The Journey

A year after taking up astronomy as a hobby, at the behest of my elder daughter I started this blog in 2014.  Describing the objective and content of the blog I adopted the strapline “A personal discovery of the Universe through astronomy and astrophotography”, which could also be described as a journey.  In reality it’s been an adventure consisting of two threads: the knowledge and related science of astronomy and the challenge of astrophotography.   As we on Earth pass through space whilst at the same time rotating 360o each year around the sun our view of the night sky changes month-by-month, inevitably returning to the same perspective each 365-days.  Against this background I therefore often return to certain objects every few years hopefully armed with new astrophotography skills in pursuit of an even better image.

Following such a path I’ve already imaged M31 the Andromeda Galaxy on four separate occasions since 2015, each time enthralled by the majesty and beauty of this barred spiral galaxy.  Notwithstanding, it was clear to me that there was significant scope for improvement of the previous images with both better data and processing. Since the last attempt in October 2019 a myriad of positive developments have taken place of which perhaps three stand out: multi-star guiding, the purchase of Chroma filters and in particular the use of PixInsight image for processing – all have been game changers, so much so that reprocessing that image now also looks good – see below.

 However, whilst the said progress has already been transformative to my astrophotography during the past year, inevitabky it is imaging conditions that play the most critical role, especially in England.   Fortunately during this autumn in both October and November for once the new moon coincided with clear skies, providing no less than six nights over which I was able to obtain almost 12-hours of some of perhaps my best ever data.  Based on this I’ve been careful to apply my best new processing skills and am thankful that the final HaLRGB image has turned out very well.  In particular, the dust lanes stand out against the bright core and surrounding blue intergalactic dust and gases, which are themselves punctuated by the bright red regions rich in Ha light. 

In the blogs that accompanied previous Andromeda images I’ve often referred to the galaxy as a neighbour of the Milky Way but really we are part of the same family known as the Local Group.  Some 10-million light years in diameter, more than 30 galaxies form two collections around the two largest galaxies of Andromeda and the Milky Way.  Gravitational forces play the central role in controlling this group, especially Andromeda which is itself moving towards the Milky Way at about 70 miles per second and is destined to merge in about +/- 4 billion years; recent studies indicate that an outer halo of stars extending up to 2-billion light years from Andromeda may be in the influence of the galaxy, suggesting this event may already have started!

Thereby my personal journey of astrophotography is set to continue somewhat in parallel with that of Andromeda, which will I am sure lead to further hopefully even better images of this exciting deep sky object that is perfect for my equipment – after all we’re getting closer at the rate of 2,207,520,000 miles each year!                     

 IMAGING DETAILS
ObjectM31 the Andromeda Galaxy.
ConstellationAndromeda
Distance2.5 million light-years
Size3.2o  x 1o  or 220,000  light-years  
Apparent Magnitude+3.44
  
Scope William Optics GT81 + Focal Reducer FL 382mm  f4.72
MountSW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
GuidingWilliam Optics 50mm guide scope
 + Starlight Xpress Lodestar X2 guide camera & PHD2 guiding
CameraZWO1600M M-Cool mono  CMOS sensor
 FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFWZWO x8 EFW + Chroma LRGB & Ha OIII SII 3nm filters 
Capture & ProcessingAstro Photography Tool , Deep Sky Stacker, PixInsight 1.8.8-8, Photoshop CS3 & Topaz AI Denoise
Image Location              & OrientationOriginal image centre  RA 00:42:48      DEC 41:15:05                      Final image rotated 180o  i.e. Bottom = North + 5% crop
ExposuresL 71 x 60 sec  R17  G 20  B  27 x 300 sec  Ha 35 x 600 sec Total time: 11hr 46 minutes   
 @ 139 Gain   21  Offset @ -20oC    
CalibrationDarks 5 x 600 sec + 5 x 300 sec + 60 x 60 sec HaLRGB Flats & Dark Flats  x15 each    @ ADU 25,000
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time1st 5th 6th 8th 9th  October & 4th November 2021 @ +/-19.00h  
WeatherApprox. 14o to 5oC   RH >=65% to +85%             🌙 New Moon

Galactic Grotto

Located along the plane of the Milky Way in the Cepheus constellation is the diffuse emission nebula Sh2-155, commonly referred to as the Cave Nebula.  This widefield view shows the so-called Cave at centre of the image, critically located at the boundary of the massive Cepheus molecular cloud and the hot, young stars of the Cepheus OB-3 association which ionize the surrounding gases to great effect. 

Location of the Cave Nebula

Overall the features are very faint and even with a total integration time of nearly 40-hours for the full data-set the Cave is difficult to capture and process using the Hubble SHO palette but nonetheless has resulted in a striking final image (see top-of-the-page).  An alternative bicolour HOO cropped version (see below) perhaps shows the details of Cave itself better?

 IMAGING DETAILS
ObjectSH2-155 Cave Nebula  AKA Caldwell 9
ConstellationCepheus
Distance2,400  light-years
Size 50 x 30 arc minutes  ~70.0 light-years;  Cave Nebula ~10.0 light- years  
Apparent Magnitude+7.7
  
Scope Takahashi FSQ 106  FL 530mm  f/5  +  Moonlight Nightcrawler focuser  
MountParamount MyT
GuidingYes
CameraQSI 683-WSG8    KAF-8300 full frame CCD sensor   5.4nm pixels  
 FOV 1.94o x 1.46o   Resolution 2.1”/pix.   Image array 3326 x 2,507 pix   
ProcessingDeep Sky Stacker,  PixInsight v1.8.8-7,  Photoshop CS3, Topaz Denoise
Image Location              Centre  –  RA 22:57:37.145      DEC +62:32:54.296                      
Exposures20 Ha  30 OIII  29 SII x 1,800 secs  @ -20C Total Integration Time: 39hr 30min     
Calibration24 x 1,800 secs Darks   x200 Bias  &  x32  Flat Darks  
Location & DarknessDeep Sky West – amateur hosting facility near Rowe, New Mexico  – USA    SQM Typically >= 21.7
Date & TimeQ3  2018    

Dark Art

Somewhat tongue-in cheek, astrophotography is often referred to as something of a dark art and to be fair it sometimes seems that way, particularly when it comes to processing.  My main interests in astrophotography are Deep Sky Objects such as emission nebulae, galaxies and planetary nebula but have long aspired to capture a more elusive category that abounds throughout the Universe – dark nebula.

Popular with astrophotographers, emission nebulae consist of vast clouds of ionised gases and regions of interstellar dust which reflect light from the said gases and or from stars and stellar nurseries that lie within – depending on their make-up the results are colourful in both broadband and narrowband wavelengths.  Dark or absorption nebulae are also a type of interstellar cloud but are so dense they completely obscure and / or soak-up visible light emitted from objects behind or within, which as a result contrasts with general light flux of the Universe forming large dark regions.  Because of their darkness they are usually faint, hard to see and moreover, difficult to image, especially from locations with light pollution.

The Horsehead Nebula is a dark nebula that has formed a part of my previous images but I’ve only imaged an isolated dark nebula once before – Barnard 142-3, which for obvious reasons is also known as the E-nebula (see above & here).  Larger more complex dark nebulae require much darker skies to image than prevail at Fairvale Observatory, such as in New Mexico, USA where the Deep Sky West observatory is located and on this occasion has produced my first ‘serious’ image of a stand-alone dark nebula.

Cepheus & the aproximate location of LDN 1250 image indicated by the red square

Lynds Dark Nebula (LDN) catalogue of dark nebulae was compiled by the eponymous Beverly T. Lynds in 1962 and is based on the study of red and blue photographic prints from the National Geographic-Palomar Observatory Sky Atlas. Situated in the north close to Polaris, the constellation of Cepheus has a number of dark nebulae, of which LDN 1250 is part of a huge complex of dark nebula surrounded by dust and scattered light from the stars of Cepheus.

LDN 1250 luminance – RGB wavelengths are also strong

Imaged here in LRGB the features come out well in all wavelengths, however, such are the subtleties of the dark nebula components I found processing difficult and required plenty of ‘dark art’ techniques.  The final image at the top of the page shows to good effect the main dark nebula, togeher with widespread but less opaque nebulosity and star colours, as well as some distant galaxies lurking in the background that together has produced a satisfying and very interesting outcome.

 IMAGING DETAILS
ObjectLDN 1250 & 1251
ConstellationCepheus
Distance1,000 light years
SizeMain nebula approximately 1o  ~ 17 light-years
Apparent Magnitude–  
  
Scope Takahashi FSQ 106  FL 530mm  f/5  +  Moonlight Nightcrawler focuser  
MountParamount MyT
GuidingYes
CameraQSI 683-WSG8    KAF-8300 full frame CCD sensor   5.4nm pixels  
 FOV 1.94o x 1.46o   Resolution 2.1”/pix.   Image array 3326 x 2,507 pix   
ProcessingDeep Sky Stacker,  PixInsight v1.8.8-7,  Photoshop CS3, Topaz Denoise
Image Location &             OrientationCentre  –  RA 22:28:54.702      DEC +75:09:45.158                    
North = Up
 
Exposures23L  + 18R +  16G + 17B x 900 secs  @ -15C
Total Integration Time: 18hr 30min     
Calibration41 x 900 secs Darks   x 50 Bias  &  x16 LRGB Flats   
Location & DarknessDeep Sky West – amateur hosting facility near Rowe, New Mexico  – USA    SQM Typically >= 21.7
Date & TimeQ4  2020    

 

Rosette Nebula – Chroma First Light

The history of astrophotography will record a period of rapid innovation during the past decade, amongst which one of the stand-out developments has been that of the CMOS sensor based camera, notably the ZWO ASI1600MM-Cool (see below).  Just look at any astrophotography website such as Astrobin and it won’t take long to find an image taken with this camera such is its popularity.  It is this very camera that I was fortunate to purchase in December 2016 shortly after its release and has been the core of my astrophotography set-up ever since. 

I have generally been very happy with the results achieved with the ZWO camera, although an issue sometimes occurs when imaging large stars, so called ‘star bloating’.  There are a number of theories discussed ad nauseam online why this might occur, of which microlensing and / or diffraction seems most likely and probably relates to either – the sensor, sensor cover or filters.  Since beginning with the ZWO camera I’ve used their excellent matching EFW with LRGB and 7nm narrowband filters.  Notwithstanding, the filters are considered to be somewhat ‘low end’ by the aficionados of such things and after living with the ZWO filters for some time, at considerable cost I recently decided to upgrade to a set of Chroma 31mm filters – LRGB + 3nm narrowband.  Together with Astrodon, Chroma filters are generally considered to be the best and my expectations were therefore high.

Being unmounted I’d previously found the ZWO filters tricky to install using the small screws and fibre washers supplied.  At 3mm Chroma are physically 1mm thicker than ZWO filters and also need to be fitted in a specific direction, which is ‘letters up’ or with top of the ID letters on the side of the filter facing towards the sensor; this is disputed by the manufacturer but there’s substantial first-hand experience online that suggests otherwise.  With these issues in mind I sought out bespoke filter masks and longer M2 6mm screws to hold the thicker filters firmly in place.  The 3D printed masks from Buckeyestargazer in the USA did a great job securing the filters and are better than those from ZWO – the internal edge of the mask forms an L-shaped ledge into which the filter fits snuggly.  Ready to go, I then had to wait nearly 4-months before the clouds parted to try out these expensive pieces of glass and then it was a full moon – I often wonder if astrophotography is a good hobby to choose in the United Kingdom but it’s too late now?

Chroma filters secured with Buckeyestargazer masks and ready to go

Given the presence of the moon it therefore had to be suitable narrowband target and after three years since I’d last imaged this object it was an opportunity to have another go at NGC 2244 AKA the Rosette Nebula, though being late February there was limited time each night before the object sunk low behind trees on the western horizon; coincidentally the ZWO ASI1600MM-Cool First Light in early 2017 was also the Rosette.  Before starting serious imaging I first tried some test shots to make sure everything worked OK and immediately discovered that the change from 7nm to 3nm had a significant impact on light gathering, thus requiring greater exposure times of an unprecedented 10 minutes.  Not surprisingly this was also apparent when taking flats which increased exposure time of up to x10 longer in duration compared to the ZWO filters; conversely preliminary but limited tests on the broadband filters seem to indicate greater transparency and thus shorter exposures, time will tell if this is correct.

So was it all worth it?  I’m very pleased with the final image which was processed using the SHO Hubble Palette with PixInsight and Photoshop (see top of the page).  There are a number of significant bright stars in and around the Rosette which the Chroma filters have handled well but overall it is the more delicate tone that has been achieved which is most pleasing.  Fundamentally the 3nm filters have produced a more subtle quality to the overall image and in particular the nebulosity.  In addition, applying Hartmut Bornemann’s excellent colour calibration script AutoColor for the first time (see Visible Dark’s video tutorial here) has resulted in a soft but exciting colour palette. 

Subsequently I have focussed on the inner region of the nebula which contains the so-called ‘Carnival of Animals’ (see above), which has been cropped and reprocessed individually to show-off the ‘animals’ or Bok globules –   named after the Dutch-American astronomer Bart Bok, who in 1947 proposed that these dark nebula indicated clouds of dust undergoing gravitational collapse as part of the process of new star formation, which has since been confirmed.  In conclusion I’d therefore say that despite the obstacles, issues and long wait, on the evidence so far the addition of the Chroma filters to my set-up has been very successful – transformative in fact.  Now I wonder if they make something that removes the clouds?  

 IMAGING DETAILS
ObjectNGC 2244 + 2337 + 2238 + 2239 + 2246  AKA the Rosette Nebula
ConstellationMonoceros
Distance5,200 light-years
Size65 light-years
Apparent Magnitude9
  
Scope William Optics GT81 + Focal Reducer FL 382mm  f4.72
MountSW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
GuidingWilliam Optics 50mm guide scope
 + Starlight Xpress Lodestar X2 camera & PHD2 guiding
CameraZWO1600MM-Cool mono  CMOS sensor
 FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFWZWO EFW + Chroma Ha, OIII & SII 3nm filters 
Capture & ProcessingAstro Photography Tool + PHD2 +  Deep Sky Stacker & Photoshop CS3
Image Location              & OrientationCentre  RA 06:31:52.688      DEC 04:58:11.11                        Top = North     
Exposures12 x 600 sec  Ha & SII  11 x 600 sec OIII Total Time:  5hr 50 min   
 @ 139 Gain   21  Offset @ -20oC    
Calibration5 x 600 sec Ha + OIII + SII   Darks 20 x 1/4000 sec Bias  &  15 x  Ha + OIII + SII Flats & Dark Flats               @ ADU 25,000
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time26th 27th 28th February 2021  @ +21.15h  
WeatherApprox. <5oC   RH >=65%                  🌙 100% Full Moon

Reflections 2020

After starting astronomy in 2014, Watch This Space (Man) was launched shortly thereafter as a personal record of my then nascent astronomy journey.  Apart from the main blog about my progress or otherwise, links to other astrophotographers, astronomy tools, astronomy weather, scientific papers etc. can also be found on this website; I was suprised to see that to-date 152 items have been published on this site.

I always like to hear from others – comments, questions, help or just to say hello – and can be contacted via: graham.s.roberts@gmail.com  or just leave a comment at the end of any item if you prefer.

Vistor map 2020: In this most difficult of years for everyone, it’s especially heartening to see so much interest from all corner’s of the world and hope to see you and others again in 2021 – Clear Skies!

REFLECTIONS is a review of my astronomy and astrophotography during the past year, together with some thoughts on possible future developments.  

2020 Overview, Images & Goals for 2021

For the world 2020 was a year like no other.  Notwithstanding the obvious problems and dire consequences of Covid-19 for everyone, there have been surprising benefits for astronomy.  Although I am retired, under lockdown there was even more time available for hobbies.  Furthermore, as I live close to Gatwick and Heathrow airports + underneath numerous high altitude long-haul overflight paths, a massive reduction in air travel resulted in a very obvious improvement in seeing conditions, which was confirmed by guiding results.  Located in a Bortle 5 to 6 area I ordinarily achieve at best average RMS error guiding of 0.90” to 1.50”/pixel, guiding improved markedly during lockdown to between 0.50” to 0.75”/ pixel.  Of course such seeing conditions also resulted in better quality imaging itself and on a number of occasions I was able to achieve integration times of 10-hours or much more over a number of nights.  The result was better images but less of them and inevitably, a lot more cloud throughout the rest of the year!

Having previously got to grips with plate solving, using the new CdC planning function I intended to develop the use of mosaics this year.  However, such is the weather in the UK (see above) that it’s obvious to me that creating mosaics is probably not the best use of what imaging time we get.  Undeterred, during January I planned and shot a 15x panel mosaic of Barnard’s Loop in Ha-wavelength.  Unfortunately the unpredictable occurrence of patchy cloud invalidated some of the panels, though I was finally able to compile a 7x panel mosaic of the upper easterly section of Barnard’s Loop – see below.  Notwithstanding, there were lessons learned: (i) restrict mosaics to one or two panels and / or (ii) where wider view images are required use a wide FOV set-up rather than a large mosaic.

Most of my other objectives for 2020 turned out to be pipedreams e.g. a new observatory or perhaps a larger telescope or dual rig.  Despite this there were important developments on other fronts.

After eventually coming to the conclusion that mosaics were probably an unwise way to go considering UK conditions, it became clear that a suitable high-quality camera lens might produce similar coverage with less imaging time and hassle.  Thus also inspired by the images of others on the SGL Forum using such equipment, I set out to build a new rig based around the excellent Samyang 135 f2 lens.  This project remains work-in-progress but so far using the lens with a bespoke 3D printed rig and micro focuser made by Astrokraken and a modded DSLR, it’s apparent that this lens produces excellent widefield images in a relatively short time.

Initial Samyang 135 f2 set-up with modded DSLR

With the time and ‘opportunity’ afforded by lockdown throughout most of the year, I finally decided to do something about improving my processing, namely learning PixInsight.  Unfortunately the rumours were correct – it is a steep learning curve and altogether a less than user friendly software.  However, after many weeks of toil and expletives I’m pleased to say I can now process an entire image with PixInsight, the impact of which has been nothing less than profound.  However, whilst PixInsight is an excellent processing facility, I’ve come to the conclusion that it is often best used together with other process software where appropriate for specific tasks:

  • Deep Sky Stacker for calibration, alignment and stacking; the equivalent PixInsight process is just too complicated and time consuming;
  • Photoshop can be very helpful finessing colours and stretching (Levels & Curves);
  • Starnet++ is useful for creating starless images, which then help to get the best from processing nebula separately before re-combining with the stars;    
  • Topaz AI Denoise has been very effective and easy to use for noise reduction and sharpening at any point during the workflow.                      

This combination for processing has turned out to be something of a game changer and almost certainly was the most important astrophotography development of the year for me, which augurs well for 2021 and beyond. 

Favourite Images

Continuing with the theme of less is more, I imaged just 13 objects this year – of which three were experimental & three with a DSLR – but still with a total integration time of 80 hours (2019 17 objects & 65 hours, 2018: 25 objects & 43 hours).  Having worked through many of the astronomer’s favourites by now, images in 2020 consisted of: a new approach to old favourites, difficult / small objects for my equipment e.g. galaxies or less popular and widefield targets. 

I’m pleased to say that most of these images turned out well and it’s difficult to choose a favourite.  The so-called ‘favourites’ below therefore represent those images from this year that portray an important development in my astrophotography journey. More detailed reviews of these and all other images from 2020 can be found in specific articles that can be accessed using the links found below or via the Blog Index, located under the dropdown menu ABOUT.  

Heart Nebula: Although imaged in 2018, this version has been re-processed using mainly PixInsight, thus transforming the original SHO Hubble Palette image from something rather dull to one with warm, vibrant colours, as well as much great detail – demonstrating the significant impact of my new PixInsight based processing abilities.   

LBN 325: Numerous emission nebulae populate this small part of a very extensiveHII-Region, which forms an exciting LRGB image.  Processing was complex and difficult, in order to bring out exciting features that abound in this spectacular but less popular area of the Cygnus constellation. Integration time of 10-hours was obtained over three nights and is my first LRGB image processed using PixInsight.       

M63 Sunflower Galaxy:  At 12.6’ x 7.2’and apparent magnitude of +9.3,this small flocculent galaxy in the Canes Venatici constellation is a challenge for my equipment. However, with 8 hours 20 minutes exposure over three nights in April and careful processing, the all-important detail within the galactic disc is clear.  Topaz Denoise AI and Gigapixel software played an important role in maintaining the colour and delicate detail in this +50% cropped image.     

Taken from last year’s REFLECTIONS 2019:

“Although you never know, I don’t see any major breakthroughs in the coming year”.  Just goes to show what I know, fewer but better images were obtained in 2020:

RECORD CARD 2020

GoalSpecifics / ResultsOutcome
Improve image captureFurther Improvements in overall quality + much longer integration times + better guiding accuracy = less but better images.MUCH BETTER    
Better processingUsing PixInsight software combined with Photoshop, Starnet++ and Topaz Denoise AI has led to major processing improvements and much better final images.      MUCH MUCH BETTER  
Widefield ImagingInitial results from new imaging rig based around Samyang 135 f2 lens were very promising but there’s more to do.BETTER    

My main objectives for 2020 were largely fulfilled (see above), so what about 2021?

  • Imaging:  Other than maintaining the aforesaid improvements achieved over the past two years – guiding & longer integration times – two items that still need to be addressed are: (i) upgrade filters to remove star bloating and all round better images, (ii) improved focussing.   
  • Widefield: Complete Samyang-rig build and switch from DSLR to CMOS mono camera.  
  • Consolidate processing improvements: Whilst the move to PixInsight and other software was very successful in 2020, I’m still only scratching the surface of what’s possible.
  • Upgrade mono camera – there’s a new generation of colour CMOS cameras starting to appear, hopefully soon to be followed by their mono equivalents !

Hardly a year I and the rest of the world will want to remember, though more than ever astrophotography played a big role in providing relief from the trauma going on around us all. 

The major increase of integration times achieved and the use of PixInsight has proved transformative for my astrophotography and will justify returning to reimage some old favourites in future years.  I had often thought about upgrading my OTA to something bigger but given the lack of a permanent observatory here at Fairvale Observatory, combined with long periods of bad / cloudy weather, the penny finally dropped and I now have high hopes for the little wonder that is the Samyang 135 f2 lens when I complete its set-up in 2021.                

Looking back I have to be happy with my astrophotography in 2020 but more importantly, look forwards to an even better year which holds great promise building on the positive developments of the past 24-months.  Moreover, I hope for the sake of everyone that we will be able to deal with Covid-19 soon and return to something of a normal life once again.  These are big ambitions and I hope that WTSM’s Reflections 2021 will record such success.

Watch this space!

 

ASTROPHOTOGRAPHY INDEX OF 2020

To access each blog, click on the title required below highlighted in RED:

JANUARY & FEBRUARY – Jinxed: Barnard’s Loop Mosaic (+ NGC 1333 reflection nebula & LDN 1622 Bogeyman Nebula)

MARCH – Nice but Dim: Medusa planetary nebula / Abell 21

MARCH & APRIL – Return of the Lion: Leo Triplet M65, M66 & NGC 3628

MAY – Galactic Bloom: M63 Sunflower Galaxy

JUNE – Canine Capers: M51 Whirlpool Galaxy

AUGUST & SEPTEMBER – The Big Picture: First Light Samyang 135 f/2 NAN, Cygnus & Veil Nebula 

OCTOBER – Reach For The Sky: LBN 325 emission nebula

NOVEMBER – Swan Adventures: NGC 6914 reflection nebula

DECEMBER – Image Redux: HST re-processing – Pacman, Heart, Rosette, NAN & California Nebula

Image Redux

An astrophotography image is clearly the sum of its parts, which can broadly be defined as: Equipment – Image Capture – Processing.  Much attention and money is given to the first two items but it’s easy to overlook the importance of processing, I should know I’ve done it for years!  With time on my hands this year during Covid-19 & lockdown, I have at last turned my attention to this most critical of items to very good effect.  Hitherto I’ve used Deep Sky Stacker (DSS) for calibration & stacking, before moving to Photoshop for all other processing, which has usually produced satisfactory results.  However, I’ve often thought more might be obtained from the data by using more powerful software combined with an improvement of my overall skills.

On taking up astrophotography it’s a shock when first looking at the camera’s data, which will usually produce a dark almost featureless image, represented by a very narrow, steep image histogram – a graphical representation of the tone and light collected by the exposures.  This is because most of the image of the night sky will of course be dark, with precious few photons arriving from distant objects being photographed contained only within the said narrow histogram – the trick is to tease them out during processing in the so-called digital darkroom, thereby revealing the image within. 

In the right hands Photoshop is an excellent tool for post processing but it’s no coincidence that most accomplished astrophotographers are using PixInsight (PI), for good reason: it is dedicated to astrophotography, is very powerful, whilst at the same time being very flexible.  Unfortunately the learning curve for PixInsight is steep but from my recent experience very much worth the effort.  Metaphorically speaking, I’m in the foothills of using PixInsight but now with sufficient knowledge to process images from start to finish, I have already successfully tackled complex LRGB images LBN 325 and NGC 6194.  Subsequently I’ve turned my attention to re-processing old narrowband data, which first time round produced unsatisfactory results using Photoshop; this being as much the user as anything else.

Whilst PixInsight was the principal software for this re-processing, it was used in conjunction with Photoshop to achieve certain affects and other newly acquired dedicated software for specific tasks: Starnet++ to produce starless images and Topaz Denoise AI for noise reduction and sharpening. Using the HST palette in all cases, the workflow (see table at the end) was adapted for each image depending on the characteristics of the object.  Before (top) and after (below) images are shown beneath, together with links to the original blogs for more background and imaging information.

NGC 281 Pacman Nebula, August 2019:  Whilst the initial HaOO bicolour image looked good I struggled to do the same with the SHO version.  However, the transformation after re-processing with PI is, as they say – a whole new ballgame.  Vibrant colours have emerged from the previous somewhat gloomy image, together with detailed internal structures.  Although somewhat artistic in character, I particularly like the starless version which is shown at the top of the page.

IC 1805 Heart Nebula, August 2018:  Like Pacman the original bicolour processing was also successful but SHO much less so.  Re-processing has brought out warm colours and details around the inner edge of the heart-shaped nebulosity but it is the striking blue inner region which highlights Melotte-15 at the centre that steals the show.  Here fierce stellar forces associated with superhot, young open star clusters, model the adjacent dust clouds into features analogous to those of the Eagle Nebula’s Pillars of Creation.

NGC 2244 Rosette Nebula, February 2018: The Rosette was the most difficult data to re-process and therefore turned out to be the most satisfying.  Similar to the Heart Nebula, the rose-like dark nebulous outer region and bright inner edge frames the dramatic, somewhat translucent pale blue inner area.  Therein billowing, cloud-like blue nebulosity shows off various internal features, which include an open star cluster at the centre and the so-called Carnival of Animals marching across the lower right quadrant.  Altogether new processing has transformed this image into something rather special.        

NGC 7000 North America Nebula, August 2017:  Although very happy with the original SHO image processed using Photoshop, the revised version is not so much better but different.  Use of the SCNR function and subsequent PI and Photoshop colour adjustments have introduced greater detail overall, as well as produced more delicate colours, especially the diaphanous blue  nebulosity around the ‘Gulf of Mexico’

NGC 1499 California Nebula, October 2017:  In this case re-processing has brought out greater structure throughout the nebula and, to a lesser degree, improved the overall colour.  However, the nature of the object, limited integration time and relative lack of what is faint OIII and SII data has probably limited the final impact.    

Frankly I found PixInsight a complete pain to understand and use initially, however, with the help of online videos, tutorials and the recently published excellent Mastering PixInsight book, I believe the results more than justify the effort and speak for themselves; overall I’m very pleased with the outcome, which far exceeds my expectations.  Notwithstanding, going forwards I can’t see PixInsight being my only processing software (though it could be) but it almost certainly will now become my main choice for post processing, where necessary supplemented by Photoshop and other packages dedicated to specific tasks.  It’s a case of using the right tool for the job and the wider combination outlined provides much more flexibility, as well as producing excellent results.  All I need now are clear skies!

OUTLINE HST NARROWBAND WORKFLOW*

ACTIONCOMMENT
Alignment & StackingDeep Sky Stacker

NON-LINEAR PRE-PROCESSING
Dynamic Crop  All stacks
Dynamic Background Extraction (DBE)  Gradient removal
RGB Combination  SHO Hubble palette
Linear Fit   
Background Neutralisation   
Colour Calibration-1  
Deconvolution (sometimes)Not used here but can be if necessary
Noise ReductionUse ACDNR or Topaz DeNoise AI
Histogram TransformationNon-linear stretch

 LINEAR PROCESSING
Curves Transformation (CT)Preliminary to bring out colours but not too strong
Colour Calibration-2 
SCNRRemove Green Hue
Magenta star adjustmentIf present + use PixelMath script
Starnet++Separate Nebula & Stars  
(a) Curves Transformation & / or
(b) Colour Saturation
Colour punch Apply Range Mask to accentuate specific areas
Photoshop – selective coloursFurther specific colour adjustment
Re-combine starless & stars imagesPixelMath script + experiment with proportions  
Final adjustments where necessaryDBE + CT + ACDNR or DeNoise AI + Linear / Curves adjustment
 * PixInsight processing unless stated otherwise 

Reach For The Sky

In September I returned to the Cygnus constellation, popular for The North America and Veil Nebula at this time of the year but elsewhere often overlooked by astrophotographers.  In particular the vast HII-region that is located around the Deneb-Sadr area which contains an abundance of exciting imaging opportunities, this time my target was LBN325 which contains numerous Ha emission nebulae, a dark nebula and a supernova remnant. To capture these features at their best, I chose to shoot, process and then combine separate HaOO narrowband and RGB images for the first time.     

Integrating RGB data for better star colours and narrowband data for nebulosity turned out to be tricky but by removing the stars from the narrowband nebulosity and then processing the starless image before combining with RGB image manually eventually worked out well (see top-of-the-page image).  However, the narrowband and broadband data had respectively been taken either side of the Meridian without plate solving and unfortunately my manual alignment was on this occasion poor.  However, with careful cropping I was eventually able to able to align and combine each of the images, though at the cost of losing 25% of the overall field-of-view which did not overlap; see full size Ha-image below with interesting features along left and right edges which had to be cropped out to align the final narrowband and broadband images.

In addition to LBN325 there are a large number of other notable features (see Image Details table at the end & Nico Carver’s annotated image below – green outline delineates areas of my image).  In addition to the many Ha emission nebulae, the most noteworthy are the dark nebula Barnard 345 and a large section of the Supernova Remnant G082.2+53.  Some 100 light-years in total diameter, this OIII-rich feature is unfortunately too faint to be picked out in my image, which would require significantly more OIII data to be seen.  Looking further afield of the image the continuing richness of the adjoining area cannot be overstated, which is beautifully seen in Nico Carver’s accompanying image (Northwestern Cygnus by Nico Carver is licensed under a CC BY-SA 4.0 License) – an 8-pannel 46-hour mosaic!  I can only dream of such work but certainly hope to return to this area again when possible, in order to enjoy more of the exquisite objects that can be found across this truly exciting area of Cygnus.  But for now there’s another story about this image.

For some time I’ve known that I had to improve my processing skills and to this end purchased PixInsight software at the beginning of the year. Very few of the best astrophotographers do not use this processing software but PixInsight has a notoriously steep learning curve and no doubt like many others I gave up after a few days!  I can unequivocally say that PixInsight is by far the most user unfriendly software I’ve come across in nearly four decades; there’s no denying it’s abilities but the developers clearly gave very little thought to its users.  Nonetheless, spurred on by the need to improve my images and the ‘opportunity’ of more time that Covid-19 has provided us all recently, I returned to PixInsight a number of times over the summer and slowly made progress.

Cropped HaLRGB M101 practice image from scratch – using Pixel Math to add Ha has worked within the galaxy but unfortunately seems to have spread into other areas too!

Using my existing data for M101, I first spent many days working through the calibration and integration process, which can only be described as exhausting!  Undeterred and in an effort to speed up matters, I moved on to Batch Processing, which though helpful only partially assists the overall task of pre-processing and inevitably put PixInsight aside again in order to find renewed enthusiasm to continue.  From this initial experience I had already come to one conclusion – that I would not be using PixInsight for calibration and integration, continuing for now with Deep Sky Stacker and possibly later switching to either Astro Pixel Processor (APP) or Astro Art, both of which get good user reviews.

From the results of others it’s clear that PixInsight is a route to better images and there is no shortage of online tutorials and books but hitherto I’d not found one that worked well for me.    Online tutorials by Light Vortex Astronomy are an excellent learning aid but tricky to work with on screen and Harry’s Astro Shed video tutorials were also helpful but I needed a book on the matter to read, thumb through and casually refer to when needed.  Then I got lucky!

It was my good fortune that in May a new text by Rogelio Bernal Andreo (AKA ‘RBA’) Mastering PixInsight became first digitally available and then in September was published as a book. The work is divided into two well thought out and presented volumes:

  • A comprehensive, easy-to-follow and understand description of how to use PixInsight
  • A reference guide providing more in-depth information on specific PixInsight processes

The two volumes come as a boxed set, are well bound and illustrated and for the first time (from my point-of-view) form an accessible, easy to use and helpful text on PixInsight.  RBA deserves every success with this outstanding book(s) which I believe will transform the otherwise torrid experience of learning PixInsight.  Armed with RBA’s Mastering PixInsight, Light Vortex Astronomy online tutorials, Harry’s Astro Shed and a other online videos, I’m pleased to say that I am now at last able to use PixInsight for processing and LBN325 is my first image; I should also mention Shawn Nielsen’s excellent Visible Dark YouTube channel, which demonstrates a number of very useful techniques.

As my first attempt to use PixInsight for processing, I’m pleased with the outcome of LBN 325 but realise there’s still much more to learn and, aside from the framing error, it’s clear that even more integration time is needed to get the best of LBN325 and its companions.  Going forwards PixInsight and Photoshop both have their respective strengths and weaknesses and judicious use of various techniques from each is probably going to yield the best results.  For now, at least, I feel the considerable time put into learning PixInsight is starting to pay off and I’ve finally turned a corner with my processing.

 IMAGING DETAILS
ObjectLBN325 & 326 +  Barnard 345 &  SNR G082.2+5.3 DWB 156, 167, 165, 168, 170, 176,
ConstellationCygnus
Distance5,000 light-years?
Size>2o
Apparent MagnitudeNA
  
Scope William Optics GT81 + Focal Reducer FL 382mm  f4.72
MountSW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
GuidingWilliam Optics 50mm guide scope
 + Starlight Xpress Lodestar X2 camera & PHD2 guiding
CameraZWO1600MM-Cool mono  CMOS sensor
 FOV 2.65o x 2.0o Resolution 2.05”/pix  Max. image size 4,656 x 3,520 pix   
EFWZWO x8 + ZWO LRGB & Ha OIII SII 7nm filters 
Capture & ProcessingAPT + PHD2 +  DSS + PixInsight +  Photoshop CS3 + Topaz Denoise AI
Image Location            Centre  RA 20h 18’ 42.55”     DEC +46 25’ 03.12”        
ExposuresNB 300 sec x 53 Ha & x 38 OIII       BB 60 sec x 49 R, x 35 G & x 50 B Time: NB 7hr 58 min   BB 2hr 14 min  TOTAL 9hr  49 min   
 @ 139 Gain   21  Offset @ -20oC    
CalibrationDarks 5 x 300 sec & 10 X 60’    20 x 1/4000 sec Bias   5 x Ha & OIII Flats  10 x LRGB Flats     @ ADU 25,000
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time9th 13th & 14th September 2020  @ +21.00h  
WeatherApprox. 15-20oC   RH <=60%                  🌙 20% waning

                             

              

Reflections 2019

The website Watch This Space (Man) began in 2015 as I started out in astronomy and is a record of my personal journey, comments and thoughts.  Apart from the main blog, the website also contains links to other astrophotographers, astronomy tools, astronomy weather, and scientific papers etc., which can be accessed from the top menu.

Whilst there is a photo gallery of my work in this website, an overview of the better images can be found in the My Astrophotography FLICKR album, which can be found in the GALLERY menu.  Furthermore, this year I took the plunge and joined the Astrobin community, where my images can be found using the appropriate link also in the GALLERY menu.

Heat Map 2019

During the past year the site was visited from 64 different countries, literally from every corner of the world.  I always like to hear from anybody out there – comments, questions, help or just to say hello  – and can be contacted via details given in the ABOUT menu section or just leave a comment on any item if you prefer.

Reflections 2019 BannerX

Reflections is compiled at the end of each year as a review of my astronomy and astrophotography during the previous twelve months, together with some thoughts on possible future developments.

Overview, Images & Goals for 2020

The past year’s plan was simple: build-on and experiment with developments from the previous year, in particular using Plate Solving to achieve longer integration times and explore further the north sky, which I could now see from the new Shed Observatory and operates during the spring and summer months.

By routinely using Plate Solving integration times, now obtained over a number of nights or even months, have increased by up to four-fold compared to previous years.  As a result I concentrated on less objects but for longer time, achieving between 6 to 8 hours of subs on some occasions, the limiting factor as ever being British weather.  Although quite modest compared to those able to use fixed observatories, or in clear, dry climates with Bortle 1 or 2 skies, I was very pleased with the positive impact this had on my images.

Starting astronomy and astrophotography somewhat late in the day a few years ago, like many others after retirement, the learning curve was steep and often frustrating.  There were times I’ve almost considered giving up but with perseverance I’ve made progress and often get great pleasure from some of the results, as well as just enjoying and learning about this wonderful subject.  For me it is just a hobby but recognising some of my achievements and abilities acquired since starting out in 2014, I was especially proud this year to be elected a Fellow of the Royal Astronomical Society.  For all the help in reaching this point, I’d like to thank all those who have helped me from the astronomy community, wherever they are.

RAS logo

Favourite Images

My weakness in astrophotography remains processing but having at last obtained some good integration times, this year I made a greater effort to improve these techniques – with some success.  Adopting the theme less is more, I imaged just 17 different objects this year – of which nine were full narrow or broadfband images, with the rest being  experimental or DSLR – with a total integration time of 65 hours (2018: 25 objects & 43 hours).  The resulting images turned out well, achieving Picture of the Week on the British Astronomical Association website on six occasions.  It’s therefore difficult to choose favourites from this select group based on merit alone, so this year’s favourites (see below) represent those good images that also mark a significant milestone in my astrophotography.  Detailed reviews of these and all other images from 2019 are discussed in dedicated articles that can be found via the Blog Index under the ABOUT dropdown menu.

SHO2 CompF (Large)

Horsehead & Flame Nebula: Usually imaged in LRGB broadband, this narrowband SHO version produced a very different affect and colours, whilst also showing the beauty of the accompanying clouds of interstellar gas and dust.  Taken over three nights, at nearly 7-hours, this image was also one of my longest integration times to date.     

M101 HaLRGB final Closeup

M101 Pinwheel Galaxy: Given Bortle 5-6 skies, being on the Gatwick Airport flightpath and a using a small refractor, I struggle to image galaxies and often LRGB images in general from Fairvale Observatory.  However, on this occasion the combination of 5-hours HaLRGB subs and new processing techniques to enhance the colours, M101 proved the exception and is perhaps my first decent classic spiral galaxy imaged from home.  Moreover, the HII regions light up along the spiral arms with the addition of Ha wavelength, producing a dazzling and dynamic image. 

Picture saved with settings embedded.

Heart & Soul Nebula:  Combining existing data from 2018 of the Heart Nebula and new 2019 data of the Soul Nebula + the intervening space, this is my first albeit modest mosaic, which promises to open up significant possibilities in the future. 

RECORD CARD – 2019
Goal Specifics / Results Outcome
Improve broadband and narrowband imaging

 

Achieved major increase of image integration times and overall quality. MUCH, MUCH BETTER

 

Improve processing Continuing to make slow improvements, with greater use of new Photoshop techniques. BETTER

 

Expand & Improve Widefield Imaging Despite some good images of the Milky Way in the USA, I never used the Vixen Polarie tracking mount and did not make it to any other dark sky sites  = disappointing. FAILED

 

My objectives in 2019 mostly went well in (see above), so here goes for 2020:

  • Imaging: There’s always scope to improve imaging techniques but probably most of all I still need to improve guiding quality and increase exposure and image integration times even further.
  • Mosaic: Expand the use of mosaic imaging using Plate Solving and new CdC planning software.
  • Improve processing: I expect this will continue to be something of a challenge for some time to come unless I go to the dark side and adopt software such as PixInsight & / or APP.
  • New Observatory: Unfortunately this will not be a fixed obsy whilst I continue to live here at Fairvale which is unsuitable.  However, I’m hopeful that another location between the Main (North) Observatory and the Shed Observatory might open up the north sky better and by getting away from the high hedges that surround the garden allow longer imaging sessions than can be currently obtained at the Shed.
  • Other: My mind is always thinking about larger telescopes or a dual rig and / or a new high-end encoded mount but probably not until I make further progress with the above goals and / or move to a better dark sky location – dreaming is part of astrophotography = watch this space!

Although you never know, I don’t see any major breakthroughs in the coming year but more of the same – revisiting familiar objects in order to obtain new image versions based on greater integration time and hopefully using mosaic techniques to build-out images in order to encompass wider areas of the sky.  This year I was surprised to discover objects that I had hitherto considered out of reach from my location (M101, M51 etc.), as well as exciting features that were completely new to me and still hold great promise e.g. DWB 111 AKA the Propeller Nebula.

Looking back I’m very happy to say 2019 was an excellent year for astronomy and astrophotography, almost certainly my best yet.  You can’t ask for more than that and I hope that WTSM’s Reflections 2020 will record further such success.

Watch this space!

wtsm logo

 

2019 CHRONICLE 

Below is a quarter by quarter summary of my astronomy and astrophotography for the year, followed by an imaging record.

JANUARY TO MARCH

Towards the end of 2018 I decided to undertake a project, with the prime objective to gather a much longer period of integration than hitherto achieved by using my newly developed skill of Plate Solving.  I’d previously imaged the Horsehead and Flame Nebula in the more traditional colour palette, either with a modded DSLR or by LRGB broadband.  However, I’d recently seen this iconic image undertaken using the Hubble Palette to great affect and was inspired to do the same myself. Thereafter, for more than 2-months the clouds rolled in and I thought my project would then be impossible, not least because by now Orion had crossed the Meridian in the early evening and imaging times were at best limited.  But as is often the case with astrophotography everything suddenly changed and it was game on!

The first evening of clear skies since 11th November 2018 coincided with the full lunar eclipse on 21st January, which I was therefore able to image once again.  Then six days later a very untypical clear and quite warm period of weather arrived and I was able to complete my intended project after all, with further time to image both the Great Orion Nebula and the reflection nebula M78 + Barnard’s Loop (see images below).

HaLRGB2FINALcrop (Large)

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

Achieving much longer integration times of between 5 and nearly 8-hours, the impact on the resulting images was transformative.  I was especially pleased with the outcome of the Horsehead project in SHO (see Favourites Images section) but found the Ha-only starless version of the same scene (see below) particularly mesmerising, as the large HII structures throughout this region bring the image to life.

NGC 2024 Ha Starless2

By the end of February the night sky at 51o latitude has moved inexorably on to the so-called Galaxy Season, which provides something of a dearth of imaging opportunities for my 81mm telescope.  However, with a good patch of weather at the end of March, whilst experimenting with the Leo Group I noticed that small areas of Ursa Major region could be seen directly above for a couple of hours, which to my surprise opened up a whole new world of possibilities hitherto considered unavailable.  Shortly after I managed to obtain almost 5-hours of data on M101 the Pinwheel Galaxy, which is one of my best galaxy images taken from Fairvale Observatory (see Favourite Images section).

APRIL TO JUNE

Having discovered the albeit limited possibilities of seeing Ursa Major, I moved to the Shed Observatory early in April, which by then afforded slightly better views of the same area of sky and thereby to my great joy provided the possibility of imaging the wonderful Whirlpool Galaxy, M51.  Unfortunately time was somewhat limited but it was better than nothing and I was thrilled to obtain an image of this wonderful object for the first time.  Weather permitting I’ll be back for more data in 2020 with which to build on the promising result obtained this year.

LRGB Image FINALX2 (Large)

By the end of April just 8-weeks away from the summer solstice astronomical darkness is in short supply.  Fortunately having moved earlier to the Shed Observatory this year, I was in a good position to return to inaging the Bodes and Cigar Galaxies (see below), which had been my first ever image of north sky objects in 2018.

LRGBFinal (Large)

JULY TO SEPTEMBER

From May until late July the absence of Astronomical darkness makes astronomy difficult and frankly having progressed from the time of being a beginner, it is quite refreshing to take a break.  Therefore it was only after an evening viewing the partial eclipse on 16th July and a brief experiment with the Wizzard Nebula (something for the future) at the beginning of August, that much later I returned to astrophotography seriously.

SHO2SCcrop (Large)

Having messed up imaging the Soul Nebula with poor framing in 2018 and being at the Shed Observatory, I decided to re-image the Soul properly, together with some of the adjacent sky in order to combine the new data with last year’s adjacent Heart Nebula to form a mosaic of both objects.  I don’t know why but this was my first attempt at a mosaic.  Only very recently has integrated software for mosaic planning combining  Cartes de Ciel and Astrophotography Tool for image capture has been released.  However, on this occasion I planned and implemented the said mosaic imaging manually, with a satisfying outcome (see Favourite Images section) but with the new software now available I hope to embark on more extensive mosaic projects in the near future.

This year’s astrophotography has followed two themes, the aforementioned ‘less is more’ with the aim of producing better images using much greater integration times.  The second has been largely determined by chance, being the discovery of new objects that had hitherto either been unknown to me or considered to be out of view from Fairvale Observatory; the combination of my house, very high hedges + trees and adjacent houses obscures large swathes of the night sky.  Earlier in the year such chance had led me to the M101 and M51 galaxies and in the autumn it was first the iconic Pacman Nebula and then an exciting area of Cygnus constellation.

Pacman is not particularly large for my equipment but nevertheless produced a decent narrowband image, my last from the Shed Observatory for this year.  Not until late September did the clouds again relent for my next project that initially seemed something of a long shot but actually turned out very well.  The Propeller Nebula is located in a vast HII region of the Cygnus Constellation, which from my point-of-view was a complete surprise.  At some 25 arc seconds the nebula is again on the small side for my equipment but the complexity of the adjacent HII region transforms the wider image into something really spectacular (SHO version below), which I certainly intend to visit again next year to build on the current data and explore further afield the HII region which presents exciting possibilities.

SHO F HLVG (Large)

A subsequent long trip to the USA stopped all astronomy in Surrey but a couple of evenings out in Wyoming and Utah produced some incredible dark skies and DSLR Milky Way images (see below).  Despite the remoteness of Spilt Mountain in the UTAH section of the Dinosaur National Monument – designated a Dark Sky Area – whilst imaging at 20 second exposures only one-in-ten images were without a plane track, very sad.

IMG_2345 ComboX

OCTOBER TO DECEMBER

Prior to the arrival of Orion and other fun objects of the mid-winter night skies, imaging opportunities are sparse with my equipment but it’s been a couple of years since I last imaged M31 the Andromeda Galaxy and therefore for two evenings in late October it was time to give our neighbour the extended integration treatment.  At 7½ hours data acquisition went well but although the processed image is probably my best yet of this object, there’s room for improvement, which I suspect will require a move to more advanced processing software?

HaLRGBx5b (Large)

ASTROMINAGING RECORD 2019

No Date Type Object Name
       
1 21/01/19 DSLR Full Lunar Eclipse  
       
2 27/01/19* NB  Barnard-33 &

 NGC 2024

Horsehead & Flame Nebula
       
3 23/02/19* Combo M42 Great Orion Nebula
       
4 25/02/19* Combo M78 Reflection Nebula Orion
       
5 12/03/19 BB NGC443/444 Jellyfish Nebula
       
6 24/03/19 Combo M95/96/105 Leo-1 Group
       
7 29/03/19* Combo M101 Pinwheel Galaxy
       
8 10/04/19 Combo M51 Whirlpool Galaxy
       
9 13/04/19 BB M81 & m82 Bodes & Cigar Galaxies
       
10 16/07/19 DSLR Partial Lunar Eclipse  
       
11 02/08/19 NB NGC 7380 Wizzard Nebula
       
12 23/08/19* BB IC 1848 Soul Nebula +

Mosaic Link

       
13 26/08/19 NB NGC 281 PacMan Nebula
       
14 05/09/19* NB DWB 111 Propeller Nebula
       
15 Sept DSLR Milky Way Split Mountain Utah
       
16 22/10/19* Combo M31 Andromeda Galaxy
       
17 18/11/19 BB M74 Galaxy
       
18 18/11/18 NB SH2-240 Spaghetti Nebula
       

*multiple evenings        Combo = HaLRGB       Underlined = BAA published

POSTSCRIPT

The ones that got away – imaged but not seen in WTSM this year – warts and all

RHB_2ajelly (Medium)

I saw some wonderful narrowband versions of the supernova remnant IC 443 Jellyfish Nebula this year, in particular adopting a wider view to incoporate its sentinel-like parner stars Tejat (Mu Geminorum) left and the tripple star Propus (Eta Geminorum) right, together with the reflection nebula IC 444 in the background.  As an experiment I think it may hold promise but will require a lot more integration time to improve the quality, colour and bring out more of IC 444.

M95_96_105 (Medium)

I’ve tried the Leo-1 group (M95/96/105) before but, as they say, if you don’t succeed try again.  Unfortunately the passage of time didn’t help – I need a larger telescope to do these critters justice! 

IMG_2336 (Large)

Dinosaur National Monument – Split Mountain, Utah.  Even at this wonderfully remote location, which is one of the darkest places in the USA, passing planes still get in the way of a good image – just like at Fairvale Observatory

M74 LRGBx (Medium)

At <=10 arc minutes the spiral galaxy M74 is too much for my equipment.

SH2-240 AB combined Ha Stretch (Large)

Located between the constellations Auriga and Gemini, SH2-240, Simeis 147 AKA the Spaghetti Nebula is a very large (+3 degrees) supernova remnant but it’s very low brightness makes imaging extremely difficult.  In fact prior to and during capture in Ha-wavelength, I had no idea if it was even within the image frame.  Aggressive stretching shows that it was there but only much darker skies and probably longer exposure time is likely to produce a more viable picture. 

 

Horseplay

SHO2 CompF (Large)

Who doesn’t like Orion and its constituent parts – M42/43, M78, the Witch’s Head, Barnard’s Loop etc.?  For many its annual appearance in the night sky is greatly anticipated and will form one of the main astrophotography highlights of the year as it passes across the sky between late November and February.  For me a basic afocal image of the Great Orion Nebula for the first time in 2013 marked something of an epiphany, as it demonstrated the power of long exposures in capturing the otherwise hidden beauty and excitement of Deep Sky Objects.

Since taking up astronomy and then astrophotography, I always return to at least one of Orion’s  objects each year, initially to see if I could just capture it on camera with my equipment and then to try and improve the image of each target.  It’s been a gradual process but I’m pleased to say I’ve usually managed to achieve such improvements over time, which has been both satisfying and often exciting – such is the nature of these objects.  Progress almost always resulted from one or more of four developments: new equipment, new software, new techniques and better processing.

Each step was usually small but occasionally a quantum change took place, such has been the case during the past two years: first with the change from DSLR to a CMOS mono camera and then, more recently, learning to plate solve.  I was reluctant to change to a traditional CCD mono camera which usually requires very long exposures that, in my opinion, is incompatible with British weather, light pollution and the frequent overhead passage of aircraft where I live between Gatwick and Heathrow airports – if one doesn’t get me the other will, or the low flying helicopters that pass over my observatory throughout the night from nearby Redhill aerodrome!

It was therefore very fortunate that at the same time I wanted to upgrade my camera from a DSLR, the new CMOS sensor technology had literally just arrived on the market.  With low read noise and shorter exposures, the ZWO1600MM-Cool mono camera I purchased has been a revolution for me, as well as the entire astroimaging community.  Furthermore, the use of narrowband imaging has added a completely new dimension to my astrophotography – apart from the ability to image when the Moon’s about each month and defy light pollution, narrow Ha-OIII-SII wavelengths reveal a whole new world that is both interesting and often dramatic in appearance.

Notwithstanding these developments, I was hitherto hampered by limited integration times of just over two hours (at most) either east or west of the Meridian, until in 2018 I finally mastered (probably that’s overstating my current prowess) plate solving, thereby making integration times literally infinite.  All I needed now was clear skies! Despite my enthusiasm for astrophotography, there have been times over recent months when I’ve questioned my choice of hobby and even maybe giving up.  Given sufficient funds it is possible to have the most incredible imaging set-up, capable of obtaining equally incredible images – subject to user ability – but if the sky remains cloudy it’s no more than a pile of expensive junk!

Having obtained a very decent LRGB image of the Pleiades on 17th November, armed with the ZWO1600 camera and my new plate solving skills, I decided to take on a project over the winter months.  My objective was to obtain one very good image based on a much longer integration time than I’ve previously achieved, acquired by imaging the same object over as many nights as possible during December and January. However, as Robert Burns once put it “The best laid schemes o’ Mice an’ Men, / Gang aft agley,” (translated – the best laid plans of mice and men often go awry).  Apart from one evening that fortuitously coincided with the lunar eclipse on 21st January, the skies here remained obscured by cloud from November 18th until January 27th (or 70-days!!!) and I thought my project was scuppered, that is until the other qualities required of astronomy came into play: patience and good luck.

Picture saved with settings embedded.

My first image of the Horsehead & Flame Nebulae, 23rd November 2014: William Optics GT81 +FF, Canon 700D (unmodded), SW AZ-EQ6 GT mount, 30 x 90 secs @ ISO1600 + full calibration

The Horsehead and Flame nebulae are traditionally imaged in LRGB colour, indeed my first and subsequent images of these objects have been mostly undertaken in this way (see image above).   However, inspired by a narrowband image of these objects I’d seen earlier last year, I too wanted to try and capture these nocturnal bedfellows in narrowband and process the subs using the Hubble Palette technique.  Given the aforementioned cloud problem, by the time late January had been reached Orion was already slipping over the western horizon for another year and I thought the project was dead before it could even start, at which point good luck played its part.  Starting on 27th January and for three out of the four evenings, the sky cleared and I eagerly launched into the long awaited project.

Unfortunately by now Orion crossed the Meridian about 9 p.m. and most imaging could only be undertaken on the west side, thus limiting each night’s subs again to 2½ hours or less.  But with three nights in the bag before inevitably the cloud returned on the 31st January, I had secured 106 x 5-minute Ha, OIII and SII subs or 6 hours 50 minutes of total integration time, at least three times what I had ever previously achieved.  The key was plate solving, as each night I could return to exactly the same part of the sky and continue imaging the same objects to the nearest pixel.  Having obtained and reviewed the data, it was now time to start processing.

NGC 2024 Ha Starless2

Given the quality and quantity of data obtained I decided to take my time processing and, furthermore, try to use some new techniques to make the very best of the final image.  I was particularly keen to tame some of the brighter stars like the blue supergiant Alnitak located uncomfortably close to the Flame and at the same time bring out the interstellar dust that is present in the foreground below the Horsehead and across the lower right quadrant, which becomes evident in the starless processed Ha layer (see image above).  It took quite a while but in the end I am very pleased with the outcome, which I think shows all the benefits of longer data integration and the extra care taken processing.  The final SHO narrowband version of the Horsehead and Flame nebulae looks a real cracker, perhaps one of my best and has been worth all the patience and additional time taken to show these two objects and the adjacent region literally in a new light.

Needless to say, I’m already thinking about next year, cloud permitting!  I hope to return to the Horsehead and Flame for another playtime next winter, in order to acquire more subs with which to build further on the foundation achieved this year by a stroke of luck at the very end of Orion’s annual visit – can’t wait.

IMAGING DETAILS
Object (i)Horsehead Nebula (Barnard 33)  &  (ii)  Flame Nebula (NGC 2024)
Constellation Orion
Distance 1,500 light-years
Size (i)8” x 6”  &  (ii)  30’ x 30’
Apparent Magnitude +10.0
 
Scope  William Optics GT81 + Focal Reducer FL 382mm  f4.72
Mount SW AZ-EQ6 GT + EQ-ASCOM 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, HLVG
Image Location              & Orientation Centre  RA 05:40:57    DEC -02:30:55                     

Top = North 

Exposures 40×300 sec Ha+34×300 sec OIII+32x300sec SII  (Total time: 6hr 50min )   
  @ 139 Gain   21  Offset @ -20oC    
Calibration 5×300 sec Darks  20×1/4000 sec Bias 10xFlats Ha-OIII-SII  @ ADU 25,000  
Location & Darkness Fairvale Observatory – Redhill – Surrey – UK     Typically Bortle 5-6
Date & Time 27th, 28th & 30th  January 2019 @ +21.30h  
Weather Approx. <=1oC   RH <=90%                🌙 ½ to ¼ waning

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