Planetary Playtime

SKY Live

Starting out three years ago I inevitably began my astrophotography with the Solar System, the planets and other related bodies are after all closest to Earth but, as it turns out, are far from easy to image.  At the time using a Skywatcher 150PLS and ZWO120MC webcam, I achieved some reasonable images of Saturn, Jupiter, Mars, the Moon and later the Sun but with plenty of upside potential for improvement! Shortly thereafter having acquired my current set-up, I realised that my interest lay in DSO targets and, except for the lunar eclipse in 2015 and the odd white-light image of the Sun, have mostly ignored the Solar System, until now.  Currently no less than 7 planets are present throughout the night at the moment, the largest of which provide good viewing and imaging opportunities – planetary sky above for 11th June 2017 at 11 p.m. taken from TheSkyLive.com

From April to July there are limited DSO opportunities for my scope and camera and the only choice is to look elsewhere; the absence of astronomical darkness also doesn’t help.  This year the problem has been particularly frustrating as I’m itching to get to grips with my new ZWO 1600MM-Cool camera, which after a few hurried shots early in the year proved very exciting.  And so I’ve recently been playing around, returning to old subjects and unfamiliar equipment – first imaging the comet C/2015 V2 (Johnson) and again trying my hand again at some of the planets.

Unlike the DSLR and ZWO 1600MM-Cool CMOS camera, I the ZWO 120MC video based webcam is more suitable for the planets, which poses a whole new set of issues and the use of completely different capture and process software, in my case Firecapture for imaging and Registax for processing. Both are excellent free programmes but after three years required some re-learning.

Firecapture helps a lot when experimenting to find the best gain, gamma and exposure settings for each planet but there are still other difficult tasks to overcome, in particular planetary rotation, size, seeing conditions and my personal nemesis – focus – which after numerous attempts I have still failed to master. The truth is that even with the gas giant Jupiter, the planet appears quite small with the 81mm aperture of my Williams Optics refractor and detail is difficult to make out in order to focus when also blurred by atmospheric turbulence.  Notwithstanding, the belts and even the Great Red Spot are evident in the resulting images taken between 14th and 25th June, albeit a little fuzzy!

Webcam image data capture even over a couple of minutes is prodigious and requires significant processing capacity to handle.  I have found the aptly named Castrator software useful in this regard to cut the final AVI image down to the actual size of the planetary object, thus removing substantial areas of superfluous black sky.  Registax is equally powerful for video processing and stacking, in particular the intriguingly named Wavelets, which magically help restore detail and sharpness.

Saturn

In the case of Saturn, which at the moment is quite bright and well orientated, the problem is also size and especially seeing, in my case not helped by a 35 minute imaging window as the planet transits between two trees at the end of my garden; at least the large copper beech on the left blocked out the Moon at the same time! At this location Saturn is less than 15o above the southerly horizon and as a result seeing conditions are at best poor and usually bad.  However, I manged some blurred images that clearly show Saturn’s rings and even a little colour.  I’m now looking forwards to seeing more of the final Cassini mission images before the satellite crashes into the plant in September.

These are obviously not my best images and I already feel the need try again next year, hopefully with a more appropriate telescope (Santa has already been informed). Notwithstanding, my return to the Solar System has been fun and, in between imaging I’ve also taken time to carry out observational astronomy – something I rarely do nowadays being otherwise consumed by astroimaging paraphernalia.  DSO astrophotography is likely to remain my main interest in the future and I can’t wait to revisit old favourites later in the year with the new ZWO 1600MM-Cool camera.  In the meantime, I have renewed respect for the planetary astrophotographer’s, I’ll be back another time.

 

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The Eagle Has Landed

“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 9th 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.

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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 68o Maxvision 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 70o 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.

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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.

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

With the return of astronomical darkness on July 20th 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 25o – 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.

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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

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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.

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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 9th 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 20th 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 10o   and 17o but provide very good views in the right seeing conditions, especially Mars which with an apparent dimension of 18.6o has recently looked excellent, even to the naked eye.

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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!

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

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M5 test shot: 10 sec @ ISO 6,400

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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.

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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.

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

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M57 – Ring Nebula, cropped.

By Jove

As a visual and photographic spectacle, in my opinion Jupiter comes a close second to Saturn among the planets.  The so-called ‘King of the Planets’, Jupiter is more than twice as massive as all the others combined. Notwithstanding its size, Jupiter has the shortest ‘day’ of any planet, rotating fully in just 9-hours and 50 minutes – as a result creating a significant equatorial bulge that measures 88,760 miles in diameter and 83,082 miles from pole-to-pole.  However, as a gas giant the planet does not rotate en masse, with the outer regions moving slower than the equatorial region leading to a series of distinctive belts and zones, most notable of which is the Great Red Spot – a massive storm on the edge of the South Equatorial Belt.

Partly because of its vast size and resulting gravitational field, Jupiter is thought to have played a dominant role in shaping the present Solar System.  The planet we see today is not alone, with 67 moons so far identified, the four largest discovered by Galileo 400 years ago being easily visible from Earth.  In order of distance from Jupiter the moons of Io, Europa, Ganymede and Callisto are extremely diverse in nature – ranging from the highly volcanic Io to the frozen world of Europa, whilst Ganymede and Callisto may have sub-surface oceans and are bigger than the planet Mercury.

 

Despite being by far the largest planet in the Solar System and the fourth brightest object after the Sun, Moon and Venus, my attempts to image Jupiter and its Jovian neighbours have so far met with only mixed success.

Most people’s first view of Jupiter is likely to be through binoculars or a basic telescope, which will   show the very bright planet accompanied by a number of its Gallilean moons, depending on their orbital position i.e. when located behind the planet they will, of course, not be visible.  Having viewed Jupiter a few times like this, my first attempt to image the planet and its moons was just such a view simply using the William Optics 81mm refractor, a x2 Barlow and my Canon 700D DSLR.  Compared to Jupiter the moons are not as bright and to capture their presence it is necessary to boost either the ISO or exposure time, which then overexposes the bright planet resulting in loss of detail – in this case the distinctive coloured gas bands. Conversely, with a lower ISO or exposure this detail once again becomes apparent but some or all of the moons are then lost in the image.  The way round is to combine two sets of images taken at different camera settings, thus obtaining the best of both worlds, literally.  For the moment however this remains work in progress.

Jupiter  - overexposed but  shows all four Gallilean moons.

January 2014, Jupiter – overexposed but shows all four Gallilean moons | 1 sec @ ISO 400

 

upiter - lower exposure shows the gas belts but the moons, though there, are now very difficult to see.  1/3rd sec @ ISO 800

Jupiter – lower exposure shows the gas belts but the moons, though there, are now very difficult to see. 1/3rd sec @ ISO 800

Personally I like the wider view of Jupiter and its moons but inevitably the holy grail has to be a close-up image showing details of the planet’s characteristic gas belts, which requires the use of a CCD video, in my case a ZWO ASI 120MC camera.  Having mostly concentrated on DSO photography to-date using a DSLR, my use of the ZWO camera is limited and with mixed success.  Using this camera and the Skywatcher 150PL reflector telescope I have previously managed images of Saturn, Mars and the Moon but this time I used the William Optics refractor instead.

CCD imaging is a very different technique to DSLR and it’s fair to say that I still have much to learn. Notwithstanding, using Registax for processing I obtained some reasonable first-time Jupiter images but will need more practice to improve the detail; the quality might also be improved using WinJUPOS software during processing, which applies a de-rotational programme to the fast moving planet thus reducing blur – however, I have yet to understand let alone master this software.  Also, whilst the quality of the William Optics telescope is far superior to the Skywatcher 150PL, it is obvious that its relatively short focal length is not really adequate for good planetary imaging.

21st February 2015. Jupiter up close WO 81GT81 | ZWO 120 MC

21st February 2015. Jupiter up close
WO 81GT81 | ZWO 120 MC

So far this year Jupiter had already provided a number of different opportunities for imaging.  Between February and April the planet moved across the southern sky in all its glory, whilst more recently it moved into close conjunction with Venus at the end of June and there’s more to come.

On 26th August from our vantage point on the Earth, Jupiter will appear very close to the Sun in the sky as it passes around the far side of the solar system from the Earth.  At closest approach, Jupiter and the Sun will appear at a separation of only 0°52′, making Jupiter totally unobservable for several weeks while it is lost in the Sun’s glare.  At around the same time, Jupiter will also be at its most distant from the Earth – receding to a distance of 6.40 AU – since the two planets will lie on opposite sides of the solar system.  Over following weeks and months, Jupiter will re-emerge to the west of the Sun, gradually becoming visible for ever-longer periods in the pre-dawn sky. After around six months, it will reach opposition, when it will be visible for virtually the whole night, by which time I have hopefully mastered some new techniques for imaging this Jovian King of the Planets.