NGC 3751

NGC 3751 is a type E-S0 lenticular galaxy located in the Leo constellation. It is located 450 million light-years away from the Solar System and was discovered by Ralph Copeland on April 5, 1874.
To date, a non-redshift measurement gives a distance of approximately 138,000 Mpc for NGC 3751. This value is within the Hubble Distance values.

Copeland Septet

NGC 3751 is a member of the Copeland Septet. The other members are NGC 3745, NGC 3746, NGC 3748, NGC 3750, NGC 3753 and NGC 3754.
Halton Arp noticed the 7 galaxies in which he published inside his article in 1966. This group is known as Arp 320 in which another galaxy, PGC 36010 is part of it.
This group was also observed by Paul Hickson, in which he included them inside his article which was published in 1982. It is noted that this group is designated as Hickson 57. NGC 3751 is known as HCG 57F.