M103 (NGC 581 and others) is a trumpler (https://en.wikipedia.org/wiki/Trumpler_classification) class II 2 m open cluster located approximately 10,000 light-years away in Cassiopeia.
Luminance – 12x300s – binned 1x1 – 60 minutes
RGB – 8x180s – 24 minutes each – binned 2x2
132 minutes total exposure – 2 hours 12 minutes
Imaged November 23rd, 2017 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/37945437404/sizes/l