Hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  M 101  ·  NGC 5447  ·  NGC 5449  ·  NGC 5450  ·  NGC 5451  ·  NGC 5453  ·  NGC 5455  ·  NGC 5457  ·  NGC 5461  ·  NGC 5462  ·  NGC 5471  ·  Pinwheel galaxy
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M101 HaLRGB, 



    
        

            Chris White
Powered byPixInsight

M101 HaLRGB

Getting plate-solving status, please wait...
M101 HaLRGB, 



    
        

            Chris White
Powered byPixInsight

M101 HaLRGB

Acquisition details

Dates:
April 25, 2017 ·  April 27, 2017
Frames:
Astrodon Blue Tru-Balance I-Series Gen 2: 12×180(36′) (gain: 40.00) -20°C
Astrodon Green Tru-Balance I-Series Gen 2: 13×180(39′) (gain: 40.00) -20°C
Astrodon Ha 1.25 5nm: 31×180(1h 33′) (gain: 139.00) -20°C
Astrodon Luminance Tru-Balance I-Series Gen 2: 148×90(3h 42′) (gain: 40.00) -20°C
Astrodon Red Tru-Balance I-Series Gen 2: 11×180(33′) (gain: 40.00) -20°C
Integration:
7h 3′
Darks:
50
Flats:
50
Bias:
250
Avg. Moon age:
14.77 days
Avg. Moon phase:
1.49%

RA center: 14h03m04s.36

DEC center: +54°2213.8

Pixel scale: 1.292 arcsec/pixel

Orientation: -36.010 degrees

Field radius: 0.381 degrees

More info:Open 

Resolution: 1699x1274

File size: 1.2 MB

Description

This was a more challenging target than I thought it would be. I hope to have another clear night soon so I can try to add some Ha data to bring out the emission nebula within the galaxy arms. I also think that it is faint enough that despite imaging at f2.8, I could easily double or triple the lum channel. The details here are tough to bring out with such a heavy crop, but I think more time would help that.

C&C Welcome.

Comments

Revisions

    M101 HaLRGB, 



    
        

            Chris White
    Original
    M101 HaLRGB, 



    
        

            Chris White
    B
    M101 HaLRGB, 



    
        

            Chris White
    C
    M101 HaLRGB, 



    
        

            Chris White
    D
    M101 HaLRGB, 



    
        

            Chris White
    F
  • Final
    M101 HaLRGB, 



    
        

            Chris White
    G

B

Description: I had a fluke clear sky that lasted for about two hours and was able to get some Ha. This is my first HaLRGB, and I struggled with the processing. I'm not quite there, but happy with the progress.

Uploaded: ...

C

Description: Ok, Final Rev for now. I changed the point in processing where I combined Ha to Red, and was able to get a bit more control over it. The spirals are back to blue, stars are back to orange, and the overall effect of Ha is a bit more subtle. How does this look?

Uploaded: ...

D

Description: While I feel that I have been making progress on this image, Rev C still did not satisfy me. The addition of Ha was nice, but I lost the warm glow of the galaxy core. For this revision, I combined Ha to the Red channel at 50/50 BEFORE combining for RGB. This plugged in the Ha where I wanted it, but did not overpower the rest of the galaxy, allowing blues to be natural and the core to retain the warmer glow. This has been a super challenging image for me, but finally, I am happy with the result.

Uploaded: ...

F

Description: For this revision I utilized arcsinh stretch for the RGB integration. This allowed me to retain a TON of color data that I washed out with my previous histogram stretch. This includes the orange glow in the galaxy core as well as the blue and red in the spiral arms particularly near the galaxy core. Stars across the image have better colors as well, particularly the fainter orange stars.

Uploaded: ...

G

Description: For this revision I utilized arcsinh stretch for the RGB integration. This allowed me to retain a TON of color data that I washed out with my previous histogram stretch. This includes the orange glow in the galaxy core as well as the blue and red in the spiral arms particularly near the galaxy core. Stars across the image have better colors as well, particularly the fainter orange stars. -

Uploaded: ...

Sky plot

Sky plot

Histogram

M101 HaLRGB, 



    
        

            Chris White

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