Paul Hickson conducted a systematic search to identify groups of galaxies. To qualify for inclusion into a group, at least four reasonably compact and isolated member galaxies must be identified. Hickson presented his catalog of 100 galaxy groups in 1981.
The image above is number 61 in Hickson's Atlas of Compact Groups of Galaxies, commonly referred to as HCG 61, is located in the constellation Coma Berenices. The group contains four galaxies that form a rough rectangle and have been named The Box. Studies of the group have determined the bluish edge on spiral galaxy (upper right corner) is not associated with the remaining 3 galaxies. This galaxy (NGC 4173) is approximately 43 million light years distant while the other 3 reside some 170 million light years away. The designations and relative location of the member galaxies may be view here.
1https://www.deepskycorner.ch/hcg61/hcg61.en.php