential directional information as well as guiding. I am still investigating the impact of various BRAIN settings but through trial-and-error have progressed since my first guiding session.

First Pass: early guiding results 30th August 2016

Getting better: most recent guiding results 12th September 2016

Calibration of PHD is frustratingly slow and it seems that even after successfully completing the RA-procedure can still fail during the subsequent DEC / backlash clearance. After calibration use of the PHD Guide Assistant can then provide more help in achieving the best settings for the given set-up and conditions, though it is also very slow. However, once completed PHD is fantastic and so far has run well during the night, even when changing objects. Furthermore, I’ve also studied and experimented with the PHD Drift Align tool and am hopeful that by using this I may soon be able to both dispense with SynScan altogether and improve polar alignment, hitherto my imagining nemesis as I cannot see Polaris from my location – a very exciting prospect – what’s not to like?

Starting a sequence of experimentation I chose a familiar but hitherto difficult DSO object to image that should benefit from longer exposures. Having by now reached late-summer / early autumn, there were a few old favourites around such as the Veil and North America nebulae but for these trials I decided to go for the low hanging fruit of M27 or Apple Core nebula AKA Dumbbell nebula.

My previous image of M27 in August 2014!

With limited success I imaged this planetary nebula in my early days of astrophotography but with its 8.0’ x 5.6’ size and apparent magnitude of +7.5, I found it difficult to obtain good detail and colour. However, even without guiding the improved set-up and alignment produced better results at 3-minutes and with +5-minute guided exposures the images immediately showed very noticeable improvement.

The images were taken on four different nights starting on 23rd August and finished on 8th September, during which time the sky was clear and the weather warm with very low humidity, though by the end seeing conditions had started to deteriorate due to the impact of the emerging 1st quarter Moon. All images have been cropped to the same size of 700 x 500 pixels or 2% of the original FOV i.e. an object size of about 0.20%! Given this very small size M27 really is at the limit of the GT81 telescope.

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Strictly speaking the images are not fully comparable as the aggregate exposure times are not equal but nonetheless I think the results demonstrate the positive impact of guiding. The final two images are guided but do show greater star distortion, particularly at 8-minutes. I suspect this may be due to the period over which the mount was left outside and would probably have benefited from some alignment tweaking before imaging re-commenced – lesson learned; the severe cropping ratio has also magnified any problems that would probably be less obvious in a larger widefield image. There’s obviously room for improvement but I’m very happy with these early results which I can hopefully now build on.

M27 Apple Core Nebula – my first and favourite guided image | William Optics GT81 + 50mm guide scope & 10-point EQMOD-ASCOM star alignment model | modded Canon 550D + field flattener & Starlight Express Lodestar X2 guide camera | 3 x 300 secs @ ISO 1,600 & full calibration, 3.3% cropped image| 30th August 2016

Unfortunately there is some downside to the longer exposures obtained from Fairvale Observatory: potentially more aircraft tracks and cloud plus more extended imaging time is unavoidable but overall it is, as expected, a major leap forwards for my astrophotography. There’s still much to learn and improve with the technique but for now I am delighted to say that after nearly two years I am at last successfully guiding – would you Adam & Eve it?

Dark Matters

September 7, 2016 by grahamrob in Deep Sky Objects, Equipment, Imaging, Universe and tagged Aquila, Dark Nebula, DSO Imaging, Einstein, Hitchhiker's Guide to the Galaxy, Photography | 2 Comments

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After some months I have just finished reading Walter Isaacson’s outstanding biography of Albert Einstein. I don’t know how the author, as far as I know a scientific layperson and writer of the equally good Steve Jobs biography, is able to pull together Einstein’s thoughts and theories in such an engaging and comprehensible manner that provides both insight and understanding into his scientific thinking, life and personality.

Besides the implications his work already has for nuclear physics and astronomy, even in the 21^st Century we are only just starting to understand and confirm concepts that were either predicted or implied by his work of uniquely pioneering theoretical physics in the early part of the last century – much of which is still difficult even to comprehend, let alone understand. In the world of astronomy two of Einstein’s predictions have only recently been shown to actually exist, with very exciting implications for our understanding of the Cosmos: gravitational lensing and earlier this year, confirmation of the presence of gravitational waves – ripples in the fabric of space-time itself!

Einstein vindicated: In the constellation of Cetus, the galaxy cluster Abell 370 abounds with evidence of gravitational lensing – imaged here in 2009 by the Hubble Space Telescope

During his early work Einstein battled with 19^th Century scientists who continued to believe in the presence of the so-called ‘aether’, as proposed by Isaac Newton in 1718 – an undefined substance that supposedly filled the void in space and was responsible for the transmission of electromagnetic and gravitational forces. Subsequently Einstein’s Special Theory of Relativity was able to explain such effects without the presence of the aether but there remained problems that were finally borne out in 1924 by Edwin Hubble’s evidence that contrary to the prediction of Einstein’s work and previous astronomical theories, the Universe was in fact expanding. However, though serious these observations did not prove to be the end for Einstein’s work, merely the beginning of even more incredible theories that have even greater and more profound implications for the Universe.

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As a geologist by training, my background is scientific and I continue to follow with interest related developments across a broad spectrum. My perception, which I think is justified by facts, is that we are again experiencing something of a quantum change in our understanding of physics at the moment. No ‘new Einstein’ has yet emerged, though Stephen Hawking perhaps comes close and there are many bright minds still struggling to understand what it all means – certainly we seem no closer to a unified theory. At the ‘very small’ scale the increase in particle types since I last studied science in the 1970s is staggering, recently culminating in confirmation of the Higgs boson at the Large Hadron Collider (LHC) in Geneva; almost certainly there’s more to come from the LHC but I’ve already lost track (no pun intended) of what makes up matter.

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In the meantime, ever since Hubble’s expanding Universe bombshell, the world of physics has struggled to provide an explanation of what’s happening, except to say that for expansion to happen 95% of the Universe must consist of stuff we don’t know about, that is arbitrarily (and misleadingly) called Dark Matter (27%) and Dark Energy (68%), which have theoretical properties of mass and energy that would explain why the Universe is expanding; I find this exciting and even amusing.

Our earliest view of the Universe – the Cosmic Microwave Background, formed some 380,000 years after Big Bang 13.8 billion years ago.

As I get older I look upon the world with increased wonder and ask all the same big questions as everyone else. I still find science itself exciting as we continue to unlock nature’s wonders but have increasingly had a suspicion that despite the incredible discoveries made by mankind, we are really only scratching the surface of what’s going on. The prospect that there is still so much we do not know also provides many possibilities for what is really happening; a consoling thought as I move towards old age! I believe it’s humbling for science that they (we) only know what 5% of what the Universe is made of. Notwithstanding, like Deep Thought’s answer to the question “what’s the meaning of life the Universe and everything?” in Hitchhiker’s Guide to the Galaxy (answer = 42), it will keep thousands of scientists, their computers and the media gainfully employed for many years to come. In the meantime, perhaps I can already help them?

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Early on in my astroimaging odyssey I discovered an interest in Deep Sky Objects, in particular nebulae. I find their very nature beautiful, as the birthplace of new stars and matter itself their science is also fascinating – as Moby puts it We Are All Made of Stars. There are numerous types of nebulae of equally diverse origin, with a complex variety of delicate forms that can be both enthralling and beguiling. Generally they are made of gases and dust that emit types of light that often cannot be properly seen with the naked eye and only captured by photographic methods using various sophisticated imaging techniques, such as modified cameras or narrow band filters; their very elusiveness is part of the attraction. I have been fortunate to photograph a number of these features and never get tired of their science and beauty. However, there are other types of nebulae that are quite different.

Whereas the ‘common’ nebula is fundamentally based on activity that results in the emission or reflection of light, their other ‘ relations’ are the result of a quite opposite process. In this case so-called dark or absorption nebulae are clouds of dense interstellar dust that obscures or scatters light from nearby objects behind, such as stars or emission and reflection nebulae, resulting in large, unusually dark patches in the sky. I’ve imaged a few of these features before, where in the case of Orion such a process has produced Barnard 33, better known as the Horsehead Nebula – a dark interstellar dust region in the shape of yes, a horse’s head. Recently I set out to image another less famous but equally exciting dark nebula.

Other than resorting to solar astronomy, the period of summer sometimes seems like something of a barren period, further compounded by short nights and the absence of astronomical darkness. Notwithstanding, look closely and there’s plenty happening and, if you’re lucky, it’s possible to work into the night enjoying the warmth of the season too; I’ve recently been able to stay out in a shorts and T-shirt until past 3.00 a.m. – compare that to January – apart from the comfort there’s also no sign of the astronomer’s enemy, dew. This year my wife has grown and strategically placed two night flowering plants close to my equipment, which on warm evenings produce pleasant aromas that waft across Fairvale Observatory whilst I’m working. What’s not to like?

Night Phlox (Zaluzianskya Capensis). Though quite this small plant produces a strong smell of violets at night.

Nicotiana Alata. This large plant produces a strong, fragrant smell.

Whilst there’s no Orion (though it has made an appearance in the east from at about 3.00 a.m. since late August) or Taurus (also rising shortly before Orion) with all their iconic features, instead the summer arm of the Milky Way passes across the sky from about 8.00 p.m. presenting numerous opportunities of its own in the early part of the night.

Aquila b142

This time my targets were Barnard 142 & 143, located just west of the star Tarazed in the Aquila Constellation. Roughly equivalent to the full Moon in size distance and some 2,000 light years away, both are dark nebulae which viewed together against the dense background of stars in the Milky Way clearly make the shape of the letter E – shown first below in inverted colour.

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Previously I’ve been too busy looking for the more conventional DSOs but at some 30 arc minutes, the E Nebula – as it is known – is another excellent imaging target for the William Optics GT81 field-of-view.

E Nebula, AKA Barnard 142-3 in the Aquila Constellation. William Optics GT81 FD & modded Canon 550D + 0.80x Field Flattener | 15 x 180 sec @ ISO 1,600 | 26th August 2016

E Nebula, Barnard 142-3 Dark nebulae

It turns out there are many such dark nebulae, so I hope to be imaging others in the future. I wonder what Einstein would have made of these and moreover, the hypothesis of Dark Matter & Energy? It seems that once again he may have foreseen such developments and their possible existence may ironically even be found to relate to the cosmological constant used in his original General Theory of Relativity.

Playing poker with the heavens

August 23, 2016 by grahamrob in Imaging, Solar system, Viewing and tagged Perseids, Perseus, Photography, Solar system | 1 Comment

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It’s that time of the year when Earth ploughs its way through the tail of comet Swift-Tuttle, resulting in a the Perseids meteor shower. The name is derived from the location of the radiant point within the constellation of Perseus and Greek mythology’s reference to the sons of Perseus. Such are the orbital paths that Earth’s encounter with the comet occurs around 11^th to 13^th of August each year and can provide an enjoyable spectacle as the meteor particles rain down through atmosphere.

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Travelling at some 37 miles-a-second, the sand-grain size particles literally burn up in the blink of an eye, with the energy created producing a bright path of the light path that very briefly shoots across the night sky, sometimes green or red coloured. Some 16-miles in size, from time-to-time the comet itself actually passes nearby to Earth during its orbit around the Sun, last time being in 1992 and the next in 2126.

Perseid ZHR 2016

Whilst the timing of our annual encounter can be predicted with good accuracy, a sight of each individual meteoroid particle is entirely down to chance. Over a period of two or three days the frequency (Zenithal Hourly Rate or ZHR) may vary from a few tens to a few hundred, depending on which section of the comet’s tail Earth is passing through. Of course, observation requires a clear sky – something that’s been notably absent here at Fairvale Observatory for some time now. Notwithstanding, this year there were three consecutive clear, dark, warm nights, which occurred shortly after a new Moon that provided excellent Perseid observing opportunities.

Viewing is a matter of lying back in a suitable garden chair looking up towards the radiant position, which starts in the north east then moves to the south during the night and just waiting. This year peak Perseids were on the evening of 11^th/12^th August between about 11pm and 1am, during which time we probably saw between 20 to 40 hits an hour; the previous and subsequent evenings were also quite good, though with slightly less hits. Such is the randomness of each meteoroid hit that in practice Perseid trails occurred all over the sky and were easy to miss if outside the peripheral vision. However, overall it was a very good and enjoyable show but probably not as good as that from the ISS.

At first this looks great but look again, it’s an aircraft trace – living next to Gatwick airport doesn’t help. The giveaway is in the next shot which shows the track continuing i.e. too long and too far for a meteoroid.

At the same time using the Canon DSLR and an ultra-wide lens, I also attempted to image the Perseid shower. On the first night using Vixen Polarie tracking, set towards the radiant position and on the second night pointing east, without tracking. Control was via an intervalometer, with camera settings at ISO 800, 20 or 14 second exposures, and 5-second shot intervals. Even with such a high incidence of meteoroid hits, obtaining a photograph was still very difficult; mostly the strikes occurred outside the field-of-vision or sometimes in the 5-second pause. In total I shot over 300 images but obtained just two Perseid hits and more than a few plane tracks! Even with good preparation and clear skies it really is a case of chance but I was nonetheless pleased to have my share of luck this time and look forwards to another opportunity this time next year, weather permitting.

Gotcha – the real thing: ISO 800 @ 20 seconds with tracking.

Only just! This time the Perseid is just sneaking out of view at the bottom of the frame: ISO 800 @ 14 seconds, without tracking.

The Eagle Has Landed

August 11, 2016 by grahamrob in Deep Sky Objects, Imaging, Software and tagged DSO Imaging, Jupiter, Mars, Nebulae, Saturn, Serpens | 5 Comments

“It is never wise to let a piece of
electronic equipment know that you are in a hurry” (Murphy’s Law)

Following months of unusually protracted cloud cover during the winter and a short, though productive imaging period that can be measured in weeks, I have been unable to carry out any astrophotography since early May, when for inexplicable reasons everything went pear-shaped! The problem started on the 9^th May and it’s taken me 3-months to solve! This and other events have therefore resulted in a noticeable paucity of WTSM activity – sorry.

After an earlier successful dry-run with the equipment in preparation for Mercury’s solar transit, a few days later at the very moment the transit started when I switched on the camera, Cartes du Ciel and EQMOD-ASCOM froze and, despite my best efforts, could not be restarted i.e. no images. With the next transits not due until 2019 and thereafter 2032, this was a missed opportunity at best but as subsequent efforts failed to rectify the problem I’ve reached moments of despair.

I have used the same equipment and software successfully for nearly two years, in particular assigning the same USB COM-ports to avoid potential conflicts; experience of others shows ASCOM can be particularly fickle with the assignment of a COM port. After some discussion via the EQMOD Yahoo forum group there was consensus that the problem was probably a software conflict or driver issue. Somehow this didn’t seem right to me given the background described but with no alternative ideas I reluctantly set out to clean up the laptop and update all relevant software and drivers: ASCOM, Cartes du Ciel, EOS Utility etc. Unfortunately there was no improvement, so I checked and checked again, including all connections and wires but with no success.

I had only queried the problem with the EQMOD Yahoo group convinced that this was where the problem existed and these were after all the experts. With by now the limited darkness of summertime nights upon us, despair setting in and my daughter’s wedding to attend to, I put everything aside for a few weeks: (a) for practical reasons, and (b) in order to restore some enthusiasm – hopefully. At this point, somewhat late in the day, I decided to post a query on Stargazers Lounge; can’t think why I didn’t try before but there you go – the experience and help on SGL has almost always been very helpful and positive.

Almost immediately ‘Smudgeball’ (AKA Neil) from Scotland responded with a similar experience that turned out to be a very small break in the DSLR mains adapter insulation. On inspection I could find no such damage to my adapter but it was worth a try, though holiday travel then delayed acquiring a replacement for another few weeks. Immediately on my return I obtained a new adapter which on testing indoors with the equipment produced a successful outcome – BINGO! Soon after I was able to get outside once again and at last undertake some astrophotography, phew. Despite my resolve and perseverance there have been times I’ve really felt like giving up completely and I am still getting over the frustration of these drawn out events.

AC/DC DSLR power adapter: How can something as basic as this cause so much disruption?

Whilst this was going on I did manage to carry out some planetary observing – with Jupiter, Mars and Saturn all around it was too good to miss. For a while I have been aware that astrophotography has been distracting me from looking at the night sky itself; it seems strange but you get so tied-up with imaging and forget to look up – I hope to avoid this trap in the future. Unfortunately the re-awakening of my observing interest only served to highlight the poor quality and range of some of my eyepieces.

After some research and another query on SGL I purchased an Explore Scientific 20mm 68^oMaxvision eyepiece, which I thought would fit well in between my existing 32mm and 6mm eyepieces. The Maxvision is very well made but like many high-end eyepieces nowadays is quite bulky. However, the eyepiece has an unusual rubber twist-up eyecup, which though ingenious limits eye relief for those, such as myself, wearing spectacles and narrows the field-of-view. As a result I exchanged the Maxvison eyepiece for Explore Scientific 5-element 20mm and 10mm 70^o eyepieces, which provide much better eye relief and is therefore more suitable for my circumstances. At this time I have not used either of these but as they are more conventional in design, with good access to the top lens for viewing, I am very hopeful they will do a good job.

Explore Scientific 20mm eyepiece – good access to the wide angle top lens element provides good eye relief and full use of 70 degree FOV

I routinely watch second-hand equipment on the SGL and UK Astronomy Buy & Sell websites, which has resulted in some timely purchases in the past, including my modded Canon 550D camera and Vixen Polarie. From experience I find it pays to know exactly what you might be looking for and what a good price might be, in order to act quickly if necessary. There is great demand for popular items such as the Polarie which tend to go very quickly. Buoyed by much positive online comments I was recently lucky to see and successfully acquire a Tele Vue 2.5x Powermate, just 3-minutes after it was posted! I’ve only had brief use so far but it’s already obvious that this is an excellent piece of kit; being parfocal vignetting is eliminated and with great optics it’s noticeably a quantum improvement on a Barlow.

Additions to the family: Explore Scientific 10mm & 20mm eyepieces and 2.5x Powermate

With the return of astronomical darkness on July 20^th and the prospect of Fairvale Observatory able to function again, I have been keen to get back out. Imaging targets are mixed at this time of the year but I’ve just managed to bag three exciting new objects. The so-called Pillars of Creation are perhaps the iconic image of modern astronomy, inevitably captured best by the Hubble telescope. These towering columns of illuminated cosmic dust are situated within M16 or Eagle Nebula, in the constellation of Serpens, which at this time of the year is located low in the southern sky, just above the ecliptic at about 25^o– not an ideal but too tantalising not to give it a try.

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At 7-arcseconds in size and +6.0 apparent magnitude, the Eagle is a decent target for the William Optics GT81. Unfortunately as it’s been some time since the last session and my old nemesis of polar alignment wasn’t too good on this occasion, which combined with its low altitude and lack of guiding was always going to be a challenge. Notwithstanding I manged to get a reasonable sequence of images that show the shape of the ‘bird’ and even the general nature of the Pillars at the centre of the nebula, though inevitably exposures were short and minor star trails are evident.

M16 The Eagle Nebula: William Optics GT81 & modded Canon 550D + FF | 15 x 180 sec @ ISO 1,600 + darks | 7th August 2016

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After all the trauma of the past few months it was a satisfying result and later that night I was able to capture two more interesting objects, more of which another time – watch this space. It’s fair to say that for now the eagle had in more than one way well and truly landed, though given the preceding difficulties and eventual solution it was more like Apollo 13 than 11!

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Summertime Blues

June 15, 2016 by grahamrob in Deep Sky Objects, General Astronomy, Imaging, Software and tagged DSO Imaging, Jupiter, Mars, Saturn, Star Clusters, Sun | Leave a comment

This year the Summer Solstice falls on 20th June at 23.34 BST, meaning the Sun will have reached its furthest point north; as a result from 22nd of May to 19th July 2014 there is a state of permanent Astronomical Twilight AKA Nautical Darkness at Fairvale Observatory. This means there is a complete lack of Astronomical Darkness for imaging, which when combined with short nights poses various problems for astronomy in general. Notwithstanding, there are benefits and other opportunities which are worth exploiting.

Annual darkness at Fairvale Observatory 2016

To turn the problem around an obvious solution at this time is viewing and imaging the Sun. However, following the initial success of testing my equipment in preparation for Mercury’s transit of the Sun on 9^th May, the actual event proved disastrous for solar imaging. I have subsequently re-checked the equipment and software set-up and the problem has continued but without any obvious reason. Popular opinion on the EQMOD Forum is that it is a software issue – drivers, EQMOD, EOS Utilities – so when time allows over the summer I will reinstall and test everything, hopefully ready for the return of astronomical darkness on 20^th July. Murphy’s Law will likely mean it’s something else but for the moment this seems to be the only way forwards, or is it backwards? Having just managed to get guiding to work, I had been looking forwards to a new imaging era but that’s astrophotography!

Although the nights are now short the temperatures have been pleasantly warm; after the long dark but cold nights of winter (and spring this year) it’s been a real pleasure to be outside in summer clothing and without the threat of condensation on the equipment. Notwithstanding, ever present cloud and inevitably the Moon has continued to thwart my efforts until recently, as I have at last just managed a couple of very enjoyable evenings.

At the moment the three major planets of Jupiter, Mars and Saturn can all be seen at various times between 10.00 pm to nearly 3.00 am, when the early morning light then becomes evident. After putting on a great show during May, Jupiter still remains high in the sky just after sunset. Mars and Saturn are at a much lower declination of between 10^oand 17^o but provide very good views in the right seeing conditions, especially Mars which with an apparent dimension of 18.6^ohas recently looked excellent, even to the naked eye.

With such opportunities I decided to try out the Skywatcher 150PL and the ZWO ASI120MC once again. It is almost two years since I used this telescope, preferring instead the superior William Optics GT81 for viewing and imaging. However, with a focal length of 1,200mm and 150mm aperture (f8) the Newtonian scope is better suited to planetary objects; this was also the first time I rigged the scope for use on the AZ-EQ6 GT mount, thus providing better control than the EQ3-2 I have previously used.

Sure enough the views of each planet were very good but also being unaccustomed to the ZWO webcam through lack of use, I failed to obtain any images! Pity but the lesson learned is that I cannot just dabble with this equipment and need to dedicate more time in the future if I am to learn how to use properly again. Nonetheless, it was fun re-acquainting myself with these planets. As an unexpected bonus the ISS also flew right over Fairvale Observatory for over 7 minutes. This time the station was noticeably brighter than previously observed, which I put down to Nautical Darkness and the relative position of the Sun that results, thus producing greater reflection and therefore better illumination of the ISS when viewed from the ground?

All-in-all after months of difficulties and inactivity it was a good night and at midnight I therefore decided to swap to the William Optics GT81 for some DSO imaging. After setting-up the scope I looked up and, as if from nowhere, broken cloud had rolled in obscuring much of the sky and putting an end to any DSO imaging. Oh well, I had had a good time before and was at least able to get to bed at a civilised time – one of the other drawbacks of summer astronomy. As luck would have it the weather was also good on the following night, probably even better than before and this time I concentrated on bagging some DSO images as the planets again marched across the sky from east to west.

As a result of the aforementioned equipment and software problems I have resorted to the trusty SynScan handset again for alignment and mount control. Impressive though EQMOD and all the other paraphernalia are, so far I have found it all to be somewhat fickle and from my personal experience often unreliable. However, after last year’s enforced astronomy hiatus following my operation and the almost farcical lack of observing conditions over winter and now spring, I’ve become a little rusty with the set-up and as a result, on this occasion encountered my old nemesis – polar alignment – to be something of a problem once again.

Amongst the types of DSO objects, I find globular star clusters to be particularly intriguing; I had not even heard of such features until taking up astronomy in 2013. Some 158 of these ancient star clusters are known to orbit around the main disc of the Milky Way. At about 11bn to 13bn years old they are very old and despite what so-called experts might say, it seems to me their origin remains something of a mystery; it’s interesting that such clusters are also associated with other galaxies.

At this time of the year a number of globular and open clusters feature across the night sky and form excellent imaging targets. First up at about 11.00pm was M5 and immediately I discovered the shortcomings of my polar alignment, further aggravated by the decision to try 4.00 minute exposures = big mistake; ironically prior test shots turned about better!

M5 globular cluster + excess trailing! WO GT81 Canon 700D + FF | 9 x 240 secs @ ISO 800 + darks | 6th June 2016

M5 test shot: 10 sec @ ISO 6,400

M5 test shot: 15 sec @ ISO 6,400

Following on from M5 shortly after midnight, M13 appears at a much higher altitude, thus helping to reduce the impact of star trails. Furthermore, as I was by now fully aware of the polar alignment error, I reduced the exposure time from 4.00 to 2.00 minutes; it helped but nonetheless could not hide the impact on the resulting images. Note to self: always ensure good polar alignment. An EQMOD – ASCOM – CdC alignment model would be much better but until I can correct the aforesaid problem it’s down to SynScan and hopefully in the interim I can return to globular clusters once more during summer.

M13 with less but still noticeable trails! | WO GT81 & Canon 700D + FF | 19 x 120 secs @ ISO 800 + darks | 7th June 2016

Before going to bed I couldn’t resist a few quick shots of an old summer favourite, M57 or the Ring Nebula, itself also very high above Fairvale Observatory by this time of night. Considering the alignment problems the image wasn’t too bad, however, the first half of 2016 has really been a case of one step forwards, two back. I hope the next 6-months will be more positive, they will inevitably be darker and colder.

M57 Ring Nebula (left of centre) + Sulafat (left) & Sheliak (right) | WO GT81 & Canon 700D + FF | 13 x 120 secs @ ISO 800 | 7th June 2016

M57 – Ring Nebula, cropped.

Talk The Talk

May 25, 2016 by grahamrob in Equipment, General Astronomy, Imaging, Software, Widefield Imaging and tagged DSO Imaging, Moon, Nebulae, Photography | Leave a comment

“He who can, does. He who cannot, teaches.” 1903, George Bernard Shaw

At the end of last year I was contacted by a member of the Aperture Club, a photography group based in Purely – Surrey, who had come across this website and asked if I could give a presentation to the club’s members on astrophotography. Ordinarily I might have rejected the request – after all what do I know about astrophotography after only 18-months – but then again why not? Once I sat down and compiled some initial thoughts it was surprising just how far I had come and learnt already, albeit with still a long way to go. In the end I agreed and decided to take a two-fold approach to the talk: (i) a basic overview of astrophotography, and (ii) in this context my personal journey so far.

TTT Cover

The final structure adopted was like this, which I hoped would be both technically and aesthetically engaging and provide some insight into the challenges for astrophotography when compared to their day-to-day terrestrial pursuits:

Types of astrophotography
Astrophotography Methods
Light
Telescopes
Imaging
Cameras
Image Capture
Processing
Post Processing

I gave my talk to the club at the end of March, which lasted about 1-hour and I believe was well received; there was a good turn-out and subsequent Q&A session – which is always a good sign. I had also been asked to compile some related tasks for the members to undertake afterwards and after a break presented a second, shorter talk on some possible assignments. Copies of the talks can be accessed via the links here:

Astro Lecture PDF

Astro Assignments PDF

I would not be so arrogant to undertake such a presentation to other astrophotographers, at least not yet, but enjoyed introducing members of the Aperture Club to my hobby. Furthermore, through compiling the presentations I benefited from the process, which required me to think and understand the subjects more thoroughly than I might otherwise have done, making me think that Shaw was wrong. Good teaching requires a good understanding of the subject, the skill to impart that knowledge to the audience and the ability to apply the knowledge. I’ve previously walked the walk and in this instance I’d like to think I was able to talk the talk – I found the experience rewarding and I hope members of The Aperture Club did too?

The Sky’s The Limit

April 22, 2016 by grahamrob in Astronomy holidays, General Astronomy, Imaging, Widefield Imaging and tagged Arizona, Moon, Orion, Photography, Utah | 2 Comments

IMG_6235 (Large)

Imaging the Milky Way is a popular objective that has so far eluded me, mainly as I suffer from bad light pollution here at Fairvale Observatory. Embarking on a trip to the Southwestern USA recently where dark skies abound, I therefore had high hopes of at last achieving this goal but alas it was not to be and will have to wait for another day.

The trip of a lifetime

As a geologist I have often visited parts of Nevada, Colorado, Utah and California but never the famous sites of the Grand Canyon, Monument Valley, Glen Canyon (Lake Powell), Bryce Canyon and Zion National Park, which this time formed the trip of a lifetime.

Alvan Clark & Sons 24″ refractor telescope at Lowell Observatory, Flagstaff, Arizona

First stop was after flying into Las Vegas was Flagstaff, home of the Lowell Observatory, where Pluto was first discovered and amongst others houses a magnificent 24-inch Alvan Clark & Sons refractor telescope built in 1895, which I hoped to use for viewing at the observatory’s nightly public sessions. Unfortunately this was not to be as the sky remained resolutely overcast throughout the evening, despite good conditions earlier in the day. Notwithstanding, the observatory is a fascinating place and still remains an important centre of modern astronomy studies; the adjacent town of Flagstaff is also home to the Department of Physics and Astronomy at the Northern Arizona University.

Final notes and paper published by Percival Lowell postulating the existence of a Planet X beyond Neptune, later confirmed by Clyde Tombaugh at Lowell Observatory in 1930 and named Pluto

About 40-miles east of Flagstaff is the site of Meteor Crater, the best preserved meteorite impact crater on Earth. Nearly one mile in diameter and over 500 feet deep, the 50,000 year old crater is very big and very impressive. There’s a lot to like about Flagstaff if you’re into astronomy!

Meteor Crater, Arizona, USA

The Holsinger Meteorite: the largest remaining fragment of the 45 metre meteorite that created Meteor Crater

Moving on to the next stop at the Grand Canyon did not disappoint but staying just outside the park the location suffered some light pollution, compounded by cloud during the evening, thus prohibiting any imaging.

The incomparable Grand Canyon by day. Whilst we stayed around for sunset, unfortunately light pollution and cloud later prevented further nightscape imaging.

As a more remote location I had always envisaged that next stop at Monument Valley would be my first real opportunity to undertake some night imaging, for which purpose I had taken along the Vixen Polarie and a tripod. In preparation I had previously studied the sky in this part of the world using Cartes du Ciel, which indicated that the Milky Way would be well positioned during my visit; being 35^o latitude and 5,000 miles west of Fairvale Observatory meant that the sky was similar to that viewed in the UK three months ago and therefore included my favourite constellation Orion. Unfortunately I had overlooked one problem and my long-time nemesis, the moon.

The night sky from Lowell Observatory on 30th March 2016 – no Moon.

10-days later: night sky from Lowell Observatory on 10th April 2016, now with the Moon!

I was in the USA from 5^th to 17^th April but for some reason had modelled the sky in Flagstaff on 30^th March. It turned out that between then and 10^th April, when I was in Monument Valley, the by now half-moon had moved into the night sky and ruled out any chance of seeing or imaging the Milky Way. Of course, even if I had correctly identified the problem beforehand there was nothing I could do about it but it was still frustrating. Notwithstanding, it was a clear sky and not to be defeated turned to Plan-B, which instead took advantage of the moon’s position and in my opinion turned out quite well.

Monument Valley by Day: left to right – West Mitten, East Mitten & Merrick Buttes

Despite the remote location at Monument Valley there was noticeable light pollution from the hotel and ancillary facilities. However, being on the ground floor it was possible to set-up adjacent to the room’s balcony looking east, which was fortunately in the building’s own shadow, thus enabling a sequence of images to be taken of the night sky set against the buttes that typify this region. UnfortunateIy I overlooked setting the Vixen Polarie to half-sidereal tracking speed, which subsequently resulted in a blurred landscape when stacked but the original subs capture the buttes in some detail, themselves illuminated by the moon’s light = result!

Monument Valley by Night; order of buttes same as above. Canon 700D + Sigma 10mm wide-angle lens | 15secs @ ISO 6,400 | 10th April 2016

Monument Valley at Night – mulitple stacked shots: Sidereal tracking results in better sky but blurred landscape. Canon 700D & 10mm Sigma wide-angle lens | 20 x 15 secs @ ISO 6,400

Three days later I was in Bryce Canyon, the location of extraordinary geological features called hoodoos, which are the result of unusual and extreme weathering of the limestone cliffs found there. The land forms consist of thousands of various sized pillars of white and red limestone, seemingly lined up like soldiers along miles of the east facing limestone cliff face. Once again I used the moon to illuminate and capture the scene, this time using half-sidereal tracking. The result is somewhat haunting in nature but shows almost as much detail into the far distance as during daytime; I still find it incredible how sensitive the camera’s sensor is in gathering available light at night when extending exposure times and / or turning up the ISO setting.

Bryce Canyon at Sunset Point by Day

Bryce Canyon at Sunset Point by Night: Canon 700D + Sigma 10mm Wide-angle lens | 15 secs @ ISO 3,200 | 13th April 2016

It is clear I have much to learn about the deceptively simple nightscape photography using the Vixen Polarie but it is equally clear that the equipment provides significant potential and I look forwards to catching the Milky Way one day when the sky is clear and the moon absent. Notwithstanding the disappointment of missing out on the Milky Way this time, in the spectacular big country of Southwestern USA the sky’s the limit and I hope to go back again one day.

Too much light pollution perhaps? Even in the Big Country of the Southwestern USA getting the right conditions for astrophotography remains a gamble!

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!

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?

Good Vibrations

February 7, 2016 by grahamrob in Deep Sky Objects, Imaging and tagged DSO Imaging, Nebulae, Perseus | 1 Comment

Ever since autumn undertaking astronomy has continued to be very difficult at Fairvale Observatory; except for some periods coincident with the full Moon, I can count on the fingers of one hand the times we’ve had clear dark skies – at this rate I’m going to need a new hobby! As a result 8^th December was the last time the observatory was in action – frustrating but what can I do? Notwithstanding, on that occasion I was able to obtain decent images of three different objects, two of which were new for me.

I live under the grey bit in the South East i.e. cloudy

Apart from persistent cloud, the winter has also been unusually wet and in general I yearn for better weather. In the absence of more desirable conditions I was at least able to image something that kind of reminds us of a better more pleasant climate, NGC 1499 or The California Nebula – so called because being like the shape state of California.

perseus

Located in the constellation of Perseus, within the Orion arm of the Milky Way some 1,500 light-years from Earth, NGC 1499 is a large emission nebula about 100 light-years long, or nearly 4^o. The HII nebula is ionized by the nearby but otherwise unrelated star of Xi Persei (Menkib) but despite its size it is difficult to view and can only be properly appreciated using long exposure imaging, preferably with an Hβ filter (486 Nm) or in my case a modded-DSLR camera and light pollution filter (450 Nm – 550 Nm & 650 – 750 Nm) worked quite well.

NGC 1499 California Nebula – Xi Persei (Menkib @ top), North down: Wo GT81 & modded Canon 550D + FF | 16 x 180 secs @ ISO 1,600 & full calibration | 8th December 2016

It was a pleasure to finally image the California Nebula, which is an ideal object for the William Optics GT81. However, being nearly 2-months since imaging NGC 1499 it is now only present during the early evening and will soon be gone from the sky altogether for another year, pointing the way towards the Spring Equinox in a few weeks and hopefully improved weather and astronomy conditions, in every sense leading to good vibrations!