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Contains:  NGC 3077, M 82, NGC 3034, M 81, Bode's nebulae, NGC 3031, NGC 2976
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M81 galaxy group, 





    
        

            Victor Van Puyenb...
M81 galaxy group

M81 galaxy group

Technical card

Resolution: 4172x2694

Dates:Jan. 20, 2017

Frames: 85x60" ISO800

Integration: 1.4 hours

Flats: ~20

Bias: ~20

Avg. Moon age: 22.65 days

Avg. Moon phase: 44.64%

Bortle Dark-Sky Scale: 7.00

Mean SQM: 19.43

Temperature: -4.00

Astrometry.net job: 1423257

RA center: 9h 55' 57"

DEC center: +69° 3' 7"

Pixel scale: 2.761 arcsec/pixel

Orientation: 91.430 degrees

Field radius: 1.905

Data source: Backyard

Description

The different revisions of this image are meant to show how my image acquisition and processing improved over time.

The M81 galaxy group in the constellation Ursa Major contains 34 galaxies and is located close to our own Local galaxy group. Two prominent members are Bode's Nebula (M81) and the Cigar galaxy (M82), popular targets for amateur astronomers due to their relatively large size and brightness (source: Wikipedia). How many galaxies can you count? (I can spot 10 galaxies in the full resolution picture)

Original description May 4, 2016:

My shots are normally limited to the southern inner city sky. This was taken during my first night out in a suburban area, where I aimed my telescope at the northern sky for the first time. Even used my polar scope for the first time. I'm pretty happy that these objects are visible with my simple setup, and under heavy light pollution. However, the images lack color after color correction, which is unfortunate. I should probably change my workflow to bring out the galaxy color.

Acquisition details:
Scope: Orion ST-80
Camera: Canon 450D
Mount: Skywatcher EQ5 Pro
Frames: 20x30" ISO1600, 11x60" ISO1600
Flats: 20
Bias: 72

Revision B: I still had 20 extra 30 second subs from the same night laying around and learned how I could add these to my DSS stack (also added bias frames). Then I used a new workflow in Startools to bring out more color and correct the lens aberrations.
Revision C: Cropped the frame from rev. B to match the rule of thirds
Revision D: Post-processed for the first time in PixInsight.

NEW DATA acquisition on January 21, 2017
Revision E: We had a couple of nights without clouds, so I revisited this target with my new scope and quadrupled the integration time. Still learning how to use all the tools PixInsight has to offer. Probably pushed the data too far, the background is really noisy.

Comments

Author

VicV
Victor Van Puyenb...
License: None (All rights reserved)
5191
Like

Revisions

  • M81 galaxy group, 





    
        

            Victor Van Puyenb...
    Original
  • M81 galaxy group, 





    
        

            Victor Van Puyenb...
    B
  • M81 galaxy group, 





    
        

            Victor Van Puyenb...
    C
  • M81 galaxy group, 





    
        

            Victor Van Puyenb...
    D
  • M81 galaxy group, 





    
        

            Victor Van Puyenb...
    E
  • M81 galaxy group, 





    
        

            Victor Van Puyenb...
    F
  • Final
    M81 galaxy group, 





    
        

            Victor Van Puyenb...
    G

D

Original dataset reprocessed with PixInsight

E

Complete revision with new telescope and more integration time

F

Entire frame reprocessed with less aggressive stretch.

G

Added HDRmultiscaleTransform and increased the saturation

Sky plot

Sky plot

Histogram

M81 galaxy group, 





    
        

            Victor Van Puyenb...

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