A nice group of galaxies in constellation Coma Berenices.

While the bluish NGC 4173 is relatively near by („only“ about 50 million light years away), the other three galaxies belong together and are located about 169 to 180 million light years in the background. They are part of a much larger group of galaxies not visible in this frame.

The Hickson Compact Group catalogue was new to me. It was compiled by Paul Hickson, a British-Canadian astronomer, in 1982 and contains relatively bright compact galaxy groups with at least 4 members.

Fun fact: there is also NGC 4170 in this image, which is however usually classified as a star and sometimes confusingly identified with NGC 4173. I guess it was originally mistaken as a nebulous object and therefore ended up in the New General Catalogue (NGC).

Celestron EDGE HD8 at Prime Focus F=2080mm, F/10
Skywatcher EQ6R Pro mount
ASI2600mc Pro
No filter
Bortle 4-5
94x300sec (7h50m)

PixInsight