NGC 3748

NGC 3748 is a lenticular galaxy with a bar located in the Leo constellation. It is located 440 million light-years away from the Solar System and was discovered by Ralph Copeland on April 5, 1874, but also observed by Hermann Kobold, Lawrence Parsons and John Louis Emil Dreyer. Like NGC 3746, NGC 3748 also has a recessed core (RET). It is described as, "moderately bright, fairly small, slightly elongated NW-SE, 0.4'x0.3' with a small bright core".

Copeland Septet
NGC 3748 is a member of the Copeland Septet which is made up of 7 galaxies which were discovered by Copeland in 1874. The other members are NGC 3745, NGC 3746, NGC 3750, NGC 3751, NGC 3753 and NGC 3754.

Halton Arp noticed the galaxies in this group in an article that was published in 1966. This group is known as Arp 320 along with another galaxy, PGC 36010.

This group was observed by Paul Hickson whom he included in his article in 1982. The group is known as Hickson 57, in which NGC 3748 is designated as HCG 57E.