Arp 170 consists NGC 7578 (actually two galaxies - NGC 7578A and NGC 7578B) at the center of the image. These are included in the ‘Galaxies with diffuse counter-tails’ class. Arp 170 along with several galaxies above the center are also members of Hickson 94. These are also part of the larger Abell 2572 galaxy group. Arp 170 is located approximately 525 million light-years away in Pegasus.
Luminance – 24x600s – 240 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
360 minutes total exposure – 6 hours
Imaged September 24th and 25th and December 13th and 18th, 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/39511259885/sizes/l