DeepSkyHosting

a group of galaxies in the constellations Ursa Major and Camelopardalis, including galaxies Messier 81 (Bode's Galaxy) and Messier 82 (Cigar Galaxy) and interstellar dust

Category:Deep Sky
Published:
1319
a group of galaxies in the constellations Ursa Major and Camelopardalis, including galaxies Messier 81 (Bode's Galaxy) and Messier 82 (Cigar Galaxy) and interstellar dustNGC 2630NGC 2631NGC 3063NGC 3174NGC 3194NGC 3218NGC 3231IC 2438IC 2440NGC 2614NGC 2629NGC 2633NGC 2634NGC 2636NGC 2641NGC 2646NGC 2650NGC 2715NGC 2748NGC 2760NGC 2787NGC 2810NGC 2938NGC 2957NGC 2959NGC 2961NGC 2963NGC 2976NGC 2977NGC 2985NGC 3027NGC 3031NGC 3034NGC 3061NGC 3065NGC 3066NGC 3077NGC 3144NGC 3147NGC 3155NGC 3183NGC 3252NGC 3343NGC 3348NGC 3364IC 511IC 520IC 529IC 2389IC 2574IC 2600IC 2601
Resolution:
8000x5333 px
File size:
35833 KB

Photo description / processing

Probably my most agonizing astrophotography to date. I collected signal for last year's hour-long session on the "leftover" time from shooting other objects this winter during the remaining dark time, trying to align the field on the stars based on last year's data. It resulted in 3 separate sessions of 1.5-2 hours per night. Due to the limitations of my equipment and tracker, I set exposures at 30 seconds, so I ended up with a lot of frames - almost 1000 together with last year's session. I couldn't manage to stack such a quantity in PixInsight; it required 2.5 TB of free disk space and used all the RAM, and in the end, it still gave some error and wouldn't build the final stack. After the 4th attempt (each taking over a day to process), I had almost given up and wanted to abandon the whole thing, but decided to try a different approach. I stacked the individual sessions from each night separately and then stacked those stacks into one, and "oh, miracle!" it finally worked! But by then, I had no mental energy left to process the result :)) I only returned to it just now, after 2 months. Let it be like this for now, maybe I'll redo it later, or better yet, reshoot it :))

Technical information

Telescope/Lens
Samyang 135mm f/2 ED UMC
Camera
Nikon D850
Mount
iOptron SkyTracker
Software
Pixinsight, Adobe Photoshop
Location
Батецкий р-н Новгородская область, Россия

Light pollution

Blue, Bortle 3 zone

Date taken
vk.com/cerba?w=wall7619458_14356

Exposure

  • 977 × 30″ · ISO/Gain: 1600 ·

Total exposure: 8 h 9 m

Comments

lxkor
Very cool! I like how the galaxies are rendered, not to mention the dust.
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Stanislav Borodinov
Excellent work! I also have a D850 and wanted to ask—how do you shoot your dark frames? Here, it's 8 hours of exposure, and the temperature clearly changed significantly... are bias frames needed for it?
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Anastasiya TretyakovaReply to Stanislav Borodinov
Here are 4 nights of data, each with 1.5-2 hours of exposure, separate calibration frames, and a separate stack. My struggles are described in the caption under the photo.
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Anastasiya TretyakovaReply to Stanislav Borodinov
I shoot darks at the end of the light frames session. Yes, the temperature can change during the shoot, but I don't want to shoot a dark after every light frame (as is recommended) at the expense of total integration time.
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