Molecular Clouds in Cepheus: MBM 163, 164 & 165 and LBN 569.  

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(@maurice_toet)
Brown Dwarf Customer
Joined: 2 years ago
Posts: 6
August 27, 2018 14:43  

Rarely imaged Molecular Clouds in Cepheus: MBM 163, 164 & 165 and LBN 569. MBM is an abbreviation for Magnani, Blitz and Mundy who identified/catalogued 57 molecular clouds at high galactic altitudes in 1985.

https://www.mauricetoet.nl/DeepSky/i-5Z9v6J4/A

Imaged with a Nikon D810a and Takahashi Epsilon-180ED on A-P Mach1 GTO3. Total integration time of 26.5 hours using 5 min. subs @ ISO 400 (318 light frames). Dither-guided with a Lacerta MGEN standalone autoguider (Vixen 70S guidescope). Captured during 6 nights (August 6, 8, 10, 11, 13 and 17) in Izon-la-Bruisse, Drôme, France.

At the beginning of each session, 30 flat frames were captured. Offset correction with a master bias frame of 200 bias frames. I didn't use dark frames.

Processing with APP. Settings other than default:

- noise weighted integration;

- MBB enabled: 5%;

- LNC enabled: 1st degree, 1 iteration.

DDP stretch: 20% BG - 3 sigma - 2.5% base.

Light pollution removal / fixing gradients: marking background areas with several dozen squares.

Post-processing in Adobe Photoshop CC: increasing colour vibrance/saturation (in RGB mode and on a and b channels in Lab colour mode), tightening star edges, enhancing nebulas/midtones (curves with layer mask to protect the stars), very slight noise reduction in the background (using noise reduction in  Camera RAW).

Full field of view in colour:

Contrast enhanced monochrome version (with less stars):

Annotated version:

I 'discovered' this area by browsing / exploring the Aladin Sky Atlas. Last February I tried out a part of this area using the digitized POSS-II data (red and blue plates). Now I can show my result and that of the 48-inch f/2.5 Oschin Schmidt Telescope side-by-side.

 

This topic was modified 5 months ago 2 times by Maurice Toet

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(@minusman)
Red Giant Customer
Joined: 2 years ago
Posts: 97
August 27, 2018 20:15  

😍Wow


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(@mabula-admin)
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Joined: 2 years ago
Posts: 1844
September 3, 2018 23:26  

Hi Maurice @maurice_toet,

Wow indeed, what a superb image, have rarely seen this 😉 !

Fantastic work to stick to such a long integration time for one object while on holiday ( I assume ? ) in La France.

Did you see clear differences with the integration weights? Any particular reason why yo used noise weighting ?

Thanks a lot for sharing 🙂 

Mabula

Main developer of Astro Pixel Processor and owner of Aries Productions


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(@maurice_toet)
Brown Dwarf Customer
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September 4, 2018 17:01  

Thanks Mabula,

This was indeed captured during my holiday in France. My goal was to capture at least 25 hours of integration time...

I have to confess I haven't made several integrations with different weight settings to compare. What I could have done (to save calculation time) is to integrate say 30 frames (instead of 318) with different weight settings for comparison. I decided to use noise weighting as I wanted to have the least of noise as possible in the 'background'. 


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(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 1844
September 25, 2018 21:01  

Hi Maurice @maurice_toet,

"I have to confess I haven't made several integrations with different weight settings to compare. What I could have done (to save calculation time) is to integrate say 30 frames (instead of 318) with different weight settings for comparison. I decided to use noise weighting as I wanted to have the least of noise as possible in the 'background'. "

Yes good argument, I think it should have proven to be a good choice.

Another way to test integration settings, is by integrating only a crop of the reference frame. That should run much quicker as well 😉

Thanks again for sharing this beautiful result...

Mabula

Main developer of Astro Pixel Processor and owner of Aries Productions


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