To date, a non-redshift measurement gives a distance of approximately 138,000 Mpc (450 million light-years) for NGC 3751. This value is within the Hubble Distance values.[5]
Halton Arp noticed the 7 galaxies in which he published inside his article in 1966.[8] This group is known as Arp 320 in which another galaxy, PGC 36010 is part of it.[9]
This group was also observed by Paul Hickson, in which he included them inside his article which was published in 1982.[10] It is noted that this group is designated as Hickson 57. NGC 3751 is known as HCG 57F.[11]