Hickson 81 consists of PGC 57777, 2MASX J16181406+1247202, 2MASS J16181481+1247361 and 2MASX J16181367+1248108. These appear to be collectively cataloged as UGC 10319, too. These are located at an unknown distance in Hercules.
Luminance – 24x600s – 240 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
360 minutes total exposure – 6 hours
Imaged June 10th, 17th and 18th, 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/50130294998/sizes/l/