Contains:Merope nebula, NGC 1435, Maia nebula, NGC 1432, The star Pleione (28Tau), The star Atlas (27Tau), The star ηTau, The star Merope (23Tau), The star Sterope I (21Tau), The star Taygeta (19Tau), The star 18Tau, The star Electra (17Tau), The star Celaeno (16Tau)
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M45 Pleiades LRGB, Bortle 9 skies, 


        Chad Andrist
M45 Pleiades LRGB, Bortle 9 skies

M45 Pleiades LRGB, Bortle 9 skies

Technical card

Resolution: 1800x1344

Dates: Dec. 19, 2017

Frames: 210x38"

Integration: 2.2 hours

Avg. Moon age: 1.08 days

Avg. Moon phase: 1.32% job: 1875576

RA center: 56.739 degrees

DEC center: 24.128 degrees

Pixel scale: 3.765 arcsec/pixel

Orientation: 269.616 degrees

Field radius: 1.175 degrees

Locations: Home, Milwaukee, Wisconsin, United States

Data source: Unknown


I prefer getting out to darker skies when doing LRGB, but right now things are not conducive to doing so. M45 is an easy object to nab from light polluted skies, although I was very surprised at how much nebulosity I was able to grab. Not too shabby!

Posted image is a crop to remove vignetting

ASI1600MMC, -15C, Gain 139/Offset 21 (Unity)
L 60x30s
R 36x60s, 14x30s
G 36x60s, 14x30s
B 36x60s, 14x30s



Chad Andrist
License: None (All rights reserved)


  • M45 Pleiades LRGB, Bortle 9 skies, 


        Chad Andrist
  • Final
    M45 Pleiades LRGB, Bortle 9 skies, 


        Chad Andrist


Completely reprocessed in PI from integration forward because I didn't like how the stars turned out. Closer examination revealed that the high sigma clipping was a bit too aggressive and was chomping off the tops of my stars. The stars in my LUM stack had halos around everything, so I tried creating a superlum and it helped mitigate things. My stack came out cleaner, so I didn't have to crop as much to eliminate vignetting, and I also darkened the background less so just a hint of the surrounding nebulosity shines through.

Sky plot

Sky plot


M45 Pleiades LRGB, Bortle 9 skies, 


        Chad Andrist