Monkey Business

Constellation names mostly originated from ancient Middle Eastern, Greek, and Roman cultures, when they identified groups of stars and named them after their gods, goddesses, animals, and objects that were important to them.  Other world-wide groups and throughout time – Native American, Asian, and African – have also made and named similar pictures from star groups based on their cultures and related beliefs.  Given the number of stars observed when looking up into a clear dark sky, it is obviously helpful to ‘construct’ familiar patterns and adopt memorable names, which can then be used to identify areas of the sky in a way that can be easily identified by all.  I have no problem with this long and well-established convention, which despite their antiquity works just as well in the modern world but I do have an issue with nicknames.

I’ve smiled at some of the nicknames given to popular, usually deep sky objects that have been well established by astronomers, but despite the possible use of describing their form, I am increasingly finding them a distraction when considering the merit of astrophotography images: Seagull Nebula, Running Man Nebula, Pelican Nebula etc.  The problem is that they absolutely do look like the object they’re meant to depict but, like an earworm is to music, once seen they are difficult to view any other way.

With this partly in mind, for the first time in seven years I recently chose to image NGC 2174 again.  I previously used the William Optics GT81 with a modded Canon 550D DSLR camera, which resulted in an image that wasn’t too bad, except it looked like a monkey!  Given its nickname of the Monkey Head Nebula, this was to be expected but unfortunately, thereafter the picture of a monkey has remained with me ever since when I view NGC 2174 images.  The challenge on this occasion was therefore to limit the monkey’s impact on the image, thereby showing the object for what it really is – an emission nebula.

Using the same OTA but with a mono CMOS camera and a good set of filters, the new data set obtained was much improved, and with better processing experience it was time to see the monkey (or not) in a new light.  The first thing to do was present the image in an orientation that produces a more favourable perspective (less monkey like).  Using a basic SHO palette in PixInsight the initial image was promising (see below) but with an alternative PixelMath dynamic SHO palette* and then processing with autocolor script, color saturation, Russell Croman’s XT-suites and other tweaks, I was pleased to see that the monkey was nowhere to be seen in the final image (see image at the top-of-the-page), or at least to my eye.

At last, it is now possible to look at NGC 2147 and see the inherent features of this interesting emission nebula, where new stars are being born at a rapid rate. Moreover, the inner details can now be clearly viewed within, thus also showing the associated open star cluster NGC 2175 and more.  As a result of this monkey make-over, the NGC 2174 image now not only looks much better but critically, I no can longer see the ape!  Now where’s that Seagull?

 IMAGING DETAILS
ObjectNGC 2174
ConstellationOrion
Distance6,400 light-years
Size 40 arc secs
Apparent Magnitude+6.80  
  
Scope William Optics GT81 + Focal Reducer FL 382 mm f4.72
MountSW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
GuidingWilliam Optics 50mm guide scope
 + Starlight Xpress Lodestar X2 camera & PHD2 guiding
CameraZWO ASI294MM CMOS sensor
 FOV 2.87o x 1.96o Resolution 2.50”/pix  Max. image size 4,144 x 2,822 pix   
EFWZWOx8 EFW & 31mm Chroma HSO & LRGB filters 
Capture & ProcessingAstro Photography Tool + PHD2 + Deep Sky Stacker, PixInsight v1.8.9-1, Photoshop CS3
Image Location              & OrientationCentre = RA 6:09:39.801      DEC +20:29:12.851                         Right = North        Up = East     
*Image PI Processing: Dynamic Pixel Math  R = (O^~O)*S+~(O^~O)*H
G = ((O*H)^~(O*H))*H+~((O*H)^~(O*H))*O
B = O
ExposuresHa 36 x 300 sec (3hr), OIII 30 x 300 sec (2hr 30m), SII 32 x 300 sec (2hr 40m) Total Integration Time: 8hr 10 min     
 @ 120 Gain   30 Offset @ -15oC    
Calibration5 x 300 sec Darks  15 x  HSO Flats & Dark Flats         @ ADU 32,000
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time25th + 26th February + 2nd March 2023 @ +19.00h  
WeatherApprox. < 3oC   RH >=65%                  🌙 +25 to +50%

Reach For The Stars

Preceding the arrival of what is for many astronomers the highlight of the year, the Orion constellation and all it’s objects, is the appearance of the majestic Pleiades open star cluster (Messier 45) in the constellation of Taurus.  The so-called Seven Sisters consists of hot blue luminous stars that formed during the past 100 million years, which are expected to last another 250 million years and can be easily observed with the naked eye even here at Fairvale Observatory (Bortle 5/6).  

I have imaged this exciting star cluster before but with astrophotography and especially iconic objects such as the Pleiades, one is always drawn back for another try.  Now armed with Chroma filters and a growing list of PixInsight skills acquired since last imaged late in 2018, I wanted to tease out more details of the fine wispy dust cloud through which the Sisters are passing and forms the signature of all good Pleiades’ images.  Furthermore, with longer exposures and total integration time greater than before, maybe I could also capture something of the abundant interstellar dust that is present across the wider background?  

I am therefore very pleased that the final image (top of the page + cropped version above) which has more than achieved these objectives and marks a significant improvement on my previous attempts – it’s always worth trying that little bit more.

 IMAGING DETAILS
ObjectM45 The Pleiades AKA Seven Sisters
ConstellationTaurus
Distance444 light-years
Size110’
Apparent Magnitude+1.6
  
Scope William Optics GT81 + Focal Reducer FL 382mm  f4.72
MountSW AZ-EQ6 GT + EQASCOM computer control
GuidingWilliam Optics 50mm guide scope
 + Starlight Xpress Lodestar X2 guide camera & PHD2 control
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 EFW & Chroma 31mm LRGB filters 
Capture & ProcessingAstro Photography Tool + Deep Sky Stacker PixInsight v 1.8.8-11,  Photoshop CS3, Topaz AI Denoise
Image Location & Orientation Centre: RA 03:47:03  DEC 24:03:08  Top = North   Right = West   
Exposures12 x 300 sec LRGB   Total time: 4 hours   
 @ 139 Gain   21  Offset @ -20oC    
Calibration5 x 300 sec Darks  15 x Flats & Dark Flats LRGB    @ ADU 25,000  
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5
Date & Time6th  December 2021 @ +19.15h  
Weather & MoonApprox. <=4oC      RH >=85%          🌙 New Moon          

Orion In A New Light

In ancient history Orion’s stars were considered to form a pattern that resembled a hunter holding a club above with his right arm and a shield in front with his left.  The appearance of Orion each year marks the highlight of the astronomy for many including me but for the second year running months of continuous cloud have precluded any astronomy since October; I note from comments online far-and-wide that this phenomenon has prevailed across much of the northern hemisphere, no doubt resulting in a lot of unhappy astronomers.

The Anantomy of Orion

Finally the clouds briefly relented over Fairvale Observatory in February but only for a few hours each time, thus eliminating the possibility of imaging with a CMOS mono camera.  Faced with these problems I therefore returned to my somewhat neglected modded Canon 550D camera and suitable lenses for appropriate widefield compositions, in order to image some classic targets around the Orion constellation in a broader context.  Having first whetted my appetite with the Samyang 135 f2 and its large 9.45o x 6.30o FOV to successfully image the iconic area that encompasses Orion’s belt, the Horsehead Nebula and M42 (see Going Big), it was time to go really big in order to capture the entire constellation literally and figuratively in a new light.

Seven bright stars define the area which outlines the torso and upper legs of Orion the Hunter: Betelgeuse, Bellatrix, Rigel and Saiph at the top and bottom, connected across the centre by his ‘belt’ formed from Alnitak, Alnilam and Mintaka.  The H-shape thus created by these stars is a familiar sight over the winter months but like so many asterisms of the night sky all is not what it seems.  Plotting the distance from Earth of each star it is immediately obvious that their spatial relationship significantly changes the shape of the constellation compared to what as we perceive by eye.  It is a sobering thought that with the passage of time those asterisms familiar to astronomers today will look very different in the future as the stars move though space and therefore continue to change their relative positions, look and shape.          

StarBetelgeuseBellatrixRigelSaiphAlnitakAlnilamMintaka
Distance from Earth* (light years)  643  243  772  724  800  1,359  900
*Source: Royal Greenwich Observatory

Click HERE for annotated version of the Orion Constellation in 3D ref. Space Science Telescope Instititue

The Canon ‘Nifty Fifty’ 50mm f1.8 fixed aperture lens is perfect for an ultra widefield image of Orion. Whilst the glass is excellent, focus leaves a lot to be desired and once achieved needs to be secured with tape

Aside from the said visual perspective of Orion, like so much of space we only see a fraction of what is really present in the Universe but can nevertheless often be disclosed by astrophotography.  And so I next decided to image the entirety of Orion, this time with a basic Canon 1.8 50mm lens – the so called “nifty fifty”- with the purpose of capturing in one shot the constellation with which we are all familiar, together with vast spectacular HII-regions that encompass much of the constellation but usually remain unseen. This camera-lens combination provides an enormous 25.5o x 17.0o field-of-view (x7 > Samyang lens, x83 William Optics GT81!) albeit with lower resolution, which perfectly encompasses most of Orion and therefore the entire arc of Barnard’s Loop on the left and the Angelfish Nebula (Orion’s “head”) located above and between Betelgeuse and Bellatrix. 

Above: Orion constellation from Fairvale Observatory 24th December 2014 (Left) compared with long exposure image + modded camera 10th February 2020 (right)

Barnard’s Loop is an emission nebula, forming part of the Orion Molecular Cloud Complex which also contains the dark Horsehead and bright Great Orion Nebulae M42.  The Loop is believed to have originated from a supernova explosion about 2 million years ago, which is now ionized by stars from within and around the Orion Nebula and takes the form of a large arc centred approximately on the Orion Nebula. Discovered and photographed by E. E. Barnard in 1894, this vast feature extends over some about 600 arcminutes when viewed from Earth or physically up to 300 light years across, depending on the distance from Earth.

The Angelfish Nebula SH2-264 is centred on the young star cluster of Lamda Orionis, of which Meissa is the brightest. An HII-region with an apparent size of 5 degrees and actual size of 150 light years, it is also an emission nebula that is energised by the aforesaid star cluster and is considered to form the so-called head of Orion.

Having previously imaged notable parts throughout Orion, I’ve long wanted to capture the full extent of this wonderful constellation in all its glory and am very pleased with the outcome on this occasion.

DSLR IMAGING DETAILS*
ObjectOrion Constellation
ConstellationOrion
Distance243 to 1,360 light-years
Size594o2
Apparent MagnitudeVaries
  
Lens / Scope Canon 50mm f1.8  
MountSW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
GuidingNo Guiding
CameraCanon 550D modified
 FOV 25.5o x 17.7o Resolution 17.72”/ pixel      
Capture & ProcessingAstro Photography Tool + PHD2 Deep Sky Stacker, PixInsight, Photoshop CS3 & Topaz Denoise AI
Image Location &        OrientationCentre  RA 05:37:37.3      DEC +00:48:50.26         
Top = North    Right = West     
Exposures & Aperture42 x 120 sec  @ ISO800 Total: 1hr 24 min F1.8   
Calibration5 x 120’ Darks,  20 x 1/4000 sec Bias  20 x Flats         
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time10th February 2021  @ +21.00h  
WeatherApprox. <=0oC   RH <=65%                  🌙 NEW MOON

*For higher resolution and plate-solving data go to Astrobin HERE and click on image

Going Big – Widefield Imaging

After considering the limitations created by UK weather, I chose to purchase a Samyang 135 f/2 lens last year, rather than typically moving to a larger aperture / focal length scope.  Unfortunately because of the aforesaid poor weather conditions that have since prevailed its use has so far been restricted.  However, after literally months at last the clouds briefly relented over Surrey recently and I was able to get a couple of hours imaging the Orion constellation.

I really enjoy the widefield aspect of astrophotography, particularly without resorting to a mosaic which is too often impractical given the lack of favourable imaging conditions in the UK.  Such images can produce another perspective of favourite targets previously imaged with a telescope or are just fascinating in their own right.  For the moment I’m using the Samyang lens at f2.8 with a modded Canon 550D, manual focus and no guiding but eventually intend to pair it with a mono CMOS camera.  This combination results in a whopping 9.45o x 6.30o field-of-view, no-less than 11x that of my standard William Optics GT81 and ZWO1600 set-up.  Whilst using the lens at its maximum f/2.0 aperture would be even better, stopping down to f2.8 improves focus quality and removes any possibility of vignetting.

In this instance I chose to frame the image around the area of Orion’s Belt and the Great Orion Nebula M42 but such is the lens’ extensive field-of-view that M78 and part of Barnard’s Loop have also sneaked into the lower left corner.  Even though this was something of a ‘quick & dirty’ session resulting in just 112 minutes integration time, looking closer at M42 (see cropped version) the detail and colours achieved with this lens has far exceeded my expectations.   As well as the detail of M42 and the Horsehead Nebula, I’m also impressed at how well the lens has dealt with the usually difficult large bright stars of Orion’s Belt & others in the image. 

The quality produced with this small lens is quite extraordinary and it is definitely one of my star astronomy purchases.  Going forwards the challenge will be to find suitable targets that can fill its very large field-of-view, as well the inevitable wait for clear skies!

DSLR IMAGING DETAILS*
ObjectOrion: M42, Horsehead, M78 & Barnard’s Loop
ConstellationOrion
Distance243 to 1,360 light-years
Size594o2
Apparent MagnitudeVaries
  
Lens / Scope Samyang 135 f/2  
MountSW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
GuidingNo Guiding
CameraCanon 550D modified
 FOV 9.45o x 6.30o Resolution 6.45”/pix      
Capture & ProcessingAstro Photography Tool + PHD2 Deep Sky Stacker, PixInsight, Photoshop CS3 & Topaz Denoise AI
Image Location  &             OrientationCentre  RA 05:36:48      DEC -03:11:30.4               
Right = North   Top = West     
Exposures & Aperture56 x 120 sec  @ ISO800 Total: 1hr 52 min F2.8   
Calibration5 x 120’ Darks,  20 x 1/4000 sec Bias  20 x Flats         
Location & DarknessFairvale Observatory – Redhill – Surrey – UK        Typically Bortle 5-6
Date & Time3rd February 2021  @ +22.00h  
WeatherApprox. 6oC   RH +85%                  🌙 67% waning
*For high resoluton image go to Astrobin HERE and click on image