NGC 891 (Caldwell 23, UGC 1831 and others) is an edge-on unbarred spiral galaxy located approximately 30 million light-years away in Andromeda.
Luminance – 24x600s – 240 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
360 minutes total exposure – 6 hours
Imaged September 8th and 23rd, 2016 from 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/29609294950/sizes/l