Messier 81 (also known as NGC 3031 or Bode’s Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D₂₅isophotal diameter of 29.44 kiloparsecs (96,000 light-years). Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M_☉ supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy’s large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.

Messier 82 (also known as NGC 3034, Cigar Galaxy or M82) is a starburst galaxyapproximately 12 million light-years away in the constellation Ursa Major. It is the second-largest member of the M81 Group, with the D₂₅ isophotal diameter of 12.52 kiloparsecs (40,800 light-years).