Like NGC 3746, NGC 3748 also has a recessed core (RET).[4] It is described as, "moderately bright, fairly small, slightly elongated NW-SE, 0.4'x0.3' with a small bright core".[6]
Halton Arp noticed the galaxies in this group in an article that was published in 1966.[9] This group is known as Arp 320 along with another galaxy, PGC 36010.[10]
This group was observed by Paul Hickson whom he included in his article in 1982.[11] The group is known as Hickson 57, in which NGC 3748 is designated as HCG 57E.[12]