M81 Group

The M81 Group is a nearby collection of galaxies centered on Messier 81. It includes the starburst galaxy Messier 82 and numerous dwarf galaxies.

Messier 81: Messier 81 is a grand-design spiral galaxy in the constellation Ursa Major. It is the group’s dominant galaxy and namesake.
Galaxy interaction: A galaxy interaction is a gravitational encounter that alters the structure or evolution of one or more galaxies. Repeated encounters among the group’s large galaxies produced visible distortions and debris.
M81–M82 interaction: The M81–M82 interaction is a gravitational encounter between two nearby galaxies in the M81 Group. It connects the group’s best-known spiral galaxy with its starburst companion.
Local Volume: The Local Volume is the nearby region of the universe, extending roughly 10 megaparsecs around the Local Group. The M81 Group is one of the prominent galaxy groups in this nearby region.
Messier 82: Messier 82 is a nearby starburst galaxy with intense star formation and prominent galactic outflows. Its close passage by Messier 81 helped trigger its starburst.
Tidal tail: A tidal tail is an elongated stream of stars and gas pulled from a galaxy by gravity. Tidal tails and bridges trace material drawn between interacting group members.
M81 Group tidal streams: M81 Group tidal streams are extended structures of stars and gas stripped from interacting galaxies. They reveal how encounters have rearranged matter across the group.
Local Group: The Local Group is the galaxy group containing the Milky Way, Andromeda, and their satellite galaxies. It is a nearby counterpart for comparing group membership and galaxy evolution.
NGC 3077: NGC 3077 is a dwarf galaxy in Ursa Major, interacting with Messier 81. Its tidal debris forms part of the group’s shared gas structures.
Starburst galaxy: A starburst galaxy forms stars at a rate far above the typical rate for galaxies of similar mass. The group’s interactions are associated with Messier 82’s unusually intense star formation.

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IC 342/Maffei GroupCompared with: It is a separate neighboring group used to compare nearby galaxy environments.