Celestial hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  Bode's Galaxy  ·  Cigar Galaxy  ·  M 81  ·  M 82  ·  NGC 3031  ·  NGC 3034  ·  NGC 3077
M 81, M 82, NGC 3077 and IFN, 



    
        

            Ginge Anvik
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M 81, M 82, NGC 3077 and IFN

M 81, M 82, NGC 3077 and IFN, 



    
        

            Ginge Anvik
Powered byPixInsight

M 81, M 82, NGC 3077 and IFN

Acquisition details

Frames:
Astrodon 5nm Ha: 997×100(27h 41′ 40″) (gain: 139.00) -15°C bin 1×1
Astrodon 5nm Ha: 179×180(8h 57′) (gain: 139.00) -15°C bin 1×1
Astrodon Gen 2 B: 121×60(2h 1′) (gain: 76.00) -15°C bin 1×1
Astrodon Gen 2 G: 122×60(2h 2′) (gain: 76.00) -15°C bin 1×1
Astrodon Gen 2 Lum: 2350×60(39h 10′) (gain: 76.00) -15°C bin 1×1
Astrodon Gen 2 R: 144×60(2h 24′) (gain: 76.00) -15°C bin 1×1
Integration:
82h 15′ 40″
Darks:
100
Flats:
100
Flat darks:
100
Bortle Dark-Sky Scale:
4.00

RA center: 09h58m21s.45

DEC center: +69°1252.3

Pixel scale: 1.571 arcsec/pixel

Orientation: 117.526 degrees

Field radius: 1.209 degrees

WCS transformation: thin plate spline

More info:Open 

Resolution: 4434x3325

File size: 6.6 MB

Locations: Bjarkebu Observatory, Ytre Enebakk, Norway

Data source: Backyard

Description

Way too long since my last post, too busy on my day job, but here we go. I needed an object high in the sky with possibility to do some meaningful Ha-work too in case the clear nights were also moonlit, so I went for a well known pair and stuck with it for the remaining time of the winter after squandering the nebula season last autumn. This is my first attempt at CMOS-photography and I was pretty amazed at how long calibration and integration took with the number of sub exposures I had gathered. There are a few things you don't notice before you start stacking and stretching too. For instance, the swap from QSI CCD camera with internal filter wheel to ZWO cam and wheel (same filters) has introduced a reflection somewhere in the light path which produces halos around the stars. Must find a remedy for that. Anyway, tried to spend time enough to get a smooth IFN, but still process it in a way that it won't completely swamp the image. Got a fair amount of time on Ha too and blended it selectively into M81, M82 and NGC 3077 as the same parcentage of Ha added across the galaxies would be too much on one and too little on another. Not really sure if 60s, gain at 76, offset 21 for LRGB and 100s, gain 139, offset 100 for Ha is the right setting for my scope and sky. From what I read, it should be, but it all feels a bit strange coming from the CCD-world. Tried to increase to 180s subs for H-alpha which looked better. I'll probably increase LRBG sub length as well next season. It just felt like I was getting too much noise for the amount of exposure time. That can also be due to the fact that I'm seing more glow from an industrial area to the west...

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M 81, M 82, NGC 3077 and IFN, 



    
        

            Ginge Anvik

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