NGC 3921 is an interacting galaxy in the northern constellation of Ursa Major.

Estimates using redshift put it at about 59 million light years (18 megaparsecs) from Earth.

[3] It was discovered on 14 April 1789 by William Herschel,[6] and was described as "pretty faint, small, round" by John Louis Emil Dreyer, the compiler of the New General Catalogue.

[8] The image shows noticeable star formation and structures like loops, indicative of galaxies interacting.

[5] They are both fairly young, and about half as massive as Omega Centauri, demonstrating that mergers of gas-rich galaxies can also create more metal-rich globular clusters.