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 - Pinwheel Galaxy, 



    
        

            Steve Ludwig
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M101 - Pinwheel Galaxy

Getting plate-solving status, please wait...
M101 - Pinwheel Galaxy, 



    
        

            Steve Ludwig
Powered byPixInsight

M101 - Pinwheel Galaxy

Acquisition details

Dates:
March 9, 2022
Frames:
72×300(6h) ISO200
Integration:
6h
Avg. Moon age:
6.54 days
Avg. Moon phase:
41.08%
Bortle Dark-Sky Scale:
4.00

RA center: 14h03m03s.27

DEC center: +54°2053.2

Pixel scale: 1.197 arcsec/pixel

Orientation: -145.483 degrees

Field radius: 0.491 degrees

WCS transformation: thin plate spline

More info:Open 

Resolution: 2396x1732

File size: 1.2 MB

Data source: Backyard

Description

Equipment

- Main scope: Bresser Messier 10" Newton (254/1270)
- Main camera: Nikon D3300 (unmodified)
- Guide scope: Orion AC 50/162 Deluxe Mini
- Guide camera: ZWO ASI 290MC
- Mount: Skywatcher EQ6-R
- Explore Scientific HR coma corrector

Acquisition

- 72 lights x 300 s = 6 h
- no dark, flat, bias frames
- no filters
- ISO 200
- Bortle 4

Processing (latest revision)

- stacked in DSS
- bilinear debayer method & median kappa sigma clipping

- unmodified TIF opened in PixInsight
- STF stretch
- dynamic crop
- dynamic background extraction
- background neutralization
- color calibration
- histogram transformation
- SCNR green to remove greenish noise
- creation of lightness mask that covers most of the galaxy but not the background
- multiscale linear transform to improve detail of brighter galaxy parts
- creation of lightness mask that covers the background only
- (masked) curves transformation to reduce saturation (and therefore color noise) of background
- resample 50% to improve general noise (not much detail loss as the image was oversampled anyway)
- mild ACDNR with maximum "bright sides edge protection" to not lose much of the detail again
- another background neutralization to get rid of a slight redshift I somehow introduced before
- final histogram / curves transformations
- saved as jpg

Comments

Revisions

  • M101 - Pinwheel Galaxy, 



    
        

            Steve Ludwig
    Original
  • M101 - Pinwheel Galaxy, 



    
        

            Steve Ludwig
    B
  • Final
    M101 - Pinwheel Galaxy, 



    
        

            Steve Ludwig
    C

B

Description: In this iteration I added another "Background Neutralization" step right at the end to get rid of a slight redshift in the background.

Uploaded: ...

C

Description: For this revision I added the following steps:

- deconvolution step for the brightest part of the galaxy to increase sharpness
- multiscale linear transform applied to the stars to increase sharpness
- final curves transformation to increase overall color saturation a bit

Uploaded: ...

Sky plot

Sky plot

Histogram

M101 - Pinwheel Galaxy, 



    
        

            Steve Ludwig