Arp 263 (NGC 3239, UGC 5637, PGC 30560, VV 95 and others) is an irregular galaxy approximately 29.75 million light-years away in Leo. Arp has this one in his ‘Irregular Clumps’ class. Probably the result of the merger of a couple galaxies in the past, this one was discovered by William Herschel March 21, 1784. There’s a good paper on the structure of this galactic train wreck here - http://articles.adsabs.harvard.edu/full/1990PASP..102...41K. Thanks go to mentor Rick Johnson (https://www.mantrapskies.com/) for pointing out the paper.
Luminance – 24x600s – 240 minutes – binned 1x1
RGB – 12x300s – 60 minutes each – binned 2x2
420 minutes total exposure – 7 hours
Imaged January 18th and 22nd, 2020 from Dark Sky New Mexico at Rancho Hidalgo (Animas, New Mexico) with a SBIG STF-8300M on an Astro-Tech AT12RCT at f/8 2432mm.
LRGB - https://www.flickr.com/photos/dcrowson/50662250398/sizes/l/
LRGB annotated - https://www.flickr.com/photos/dcrowson/50662250548/sizes/l/