NGC 6255 (UGC 10606, PGC 59244 and others) is a low surface brightness (LSB) galaxy located approximately 59 million light-years away (https://iopscience.iop.org/article/10.3847/0004-6256/152/2/50/pdf) in Hercules.
Luminance – 24x600s – 240 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
360 minutes total exposure – 6 hours
Imaged May 25th, 26th and 27th and June 7th and 9th, 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/50007279161/sizes/l/