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Leo Triplet (M65, M66, and NGC 3628), The Leo Triplet is a small group of galaxies about 35 million light-years away in the constellation Leo.
large version at astrobin
Date: 4th January and 2nd February 2019
Mount: Skywatcher EQ6-R Pro
Telescope: Orion 10" f/3.9 Newtonian Astrograph
Camera: Nikon D5300 self modded full spectrum
Total exposure: ~3 hours
Subs : 300sx36, Flats, Bias, Darks
Guide Scope: Orion 50mm
Guide Cam: ASI120MM
Filter: Optolong UV/IR cut
Corrector: Baader MPCC Mark III Coma Corrector
Stacking: Deep Sky Stacker
Location: Ridiyagama, Sri Lanka
thank you and clear skies.
I wasn't going to share this, but what the heck. The winter of discontent continues, so i guess even this little data has to constitute an image these days.
After what seemed like an age of night after night of clouds, we had a rare few hrs of clear skies one night last week. So i managed to grab a whopping 9 x 7 mins of the Horsehead Nebula before it disappeared behind the neighbor's house. I then needed something else to aim for, so i brought up the Leo Triplet Sequence in SGP and managed to nab about 2.75 hrs in total, before the clouds returned. It really, really needs double, if not triple this amount, so i wasn't really intending on processing this tbh. I was really just messing about in APP and PS testing several things out, so there was no proper workflow being adhered to. I took an Auto DDP stretch out of APP and quickly processed it in PS, without much care. I noticed it was lacking in colour, so i thought this would actually be a good candidate to try out some ArcSinh Colour-Preserving stretches, so i took another linear stack and used Mark Shelley's excellent PS method for doing the colour-preserving stretches. Lo and behold, i ended up with a stack that was very rich in colour, so much so in fact that the sky background had also mottled up pretty bad. So i used a mask to only apply the rich colours to the stars and galaxies of the original image, and it made a HUGE difference. It was only at this stage that i suddenly thought i might as well actually go ahead and make an image out of it.
I really want to stretch it more, but it just can't take it. There's just not enough data, end of story. In fact i may have already stretched it too far as it is. The background is a tad lower than i would have liked as well, but it was needed to help suppress the noise. I've ran quite a bit of NR too, more than i'm usually comfortable with, and it's still noisy. I know what the answer to that is of course, more data! ? (not likely). I do quite like the colours though ?
24 x 420s (2.75 hrs)
80ED (x0.85), D5300, HEQ5-Pro, IDAS-D1.
Resized to 66% to help hide some of the warts!
By Davide Simonetti
The Leo Triplet - a target that I needed to image again as previous efforts haven't really done it justice. This is the most successful attempt so far, largely thanks to the ZWO ASI1600MC Pro camera and by giving it plenty of exposure with not too much gain making for a smoother background and bringing out dust lanes and other details in the galaxies.
014 x 090 second exposures at 161 Gain cooled to -20°C
081 x 090 second exposures at Unity Gain (139) cooled to -20°C
010 x 120 second exposures at Unity Gain (139) cooled to -20°C
016 x 180 second exposures at Unity Gain (139) cooled to -20°C
Total integration time = three hours, 30 minutes and 30 seconds
149 x dark frames
116 x flat frames
200 x bias/offset frames
Captured with APT
Guided with PHD2
Processed in Nebulosity, Fitsworks, and Photoshop
Telescope: Sky-Watcher Explorer-150PDS
Mount: Skywatcher EQ5
Guide Scope: Orion 50mm Mini
Guiding Camera: ZWO ASI120MC
Imaging Cameera: ZWO ASI1600MC Pro
Baader Mark-III MPCC Coma Corrector
Light pollution filter
After much wailing and gnashing of teeth, we have finally been able to get our dual rig up and running. The rig consists of two William Optics Star 71s - one is a Mark I (5 element) and the other is a Mark II (4 element). They have identical focal length and FOV. Cameras are a Moravian G2-8300 and an Atik 383L. Filters are Baaders. The rig sits on top of a new SkyWatcher EQ6-R. The object chosen was somewhat random - the Leo Triplet - just to check everything was aligned, orthogonal and so on. This was, in hindsight, not the best choice since the Triplet soon started dipping into the light polluted part of my sky. I got only a hint of the tidal tail - possibly because of the LP, possibly because I stuck (mostly) to 5 minute exposures as I was testing the rig. On the second night I did get some 15 minute luminance exposures, but I did not get sufficient (I think) to bring out the tail.
I am grateful to @swag72 on two counts. Firstly, she talked me into keeping the faith with the Star 71s (I was going to get an Esprit 80 and work around the different FOVs). Secondly, she suggested I try the (relatively inexpensive) EQ6-R (I had been thinking about an Avalon).
Luminance: 44x300" bin 1x1 Luminance: 10x900" bin 1x1 Red: 15x300" bin 1x1 Green: 15x300" bin 1x1 Blue: 15x300" bin 1x1 This amounts to 9 hours 55 minutes captured over 2 (and a bit) indifferent nights - at present I am only getting around 4 hours of 'Astro dark' per night. [EDIT: Please note there are (hopefully) improved versions a couple of posts below.]