Hunting Orion

Combined +180 degrees 3+5min HaLRGB (Large)

In Greek mythology it is said that Zeus, the god of thunder, placed a giant huntsman amongst the stars as the constellation Orion.  Today it is one of the most recognizable of the 88 constellations in the night sky and certainly one of the most popular amongst astronomers.  Towards its extremities it is defined by the red supergiant star Betelgeuse at the top-left and the massive blue supergiant Rigel lower-right, divided in the centre by Orion’s so-called ‘belt’ formed by the line of bright stars from left-to-right: Alnitak, Alnilam and Mintaka.  These and the other stars that make up the constellation of Orion are of great interest to astronomers and also make an attractive widefield image with a standard camera.  But the more serious astrophotographer is mainly interested in the panoply of exciting DSOs that lie within and around Orion that I have therefore been pursuing myself since late January.

My quarry started with the Horsehead and Flame nebulae imaged in narrowband processed using the Hubble Palette technique in SHO to great effect.  Much to my surprise a spectacular period of warm weather and clear skies four weeks later then allowed me to capture the Great Orion Nebula over three nights in HaLRGB with an equally good result.  Such was the fine weather conditions that I was then able to continue over a further two nights – five consecutive nights of imaging in the UK in late February, unprecedented in my experience – with the objective now being the reflection nebula M78.

M78 is the brightest diffuse reflection nebula of a group that belongs to the Orion B molecular cloud complex but with an apparent size of 8 x 6 arc seconds it is a something of a challenging target with my equipment.  Notwithstanding, with the mono CMOS ZWO camera and the opportunity of obtaining increased integration times I considered it worth a try and was not disappointed with the outcome.

I generally like to present images in their natural orientation but this time I’ve chosen to rotate the it 90o anticlockwise, thus allowing the wider horizontal framing to better show M78 and the dramatic red Ha-light of nearby Barnard’s Loop together.   As with M42 previously, I first stacked and processed two exposure sets, short 60 second and long 300 second subs, before then combining them so as to tease out subtleties within the reflection nebula itself and provide greater control of the otherwise dominant Barnard’s Loop.  Despite my concerns about equipment and scale, I’m very pleased with the outcome of the main image (top-of-the-page), which beautifully shows off both the aforementioned objects to great effect and has even extracted some of the colour and detail of associated star clusters within and around the nebula.  Not surprisingly the cropped version of M78 itself starts to look a little noisy but is nonetheless interesting (below).

Combined crop 3+5min HaLRGB (Large)

After a very unpromising few months, the weather, Orion and my astroimaging took a surprising turn for the better from the end of January.  As a result of much longer integration times using plate solving over multiple sessions, combined with varied exposure times and more complex processing, I successfully managed to bag three classic deep sky objects of the Orion constellation – what’s not to like?

IMAGING DETAILS
Object M78 Orion reflection nebula
Constellation Orion
Distance 1,350 light-years
Size 8’ x 6’   
Apparent Magnitude +8.3
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera ZWO1600MM-Cool mono  CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool + PHD2 +  Deep Sky Stacker & Photoshop CS3
Image Location              & Orientation Centre  RA 05:47:37      DEC 00:20:59                     

Top Left = North  Bottom Left = East 

Exposures (A)    LRGB 8 x 180 sec  Ha 10 x 180sec       (Total time: 1hr 24 min.)

(B)    HaLRG 12 x 300 sec B 17 x300 sec      (Total time: 5hr 25 min.)   

  @ 139 Gain   21  Offset @ -20oC    
Calibration 10 x 180 sec & 5 x 300 sec Darks  20 x 1/4000 sec Bias  10 x  HaLRGB Flats               @ ADU 25,000
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time 25th  26th 27th February  2019 @ +19.45h  
Weather Approx. 8oC   RH 60 to 80%                  🌙  ½ waning

Eleventh Hour

HaLRGB2FINALcrop (Large)

As outlined in my last post Horseplay, it seemed like plans for imaging over the winter were going to be completely scuppered this year, with weeks of cloud cover from mid-November through to late January.  I was therefore very grateful for three clear nights at the end of January that finally enabled me to carry out my principal winter imaging project of the Horsehead and Flame nebulae in narrowband.  Notwithstanding, given the preceding bad weather and the onset of galaxy season, I reckoned that this was likely to be the end of my imaging for a while, which could not have been further from the truth as more than two months of good night skies (on-and-off) then followed.

Although by late February Orion is crossing the Meridian early in the evening, darkness is still prevalent at the same time and with the aforementioned good conditions it’s been a bonus to catch more of Orion’s objects before they finally disappear for the year.  I’ve successfully imaged some parts of Orion before with the ZWO1600MM-Cool camera but for various reasons they’ve mostly been short integration times in narrowband.  It was therefore obvious that given this unexpected opportunity, on this occasion I should attempt to image everyone’s astrophotography favourite – M42 the Orion Nebula in LRGB.

At some 1,500 light years distance, M42 is the closest large star forming nebula to Earth and always holds great promise when imaging.  I’d previously obtained some good images of the Orion Nebula with a modded-DSLR camera and more recently a few narrowband images in 2017 showed the promise of using the new ZWO CMOS mono camera.  Now with unusually good weather I wanted to try and achieve an image that really showed off M42 and its neighbours M43 and the Running Man Nebula (SH-279) in all their glory, paying particular attention to the more difficult inner structures and associated Ha nebulosity.  In order to achieve this I first imaged in HaLRGB at 180 sec exposures with Unity settings for 5½ hours and then at shorter 60 sec exposures for 1 hour over three consecutive nights.

With much longer integration times than before, careful processing and manipulation to bring the long and short exposure images together, I’m very happy with the final result, which I believe achieves most of the aforementioned objectives.  Internal structure and colour is shown to good effect but I’m especially pleased with the addition of the Ha data, which dramatically enhances those areas where present together with interstellar dust within and around the main objects; I’m already planning to add more Ha data next year to further intensify the aforesaid impact.

M42 180s Ha StretchNR (Large)

M42 Ha data

Obtaining such results at this late stage of February was completely unexpected and, I thought, would effectively mark the eleventh hour this year for Orion and the rich collection of other DSOs that are found across the winter sky.  But no, there was much more to come – watch this space!

IMAGING DETAILS
Object M42 Orion Nebula + M43 & Running Man Nebula (SH2-279) etc.
Constellation Orion
Distance 1,500 light-years
Size 65’ x 60’  or 24 light-years (M42 only)
Apparent Magnitude +4.0
 
Scope  William Optics GT81 + 0.80 x Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera ZWO1600MM-Cool mono  CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool + PHD2 +  Deep Sky Stacker & Photoshop CS3
Image Location              & Orientation Centre  RA 05:35:09      DEC -05:08:31                     

Top Right = North   Top  = North East   Bottom Left = South   Bottom = South West 

Exposures (A)    L 20 x 180 sec  R 24×180 sec  G 25 x 180  B  24 x 180sec  Ha 17 x 180sec                            (Total time: 5hr 30 minutes)

(B)    12 x 60 sec HaLRGB (Total time: 1hr)   

  @ 139 Gain   21  Offset @ -20oC    
Calibration 10 x 180 sec & 15 x 60 sec Darks  20 x 1/4000 sec Bias  10 x  HaLRGB Flats               @ ADU 25,000
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time 23rd 24th 25th February  August 2019 @ +19.40h  
Weather Approx. 7oC   RH <=75%                  🌙 ¾ to ½ waning

Howling Wolf

lunar eclipse mosaic 210119x

I have a theory that at or about the time of each full moon the night sky is almost always clear, I don’t have the data but it just seems that way most of the time.  As an astrophotographer I am more than usually aware of the full moon as it makes all except narrowband imaging impossible, when it floods the night sky with its brilliant white light.  Apart from a brief and somewhat futile attempt on 14th December – the Moon and mixed cloud curtailed imaging on that occasion – my last astronomy at Fairvale Observatory was on the 17th October, thereafter being plagued by persistent cloud and bad weather; after a promising start at Les Granges Observatory in early November no further astronomy was possible during the rest of the week due to cloud and poor weather conditions.  I’m beginning to think I need a new hobby, one that is not weather dependent at least!

Given the disappointing lack of astronomy conditions I paid little attention to the upcoming lunar eclipse on the early morning of 21st January.  However, as the day approached various weather forecasts were inevitably mixed but at least two out of five held some promise of clear skies during part of the eclipse.  I therefore started to at least undertake some preliminary planning, only to discover that much of the eclipse might be obscured by houses and tall trees to the west of my location; Plan-B was to travel to nearby Reigate Priory Park which has a decent westerly outlook closer to the horizon.

As it turned out on the 20th a clear, sunny but cold and clear day preceded a clear evening and at about 3 a.m. on the 21st shortly before the action was due to start, the sky was still clear, thankfully proving my theory correct on this occasion.  Furthermore, my concerns over obscured views turned out to be mostly unfounded, with the Moon higher in the sky than envisaged and good sightlines up until the end of totality, at which time the cloud eventually rolled in anyway.  As a result I was able to enjoy over two hours viewing and imaging time, which encompassed the entire penumbral and totality stages of the eclipse.

Having obtained excellent images of the last lunar eclipse on 28th September 2015, tracking with a DSRL and the William Optics GT81 + another static, tripod fitted DSLR and 250mm zoom lens, this time I decided to adopt a different, more mobile set-up, in case Plan-B was necessary.  In 2017 I purchased a Canon 300mm f/4 L-Series telephoto lens to use for astronomy and wildlife photography.  The Canon’s Series-L lenses are a high quality, professional line especially made for APS-C cameras such as the 700D.  With no less than 15 lens elements and a fixed focal length, the picture quality for terrestrial imaging is fantastic, further assisted by a very accurate and quite image stabilizer.

This time I mounted the lens directly onto the tripod, with the camera further back so as to provide good balance between the two components.  As the autofocus and IS functions cannot be used in a dark sky for astrophotography, focus can be tricky and a compromise is required between the aperture setting for sharpness and a low ISO for quality.  As I discovered last time, the light quality diminishes significantly whilst the eclipse progresses across the face of the Moon and the aforesaid settings need to be constantly adjusted to compensate, especially during totality.  In the end I was pleased with the outcome of imaging the so-called Super Blood Wolf Moon (see mosaic above and image below).

img_1235x

As pleasing as imaging the eclipse is, like a solar eclipse viewing is an entirely different experience.  It is a pleasure to just watch the whole phenomena play out but the dramatic changes of light also has a profound effect on both the night sky itself and, in particular, the very nature of the Moon as perceived by the naked eye. On a clear night the full moon floods the night sky with its very bright light, thereby effectively hiding all but the very brightest of stars from view.  As the penumbral stage progresses (see diagram below) for about an hour the dark night sky is slowly revealed in all its glory, it’s as if someone has pulled the curtains and a new world has appeared.

total-lunar-eclipse-jan-2019-plot

Furthermore, as the moon darkens and eventually enters totality it takes on a completely different and eerie feeling, as well as a red hue caused by Raleigh scattering.  As is often the case with astrophotography the camera sensor is able to capture much greater colour and detail than the naked eye can see, thus producing beautiful images of one of nature’s best shows.  However, to the naked eye the moon takes on a different, somewhat strange nature during totality – something of a 3D effect occurs as it seems to float in the night sky like a big red balloon – something that an image cannot ever capture, making the night time adventure more exciting and worth all the effort.

Lunar eclipses are not that rare but we now have to wait 10-years for the next one in the UK which will take place on 20th December 2029, with or without cloud!

IMAGING DETAILS
Object Lunar eclipse – Super Blood Wolf Moon
Distance <238,000 miles (30,000 miles closer than usual)
Size 31’or 1/2o  
Apparent Magnitude -12.74  @ mean full moon
 
Scope / Lens  Canon L-Series 300mm f/4
Mount Manfrotto tripod
Camera Canon 700D  
Capture & Processing Manual, Photoshop CS3- Extended
Exposures x50:  Penumbral f/8   1/125’   ISO 100     Totality f/5.6  0.80’   ISO 400    
    
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time 21st January 2019 @ approx. 03.30h  
Weather <= 1oC   RH <=95%                  🌙   Eclipse

Reflections 2018

Reflections is a summary of my astronomy and astrophotography during the past year, plus some thoughts about what might happen in going forwards.  In some ways it’s a bit of a chore to compile but as it provides me with some perspective on what I’ve achieved year-to-year, I do find it to be a worthwhile exercise.

Watch This Space (Man) started in 2015 as a personal record of my astronomy journey. Notwithstanding, the blog has so far attracted 15,000 views from all over the world, including various locations in 64 countries over the past year (see map below for visitors in 2018).   I do like to hear from anybody out there – comments, questions, help or just to say hello  – and can be contacted via details in the ABOUT menu section or alternatively  just leave a comment on any item if you prefer.

 

WTSM Map 2018

 

I’m always tinkering with the website where apart from the main blog, there are also links to other astrophotographers, astronomy tools, astronomy weather, scientific papers etc.,  so even if you’re a regular visitor please take a look around from time-to-time.  Looking back I see I did not file any reports this year  under the new Astrobites section, on the other hand look out for more notable occasional image that now appears in the right-hand column under the heading Screenshot, which this year included: the Eskimo Nebula, Jupiter, the Moon & Jupiter in conjunction and Venus etc.         

Whilst there is a photo gallery of my work, for a more summary view of some of my better images there’s a FLICKR album link which is accessible from the GALLERY menu.  Following the change to mono imaging techniques in 2017, for reference each image is now accompanied by a detailed tabulation of the technical information; personally I find this information invaluable when looking at other astrophotographer’s images as a guide to settings and issues when imaging the same object myself for the first time.

Reflections Banner

Overview, Images & Goals for 2019

Since getting to grips with autoguiding in 2017, I’m pleased to say all the basic processes worked well throughout 2018, resulting in a marked improvement of individual image subs.  Long imaging times are difficult to achieve in the UK with poor skies being the norm but the successful adoption of Plate Solving this year marked a very significant breakthrough and holds great promise for ever longer integration times in the future.  Re-configuring the equipment and operating set-up in 2017 now enables operating from indoors most of the time, which apart from improving working conditions, has also made operating itself much more efficient.

I’m especially pleased that after more than 4-years astrophotography I finally manged to establish a new imaging location at the bottom of the garden this year, thereby for the first time enabling imaging of the north sky, literally opening up a new world!  For another perspective I was also fortunate to experience some excellent night skies in New Zealand, France and Cornwall during the year, which was great fun and led to some excellent images too (see 2018 CHRONICLE later in this blog).

Favourite Images

Apart from the odd DSLR shot of the night sky, my astrophotography at Fairvale Observatory in 2018 was entirely carried out with the ZWO1600MM-Cool mono CMOS sensor camera & EFW, combined with the William Optics GT81 scope, in both narrowband and broadband wavelengths.  The new camera has in every sense been a game changer and a lot more work but, in my opinion, the images this year show substantial improvement.  I also made progress using more complex processing techniques in Photoshop and improved colour and detail by combining Ha with LRGB or adding RGB and narrowband wavelengths.  With these advances I submitted a number of images to the British Astronomical Association which, I’m pleased to say, were chosen for publication on their website at various times throughout the year (see Astroimaging Record 2018 at end of blog for details).

A few of my personal favourites are shown below, in no particular order:

GR Final HaLRGB

M74 Phantom Galaxy (HaLRGB)

RGB HaOO XXX2

Rosette Nebula (HaOO) 

M13 LRGB Close-up

M13 Great Globular Cluster of Hercules (LRGB) 

Sombrero Galaxy

M104 Sombrero Galaxy (LRGB)

HHOO hlvg (Large)

Heart Nebula (HaOO)

RGB2 GxFinalX (Large)

M45 Pleiades (LRGB)

 

RECORD CARD – 2018
Goal Specifics / Results Outcome
Improve broadband and narrowband imaging

 

Improved understanding and use of the ZWO1600MM-Cool mono camera leading to better subs.  Major breakthrough with Plate Solving enabling a significant increase in image integration times and overall quality. MUCH BETTER

 

 

Improve processing Continuing to make improvements and achieving noticeably better narrowband images but with more work to do in broadband. Much greater use of various Photoshop techniques is improving detail, colours and final quality. BETTER

 

 

Expand & Improve Widefield Imaging Despite some good images of the Milky Way in the UK and NZ I barely used the Vixen Polarie tracking mount and did not make it to any dark sky sites in the UK. FAILED

 

 

I think it helps to set new goals each year, so here goes for 2019:

  • Imaging: (i) There’s lots of scope to improve imaging techniques but probably most of all I now need to improve guiding quality and then increase exposure and image integration times further. (ii) Start mosaic imaging using Plate Solving.
  • Improve processing: Despite progress, I expect this will continue to be a major challenge for some time to come. Working with Olly Penrice in France and using Steve Richards’ new book Dark Art or Magic Bullet provided lots of opportunities to learn more but I’m still considering a move to new software for pre- and post-processing – we shall see.
  • Other: (i) Widefield imaging – Since acquiring the Vixen Polarie two years ago I’ve done little more than dabble in the occasional night sky shot. Maybe just set my sights lower this year and just see what happens! (ii) Do more observing – I had been thinking of getting something bigger like a Dob for observing whilst imaging is underway but frankly now thinking just do a bit more when I can with what I’ve got.  (iii) Notwithstanding weather issues at Les Granges observatory in France, get back to at least one good dark sky site next year.

I’m very pleased to say 2018 was again very good year for astrophotography, almost certainly my best yet, which was especially defined by two positive developments that are already transforming my astrophotography and hold further promise in 2019 (I said the same last year but it’s true):

  • Starting to Plate Solve has opened up whole new possibilities, in particular: Meridian flips and multiple imaging over different nights; Mosaic imaging.
  • Fairvale Observatory South – The ability to see and image the north sky from the new location expands imaging possibilities very significantly – should have done it sooner.

You can’t ask for more than that and hope that WTSM’s Reflections 2019 will record further such success.

Watch this space!

wtsm logo

2018 CHRONICLE

Below is a quarter by quarter summary of my astronomy and astrophotography for the year 2018, followed by an imaging record.  It’s interesting but not surprising that I recorded about 50% less objects than in the previous year but, as explained, integration times have increased markedly – “never mind the width, feel the quality”!

JANUARY TO MARCH

The year started with a new perspective on astronomy – upside down!  A six week trip to New Zealand over the Christmas period produced some wonderful views of the night sky in the Southern Hemisphere. Using my basic DSLR and a GorillaPod, I was able to obtain some good images of the Milky Way, accompanied by the Large and Small Magellanic Clouds, which are unseen in the Northern Hemisphere.  New Zealand’s weather conditions and terrain also produced opportunities to see various noctilucent cloud formations, particularly on South Island (below).

IMG_9102 (Large)

Being Down Under for much of January I was unable to start astroimaging until February but it was worth the wait, which resulted in an excellent narrowband image of the Rosette Nebula with which to start the year .  From the experience and advice gained in 2017, in narrowband I now tend to stretch each Ha-OII-SII wavelength more aggressively prior to post-processing and, as a result, obtain better detail and contrast.  In this case the resulting HaOO version of the Rosette (see Favourite Images section above) was particularly good and for the first time was included on the British Astronomy Association’s website 🙂

BAA PotW

Since obtaining the ZWO1600MM-Cool mono camera narrowband imaging has been nothing less than a revelation to me.  Whilst tone mapping using the Hubble Palette produces quite spectacular and colourful results, applying the aforementioned stretching to the just the stacked Ha-wavelength subs can often result in equally exciting black and white (grey) images which show exquisite detail.  One such image taken in March was the Cone Nebula, which showed the more extensive nature of the HII-region as well as the Cone and Fox Fur Nebulae (below).

Picture saved with settings embedded.

With the passing of winter’s narrowband targets by the end of February, I moved on to broadband imaging in March.  Of all the DSO features, I am perhaps most fascinated by globular clusters but had previously obtained mixed results with a DSLR camera.  Using the CMOS based ZWO1600 mono camera, I was now able to obtain much noticeably better colour and detail of these exciting but enigmatic objects (see Favourite Images section for M13 & below for M3).

M3 LRGB Crop (Large)

I can be put-off by some of the more technical requirements associated with astrophotography and, I‘m ashamed to say, that my approach is first to – ignore it, then maybe undertake some research but do nothing, then consciously put it off again and then, when there’s absolutely no alternative – give it a try.  I am not a technophobe, quite the opposite, but often find technology and the people who design and write about it unclear to the point of making no sense sometimes or at least misleading; it seems  somewhat paradoxical that I even got onto astrophotography given these issues! Notwithstanding, when I eventually summon the courage to tackle such problems, almost always I get it to work, eventually.  Such has been the case with Plate Solving this year.

With sight lines limited by houses, hedges and tall trees to the east, south and west, I’ve hitherto had to make do with average imaging windows of up to 2-hours, either to the east or west of the Meridian and depending on the object’s declination – a lower levels  the Meridian view is itself hidden by two tall trees, obscuring up to 30o vertically and 10o either side.  Naturally these constraints limit the image integration times severely, with an inevitable impact on the quality of images, notably with higher noise, less colour and detail.  The answer of course is plate solving and during February this year I finally bit the proverbial bullet.

Since changing to the ZWO 1600MM-Cool camera I have used Astro Photography Tool (APT) for image capture and camera control, with great success.  The software is quite comprehensive and it is excellent to use, though like most software can be a little idiosyncratic in places.  This is the point where I either give-up, try other software or, as is the case with APT, turn to their excellent product Forum.  Armed with the APT manual and answers from the Forum, I soon managed to plate solve and obtain images of the Leo Triplet over two consecutive nights, which subsequently aligned and stacked well – at last!

APRIL TO JUNE

For the past year or more I’d been thinking about the possibility of moving the observatory to the end of the back garden during the spring and summer period, so as to provide a platform from which to view the northern sky, which as previously mentioned is otherwise completely obscured by my house.  The principal issue was how to operate the equipment some 30-metres away?  From the experience of others it seemed that both WiFi and Bluetooth can have big reliability issues and I am always keen to keep it simple, so for now I chose to try and use a long ethernet cable to link the operating / capture computer with a control computer indoors.

I had intended to set-up on the lawn but after I had recently extended the paving around a nearby shed in the corner of the garden, cut back some of the bushes and cleared out the shed it, was obvious that this was a preferable location; the paved base was more stable and provided a dry foundation on which to work but, furthermore, the adjacent shed could house the operating computer.  Despite successful tests indoors using an ethernet cable between the two computers and Teamviewer software, only when the equipment was set-up in position outside did I finally discover it no longer worked; I still don’t know why and the problem remains work in progress (when I can be bothered to look at it again).

Notwithstanding, it was obvious that I could instead comfortably operate the mount and camera myself from the shed and duly set about establishing what has now become Fairvale Observatory South or the Shed Observatory (see photos above); the principal observatory location by the house now becomes Fairvale Observatory North or Patio Observatory. Having established myself at the end of the garden with a not unreasonable view of the north sky over the roof of my house, I eagerly set about imaging some northern classics over the next few months.  Imaging in both narrowband and broadband I was pleased to obtain decent pictures of the Bode & Cigar galaxies and the Elephant’s Trunk Nebula before taking a break in June and July when there’s no astronomical darkness; I have imaged at this time of the year before but it’s sometimes good to take a break.

M81 B (Large)

My very first image of the northern sky M81 Bode & M82 Cigar Galaxies (LRGB)

Now I know the observatory works from this location, I plan to move there sooner in 2019 in order to spend more time with new set-up, hopefully improving on the aforementioned objects as well as trying new ones.  All-in-all the new location was a big success as well as being great fun.  Strangely I was surprised to find that the experience of guiding could be more demanding in the north sky but of course thinking about it more, as the views essentially centre on Polaris on which RA lines converge the tracking needs to be more extreme in order to move the same angular distance when compared to a southward view.  However, anxious not to upset the established settings too much, my set-up was shoddy and, as a result, guiding error was generally poor from this locality.  Next time I’ll pay more attention to this and hopefully achieve better guiding and subs.

JULY TO SEPTEMBER

After a break of nearly 8-weeks I was eager to get back to the ‘new’ observatory at the bottom of the garden.  Furthermore, much of the summer through into September was dominated by a heatwave which was accompanied by clear skies, night after night!  As a result I was able to get some very encouraging results of the Heart (see Favourite Images section above) and Soul Nebulae and finally, to my surprise, the unusual Bubble Nebula (see image below).

SHO2int3 (Large)

OCTOBER TO DECEMBER

Needless to say, once back at Fairvale Observatory North the clouds rolled in and, furthermore, suitable objects for my equipment are initially sparse at this time of the year.  Since obtaining the ZWO1600MM-Cool camera I’ve concentrated on nebulae and narrowband imaging.  Though I’ve managed a few decent LRGB images, it’s fair to say that there’s room for improvement here and therefore finished the year on M33 the Triangulum Galaxy (see below) and subsequently M45 the Pleiades.  Despite being a good size for my scope it’s become clear to me that M33 is actually a tricky object and I was not satisfied with the final image – again better guiding and longer integration next time will almost certainly help.  However, Pleiades subsequently came out well (see Favourite Images section above) but the delicate interplay of the blue star light and interstellar dust does require careful post-processing.

LRGB P2 CropXX

As it was my birthday and it’s been something of an overdue trip since first conceived in 2015, I travelled to Olly Penrice’s Les Granges Observatory at the beginning of November.  It’s a great set-up and Olly was a real pleasure to work and learn from.  As a somewhat remote location in the Hautes-Alpes region of Provence, when it’s clear the SQM values at Les Granges can exceed 22 and for the first two nights we were able to image M74 the Phantom galaxy in HaLRGB under such conditions using his TEC 140, though following some rain during the day seeing conditions were mixed on the first night.

HaLRGB mosaic (Large)

Unfortunately the clouds had followed me from the UK and for the rest of the time there we were unable to image, though it did allow me to spend some useful and enjoyable time processing with Olly.  Other than processing the M74 image and learning some new techniques, using data previously acquired by Olly and with his help, I was able to compile a wonderful 9-panel HaLRGB widefield mosaic image of the North America Nebula and surrounding region (see above).

 

Notwithstanding the mixed weather conditions, I was able to obtain my first good, face-on image of a spiral galaxy (see Favourite Images section above), which with some additional subs from Olly’s previous sessions using an 14″ ODK scope turned into a truly spectacular image (see below) of this less than popular object.

M74 ODK with TEC STARS HaLRGB Crop

 

ASTROIMAGING RECORD 2018

No Date Type Object Name
1 Jan 2018 DSLR New Zealand

 

Milky Way, Lenticular Clouds etc. 
2 09/02/18 NB NGC 2244 Rosette Nebula
       
3 11/02/18 NB NGC 2264 Cone Nebula
       
4 11/02/18 BB M44 Beehive Cluster
       
5 11/02/18 NB Abell 21 Medusa Nebula
       
6 11/02/18 BB NGC 2392 Eskimo Nebula
       
7 24/02/18 NB IC 405 Flaming Star Nebula
       
8 24/02/18 BB Moon  
       
9 19/04/18 BB M65 + M66 Leo Triplet
       
10 05/05/18 BB M3 Globular Cluster
       
11 06/05/18 BB M104 Sombrero Galaxy
       
12 06/05/18 BB M13 Globular Cluster
       
13 18/05/18 * BB M81 & M82 Bodes & Cigar Galaxies
       
14 20/05/18 NB NGC 7822 Nebula
       
15 22/05/18 NB IC 1396 Elephant’s Trunk Nebula
       
17 16/08/18 * NB IC 1805 Heart Nebula
       
18 02/09/18 NB IC 1848 Soul Nebula
       
19 03/09/18 NB NGC 7635 Bubble Nebula
       
20 09/10/18 BB M33 Triangulum Galaxy
       
21 28/10/18 BB M33 Triangulum Galaxy
       
22 2/11/18 BB M74 Phantom Galaxy
       
23 17/11/18 BB M45 Pleiades
       
24 18/11/18 BB IC 2118 Witch’s Head Nebula
       

*multiple evenings                                            Underlined = BAA published

 

Jumbo Joy

Picture saved with settings embedded.

After recently establishing Fairvale Observatory South AKA “The Shed” and dealt with some expected and unexpected problems, I was able to turn my attention to the object of my desire in this hitherto inaccessible part of the northern night sky.  With the summer solstice approaching I had originally planned on imaging this astrophotographers’ favourite later in the year but I couldn’t resist an early look.  A few nights after finishing Bodes galaxy from my new, northward looking location, I therefore swung the scope across the Meridian to the north east in order to obtain a few subs of this object just to see: (a) what it might look like with my equipment (b) bearing in mind the previous objective, to assess the best framing and (c) just for the fun of it, and was not disappointed!

RGB XXX Final (Large)The aforesaid object of interest was the Elephant’s Trunk Nebula or IC 1396, a very large emission nebula, which in narrowband shows wonderful colour and detail (HaSHO above).  IC 1396 consists of glowing gas illuminated by an open star cluster, broken up by intervening lanes of dark interstellar dust clouds.  The ‘trunk’ itself, designated IC 1396A, is the long dark area protruding from the lower edge of the image, spectacularly illuminated from behind by a bright star forming region; the image has been rotated 180o from its natural position.  Top right on the edge is the red supergiant Mu Cephei or Herschel’s Garnet Star, one of the largest and brightest known stars in the Milky Way, which in the position of the Sun would extend out to Saturn’s orbit!

HHOO (Large)

The large IC 1396 nebula will not fit my field-of-view but with some judicious framing, using the Garnet Star as a marker and helped by a few previously taken test subs, I achieved a pleasing composition with the aforesaid trunk and nearby billowing dark clouds well placed (HaOIIIOIII bicolour image above).  Whilst I am pleased with my first attempt at the Elephant’s Trunk, the colour could be better and is too noisy – a consequence of too little integration time and high gain setting.  Having had success before using similar settings for Ha-type features like the Rosette Nebula, I was a little surprised by this outcome but it just goes to show that each object is different.  Notwithstanding, the Ha version is – I think – very promising (top of the page) but obviously there is too little OIII and SII in the composite wavelength images.

RGB XXX Final Crop (Medium)

I used to live and have worked all over Africa but this is a very different type of elephant to what I have met before (the “trunk” HaSHO above).  It forms an exciting imaging subject at this time of the year, made all the more rewarding being one of my first serious attempts to image the north sky.  I hope to return to this object in a couple of months when astronomical darkness has resumed but in the meantime the Jumbo of the night sky has been a real joy on my first encounter.

Elephant Location Crop

IMAGING DETAILS
Object Elephant’s Trunk Nebula   IC 1396   
Constellation Cepheus
Distance 2,400 light-years
Size 5o or “Trunk” only approx.. 45’   
Apparent Magnitude +3.5 to +5.7
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera ZWO1600MM-Cool (mono)   CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool + PS2,  Deep Sky Stacker & Photoshop CS2
Image Location Centre  RA 21:38:37    DEC 57:30:16  
Exposures 12 x 300 sec Ha + 6 x300 sec OIII & SII  (Total time: 120 minutes)   
  @ 300 Gain   50 Offset @ -20oC    
Calibration 5 x 300sec Darks  20 x 1/4000 sec Bias  10 x  Ha + OIII + SII  Flats @ ADU 25,000  
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time 22nd May 2018  @ midnight

Boreal Breakthrough

 

M81 LRGB Final HLVG

I have often written about imaging difficulties here at Fairvale Observatory, which apart from overflying aircraft from Gatwick and Heathrow airports, 24/7 helicopters from Redhill aerodrome and general light pollution, also consists of numerous sightline obstructions in the form of large trees to the east and south, high garden hedges and the complete obstruction of the north sky by my house!  I have toyed with the idea of moving onto the lawn so as to look back northwards over the house but was concerned by all the faffing about to get the equipment down and back up a flight of steps, as well as added complications with equipment control and dew problems; I concede that many do operate successfully in this way but with plenty of other problems to cope with, I like my hobby to be as easy and convenient as possible.

Last year I enjoyed working outside during the summer months – notwithstanding the lack of darkness during much of this period – and therefore over the past winter finally considered how such a garden-based set-up could be achieved, primarily for use between May and September.  The resulting Plan-A was to place three paving stones within the lawn to support the tripod and run a USB-cable back to the house for control.  However, after recently expanding a small paved area outside the shed at the end of the garden and looking at the potential sightlines from this location, it was obvious that a Plan-B set-up here could also work.  Whilst not quite as good viewing angles as the original location, there are a number of other worthwhile benefits:

  • Being off the lawn on paving it seemed likely that dew could be less of a problem;
  • Working on the paving around the mount would be more convenient and dry;
  • By clearing out the adjacent shed it could be used as a dry location from which to control the equipment.

And so early in May I set about establishing Plan-B and soon afterwards putting it to work.

Pan1 Comp (Medium)

The view from the shed looking northwards is surprisingly quite good (see above) and I don’t know why I hadn’t considered this before. There are a few large trees to the north east, a high hedge along the western boundary and of course my house is still somewhat in the way but altogether it’s not too bad and for the first time I have a clear view of Polaris, as well as a whole new plethora of imaging targets!  Whilst this direction looks directly towards south London, being on the southern slope of the Greensand Ridge the worst of the city’s glow is fortunately obscured by the hill.  Furthermore, it is ironic that my house and the hedges also provide considerable protection from the local street lights, which I’m pleased to say are now turned off after midnight anyway.

Set-up

Local equipment layout the same as previously

I cut-back some of the adjacent vegetation to improve sightlines and ran a power cable from the house to the shed otherwise it’s exactly the same set-up which was being used at the main, south looking location on the patio by the house.  I looked into WiFi-control of the equipment but from the experience of others concluded it could be unreliable and instead considered using Teamviewer software via a USB Cat-5 repeater cable from the mount / shed computer to a second computer in the house.  However, given the distance of some 30 metres I finally decided to adopt a more robust LAN Cat-6 ethernet cable for this purpose. Unfortunately whilst this had worked successfully during testing in the house, I have so far been unable to get it to work outside and for now have had to operate the equipment from inside the shed, which has nonetheless proved to be a comfortable and effective alternative.

Being lazy and cautious about changing too much about the set-up, I levelled, aligned and reset the new location data of the tripod but kept all other settings the same for now.  I realise this is not ideal but initially just wanted to experience the new location and north sky to understand what was possible within the given field-of-view and identify any obvious problems.  Fortunately a settled period of good weather allowed me to try out the new location soon thereafter.

North Sky ViewX

White area shows optimum imaging area from Fairvale Observatory South – AKA ‘The Shed’

What I hadn’t expected on first use was that slewing and tracking would become more difficult and takes noticeably longer at higher latitudes, especially approaching Polaris.  Following subsequent enquiries and with some further thought it now makes sense.  At higher latitudes near and above about 70 degrees as the lines of Longitude are closer together, it makes the RA slew rate bigger and bigger the closer you get to the North Celestial Pole.  Of course the celestial pole is not coincident with the terrestrial pole, which means that those objects within the latitude of 90o minus the observer’s latitude – in my case this equals 39o – means that all those objects above 39o will be circumpolar from my point-of-view i.e. will rotate over the year around North Celestial Pole.  This is basic astronomy but hitherto I had not considered the implications for tracking and guiding before and will need to bear it in mind when selecting targets in the future.

M81 B (Large)

I had one particular target in mind but as it was only viable much later in the night, on this occasion I chose to start imaging the north sky for the first time with Bode’s Galaxy AKA M81 and the nearby Cigar Galaxy AKA M82; for comparison using low gain, long exposure on the first night (top of the page) and high gain, short exposure (below) on the following night.  Given the target’s DEC position of 70o I soon discovered the aforesaid tracking difficulties, which resulted in the RMS guiding error varying from 3’ to 20’ and deleterious consequences for the images!

 

Whilst I’m pleased with my very first north sky images, it is obvious I’ll need to return again with better guiding and much longer integration time.  On a positive note the general set-up worked very well and the shed provided an excellent place from which to operate the control and image capture equipment.  Furthermore, despite a few restrictions the overall view of the northern night sky is good and holds much promise for future, hitherto inaccessible imaging objects.  As a result of establishing this new site I intend to name the new north looking location Fairvale Observatory South or ‘The Shed Observatory’ (see mosaic above) and the principal, south looking location by the house Fairvale Observatory North or ‘The Patio Observatory’.  Altogether this marks a major breakthrough for my astronomy and I eagerly await the return of astronomical darkness on 20th July onward.

AstroNet ResultX

IMAGING DETAILS
Objects Bode’s Galaxy M81  &  Cigar Galaxy M82     
Constellation Ursa Major
Distance M81  11.8  &  M82  11.4 -12.4 million light-years
Size M81 26.9’ x 14.1’   &    M82 11.2’ x  4.3’
Apparent Magnitude M81 +8.0  &  M82 +8.4
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera ZWO1600MM-Cool (mono)   CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool + PS2,  Deep Sky Stacker & Photoshop CS2
Image Location Centre Image-B    RA 09:55:13.46    DEC 69:21:08.36  (19/0518) 
Exposures                       

                                       

                                         

A 18/05/18   10 x 180 sec L  + 5×180 sec RGB  (Total time: 75 minutes)    @ 139 Gain   21  Offset @ -20oC

B 19/05/18   45 x 60 sec L    + 15 x 60 sec RGB  (Total time: 90 minutes)    @ 300 Gain   50  Ofsett @ -20oC    

Calibration                    

                                        

A 15 x 180sec Darks  20 x 1/4000 sec Bias  10 x Flats LRGB  @ ADU 25,000  

B 15 x 60sec Darks     20 x 1/4000 sec Bias  10 x Flats LRGB  @ ADU 25,000  

Location & Darkness Fairvale Observatory South – Redhill – Surrey – UK       Typically Bortle 5
Date & Time (A)    18th  &   (B) 19th May 2018 @ +23.45h approx.

 

 

Star Struck

 

M13 LRGB F2 CROP (Large)

Of all the things I’ve discovered since taking up astronomy, perhaps it is the presence and nature of globular clusters that has most surprised me. Bound closely together by gravity, these massive spherical collections of stars orbit the galactic core perpendicular to its plane.  In the case of the Milky Way there are 150 globular clusters but they can be much larger in other galaxies, such as M87 which has some 13,000; clusters of clusters have also now been discovered in the Universe!  Typically each cluster might contain a few thousand or tens of thousands of stars, although in some cases they can be much larger.  Omega Centauri is the largest globular cluster in the Milky Way, being 150 light-years in diameter it contains 10 million stars; though clearly visible from Earth it can only be viewed from the Southern Hemisphere, which we unfortunately did not see when in New Zealand earlier this year.

MW &amp; globs

Despite all the advances being made in cosmology, the origin of globular clusters still seems to remain quite uncertain.  Characteristically the stars are all very old, typically in the region of 8 to 12-billion years and are of low metallicity i.e. they contain a low proportion of elements other than hydrogen and helium.  At least some, such as Alpha Centauri, are thought to have condensed from dwarf galaxies and such a process may currently be taking place within the large Magellanic Cloud – which we did see in New Zealand!  In other cases it is thought that the clusters have probably originated independently and were subsequently captured by the relevant galaxies.  However, their very old age – sometimes nearly as old as the universe itself – origin and relationship to galaxies remains intriguing.  For these and many other reasons I personally find globular clusters fascinating, probably more than any other astronomical feature, amazing as they too may be.

GlobsX

Globular Clusters May 2018: M3, M13 & M92 (red circles) + Others (yellow circles)

From time-to-time I’ve tried imaging various globular clusters but have not been satisfied with the outcome.  Now using guiding, plate solving and the high-resolution ZWO1600MM-Cool camera, it was time to give it another try this spring, when some of the best clusters are present in the northern night sky.

M3 LRGB Final (Large)

First up was M3 (Final image above), the very first Messier Object to be discovered by Charles Messier himself in 1764.  Consisting of 500,000 stars, between 8 and 11-billion years old and spanning some 220 light-years, M3 is one of the largest and brightest (absolute) globular clusters associated with the Milky Way – about 300,000 times brighter than our Sun.  It is noteworthy that the cluster contains some 274 variable stars, the highest number of any clusters, as well as a relatively high number of ‘blue stragglers’ – young main-sequence stars that appear to bluer and more luminous than the other stars in the cluster and are thought to be formed through stellar interaction of the older stars.

M3 LRGB Crop (Large)

With these attributes it is not surprising that M3 is considered a popular target in astrophotography (cropped image above), likely surpassed however by M13 AKA the Great Globular Cluster in Hercules (cropped image top-of-the-page), which conveniently follows M3 in the same area of the sky about 3-hours later (together with nearby the globular cluster M92).  And so having bagged M3 it was time to turn the telescope and camera towards M13 (Main image below).  Discovered by the eponymous Edmond Hailey in 1716 (he of Hailey’s Comet), seen from Earth M13 is slightly brighter than M3 with a wide range of star colours that certainly makes for an exciting image.  At 11.65 billion years old, M13 has been around almost three times as long as the planet Earth.

M13 LRGB Final (Large)

Since starting astrophotography I like to try my hand at imaging a globular cluster at least once each year but hitherto with disappointing results.  This time I’m pleased with the outcome, especially M13 which is surely one of the most magnificent objects in our night sky; as a bonus there are also a few galaxies in the background of both the M3 and M13 images too.  It is therefore fortunate that for those of us in the higher latitudes of the northern hemisphere the Great Globular Cluster in Hercules can be seen all-year round, though is at its highest and therefore best position between May and September – thereby inaccessible for the Kiwis who are instead compensated by Alpha Centauri!  I expect to be back again next year to marvel at these amazing and enigmatic objects, if not before.

M3 Location Crop

IMAGING DETAILS
Object M3    (NGC 5272)     
Constellation Canes Venatici
Distance 33.9 million light-years
Size 18.0’ or 220 light-years     
Apparent Magnitude +6.2
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera ZWO1600MM-Cool (mono)   CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWO x 8 + ZWO LRGB & Ha- OIII-SII 7nm filters 
Capture & Processing Astro Photography Tool + PS2,  Deep Sky Stacker & Photoshop CS2
Image Location Centre  RA 13:42:23     DEC 28:22:50  
Exposures 24 x 180 sec L + 10×180 sec RGB  (Total time: 162 minutes)   
  Unity @ 139 Gain   21  Offset @ -20oC    
Calibration 10 x 180sec Darks  20 x 1/4000 sec Bias  10 x Flats LRGB  @ ADU 25,000  
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time 5th + 6th  May 2018 @ +23.00h

M13 Location Crop

IMAGING DETAILS
Object M13     (NGC 6205)
Constellation Hercules
Distance >=20,000 light-years
Size 20’  or 150 light-years
Apparent Magnitude +5.8
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera ZWO1600MM-Cool (mono)   CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool + PS2,  Deep Sky Stacker & Photoshop CS2
Image Location Centre  RA 12:39:59    DEC -11:37:20  
Exposures 20 x 180 sec L + 15×180 sec RGB  (Total time: 195 minutes)   
  @ Unity 139 Gain   21  Offset @ -20oC  USB 40 
Calibration 10 x 180sec Darks  20 x 1/4000 sec Bias  10 x Flats LRGB  @ ADU 25,000  
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time 6th + 7th + 9th May 2018 @ +00.30h  

 

Chapeau!

LRGB GxC Crop-2 (Large)

 

I always had a general interest in astronomy but was eventually sparked into action after viewing Saturn through the Thompson 26 inch refractor at Herstmonceaux observatory in 2014.  The beauty of the planet and its unique rings is captivating and like many others it remains my favourite planet to this day.  One year on and looking further afield at Joan Genebriera’s Tacande Observatory on the island of La Palma, I discovered what is now  one of my very favourite Deep Sky Objects – M104 or the Sombrero Galaxy; until recently I used the resulting picture obtained whilst at La Palma as the main banner image for this website.  Though perhaps not as spectacular as the Orion Nebula or certain spiral galaxies, the sombrero-like galaxy (with a passing resemblance of a flying saucer too), is beguiling in its own unique way and ever since then I’ve been eager to return to The Hat and image it myself from home.

Chart_1.cdc3

However, imaging the Sombrero from the UK and especially at my location just south of London is quite another matter to La Palma.  Aside from light pollution, being at 51o north compared to 28o in La Palma, M104 is considerably lower in the sky when viewed from Fairvale Observatory in Redhill; at the time of imaging in early May it was about 26o above the southern horizon.  Furthermore, my sight lines are obscured on three sides by 15-foot hedges and directly south by two 45-foot conifers – see below SE to SW view of M104 imaging track at Fairvale Observatory.

M104 Track crop

As a result, only after it emerges from behind the western edge of the aforesaid conifers can M104 (just) be imaged, as it moves along the top of the hedge for just over an hour before disappearing from view once again.  Of course this is far from ideal but with my enthusiasm for the Sombrero, a high-resolution ZWO1600M-Cool camera and newly acquired ability to plate solve, I gave it a try over three consecutive nights.

 

RGB GxC crop (Large)

 

An unbarred spiral galaxy, the hallmark of M104 is its bright bulbous centre encircled by dark dust lanes, which when viewed from Earth tilted at just 6-degrees above the equatorial plane creates the appearance of a sombrero hat (see cropped image above).  With the much higher resolution of the Hubble telescope some 2,000 globular clusters have been identified with M104, ten-times that of the Milky Way.  In 1912 the galaxy was found to be moving away from Earth at 700 miles per second, providing an early indication that the Universe was in fact expanding in all directions.

All-in-all the Sombrero galaxy is a fascinating and unusual object, though small and all-in-all a challenging imaging target, especially seen from Fairvale Observatory.  Notwithstanding, at last I am very pleased to obtain my own exciting image of the Sombrero – chapeau!

M104 Location

IMAGING DETAILS
Object Sombrero Galaxy  M104     
Constellation Virgo
Distance 29 million light-years
Size 9’ x 4’  or  50,000 light-years
Apparent Magnitude +8.0
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera ZWO1600MM-Cool (mono)   CMOS sensor
  FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool + PS2,  Deep Sky Stacker & Photoshop CS2
Image Position Centre  RA 12:39:59    DEC -11:37:20  
Exposures 25 x 180 sec L + 3x5x180 sec RGB  (Total time: 120 minutes)   
  @ 139 Gain   21  Offset @ -20oC    
Calibration 10 x 180sec Darks  20 x 1/4000 sec Bias  10 x Flats LRGB  @ ADU 25,000  
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time 5h + 6th + 7th  May 2018 @ 23.30h  approx.

 

 

Lost In Space

IMG_9267 (Large)

Night produces a very different feeling to day.  Familiar locations take on a distinct atmosphere created by the absence of light, as the darkness imbues a sense of being in another world.  With restricted sight other senses of sound, temperature and smell become more vivid.  Furthermore, as my familiarity with the night sky has improved through astronomy, I’ve felt an increasing impression of physical separation.  Just being outside at 3.0 a.m. in the morning when most others are in bed, one becomes not only more aware of the night’s unique senses but a magical feeling of Earth’s movement through space itself.

IMG_9999x (Large)

  The Milky Way & Magellanic Clouds from Slab Hut Creek, South Island, New Zealand 

When travelling I like to read and learn about the new places I visit, in order to gain insight into the people, their culture, what’s happening and what makes them tick.  For this purpose during my recent trip to New Zealand I enjoyed reading two very different but equally fascinating books:

  • Long Cloud Ride by Josie Dew, which describes Josie Dew’s epic 6,000 mile cycle journey around New Zealand, and…
  • Squashed Possums by Jonathan Tindale. ‘Written’ by a caravan (that’s right!) assisted by its occupant. Possums describes life off the beaten track in New Zealand, specifically Jon’s life in a semi-derelict caravan in the wilderness.  The experience provides an amusing but insightful description of New Zealand, New Zealanders and the impact of living in such a remote location on humankind.  Apart from the practical and physical issues, the impact is sometimes profound – for the caravan and Jon – I was particularly struck by the description of their experience of the night sky in the back country, which powerfully captures something of my own feelings of being outside on a clear night, alone in the darkness.

SQP

I put my book down, pulled not one but two jumpers on and ventured outside to look at the cloudless night sky.  Brrr! True, it was cold, freezing probably but the view was breathtaking.  The Moon was out, or at least some of it was, and the Milky Way stretched across the sky like a colossal halo embracing the planet.  The Southern Cross stood proud, forever pointing north (?).  I turned around to look at my caravan, its windows filled with light, surrounded by the stars and darkness, reminding me of a satellite.  Lost and far away, suspended in space, I imagined an astronomer observe me from afar.

I stood there a while, quietly watching and taking in the view.  I tasted the chilled air, with a sense of time winding down a gear.  The there was a palpable jolt, like a quite earthquake that left no physical impression.  There was no crack in the earth, but there had been a change nonetheless – a profound and intoxicating sensation.

For a moment, I was disconnected.  I felt strangely without form, somehow insubstantial and insignificant.  Lost, like a speck on a rock in the darkness.  At least it might have been a moment, it may well have been much longer.  Moments may have been minutes, minutes might have been hours.  Time ceased to have any meaning.

I’d stumbled across something that is not easy to express.  It was the feeling of utter isolation, of removal not just from society, but from the world and then finally being removed from my own sense of self.  And yet, something intangible was filling this void and it pushed a tickle up my spine.

The sense of isolation quickly dissipated and instead of feeling lost, I had the profound experience of being part of everything – the earth, air and stars – all of it.  I was utterly overwhelmed by this new awareness. My subconscious struggled desperately to find a cultural reference point to cling to.  David Bowman swam past, cast adrift in the final moments of 2001: Space Odyssey, calling out to Bowie’s Major Tom.

And then, as quickly as it happened, the moment passed.  I was returned to reality, with something like an elastic twang. I’d not so much been thrown but catapulted back to this small patch of damp grass on a cold night, having been in an unexplained place.  What on earth was that?  One thing I was sure of, I was desperate for a steaming hot mug of tea.

IMG_9269 (Large)

What Comes Around Goes Around

RGB HaOO XXX2

It’s nearly 4-years since I started astronomy, like so many inspired after observing Saturn through a telescope.  Not just any telescope but the 13” Astrographic Refractor at the Observatory Science Centre in Herstmonceaux.  Built in 1890 specifically to make use of the then new technique of astrophotography, the telescope was first employed as part of the worldwide Carte Du Ciel project to map the entire night sky by photography and subsequently for a crucial test of Einstein’s then new theory of General Relativity.  Soon thereafter I was to view the aforesaid planet once again with my first, newly purchased Skywatcher 150PL Newtonian telescope.  Inevitably something of a lesser view than that at Herstmonceaux it was nonetheless just as exciting, if not more so.  I was hooked!

I then attempted afocal imaging using a compact camera held up to the telescope eyepiece but with poor results, except in one respect.  By clamping the camera onto the front of the eyepiece and achieving longer exposures, nebulosity otherwise unseen with the naked eye was revealed in the resulting image, in this case Orion’s Nebula.  As crude as the image was, for me the penny had dropped and I’ve been pursuing images of the hidden beauty of the night sky ever since.

rosette map

ngc2237map

Like mariners, through astronomy I have by now become accustomed to the seasonal procession of the night sky wonders throughout the year, none more so than the Rosette Nebula.  About 100 light-years across and 5,000 light-years from Earth, the Rosette Nebula is surely one of the annual highlights for most astrophotographers?  Located just east of Orion, the Rosette is at its best between December and February, so that I was first able to image this beautiful object myself at the end of 2014.

As a very large HII region the Rosette Nebula emits light mainly at narrowband wavelengths, which produces wonderful but mainly red colours when imaged with a modded DSLR camera.  As my astrophotography and equipment have since developed, it has become a pleasure and challenge to image objects as they return each year such as the Rosette, thereby also charting my own improvements or otherwise from year-to-year.  Its size makes the Rosette an especially attractive target for smaller telescopes such my own with an 81mm aperture, which nicely fills much of the sensor of an APS-C camera.

Despite having purchased a new ZWO1600MM-Cool mono camera at the end of 2016, by the time I was ready to use it at the end of the following March, the Rosette Nebula had almost disappeared over the western horizon for another year.  Notwithstanding, in the limited time remaining I managed to capture a few Ha-OIII-SII subs, thus marking first light for the camera, which ironically resulted in one of my favourite images for 2017.  Using narrowband for the first time it was immediately possible to see the potential of the new camera when imaging this type of object.

Returning from an extended overseas trip at the end of January this year, 10-months had passed since my last encounter with the Rosette Nebula last March and I found myself with the first real opportunity to image the nebula properly with the ZWO1600MM-Cool camera.  Since last year I’d acquired more knowledge and experience with the camera, plus this time the Rosette was now in the south eastern quadrant and provided significantly more imaging time than before.

After a break of nearly two months I needed to sort out the equipment, refocus the camera and start a new alignment model in EQASCOM.  For the first time I also decided to use longer exposure times of 300 seconds, which altogether produced a good Ha+OIII Bi-Colour image (top of page – awarded BAA Picture of the Week 4th March 2018); whilst much longer exposures are used with conventional CCD sensors, such is the sensitivity of the CMOS mono sensor in the ZWO camera that 5-minute exposures provide exceptionally good quality data.  Overall the impact of longer exposure, good focus, tracking and much longer total integration time had a noticeably positive impact on noise and overall image quality, though there’s still room for improvement – there always is!

To some extent, even after a year I’m still in the experimental phase with this camera.  For most of 2017 I used a high gain setting of 300 but this time I chose the Unity gain setting of 139 and for interest also imaged at a shorter exposure of 180 seconds.  Comparison between the two settings for Ha images – Unity gain at 300 and 180 seconds – shows that for such a nebulous type of feature as the Rosette, Unity gain works very well at the longer 300 second exposure (first image below) but not 180 seconds (second image below), which is too short to collect sufficient data.

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Picture saved with settings embedded.

Notwithstanding, in the past I have found shorter exposures at Unity or less have generally been more suitable for brighter objects such as star clusters or galaxies like Andromeda.  An alternative SHO Hubble Palette image below of the Rosette Nebula at Unity gain and 300 second exposure also compares more favourably with the same image taken last year using less subs, higher gain and shorter exposure time.

Untitled-2 Crop2 (Large)When the object is right, such as the Rosette Nebula, narrowband imaging using the ZWO camera produces exceptional results.  This is evident in these recent images where it’s now possible to clearly see structural elements of the nebula, as well as the star fields located within.  Frankly I am very excited by these new images and can’t wait for next year to come around again!

Postscript: Research at Leeds University just published suggests that the Rosette Nebula is a disc but I believe my eyes and this image and many others which says otherwise!

IMAGING DETAILS
Object Rosette Nebula     NGC 2244 + 2237, 2238, 2239 & 2246   
Constellation Monoceros
Distance 5,000 light-years
Size Approx. 100 light-years or 1.3o
Apparent Magnitude +9.0
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQASCOM computer control
Guiding William Optics 50mm guide scope
  + Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera ZWO1600MM-Cool (mono)   CMOS sensor
  FOV 2.65o x 2.0o    Resolution 2.05”/pix   Max. image size 4,656 x 3,520 pix   
EFW ZWOx8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & Processing Astro Photography Tool,  Deep Sky Stacker & Photoshop CS2
Exposures 12 x 300 sec Ha, 6 x 300 sec  OIII & SII  (Total time: 120 minutes)
  @ 139 Gain  21 Offset @ -20oC  
Calibration 5 x 300 sec Darks  20 x 1/4000 sec Bias  10 x Flats Ha, OIII & SII @ ADU 25,000  
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time 9th February 2018 @ 22.00h