Messier 81
| Messier 81 | |
|---|---|
The HST's view of M81, with its open star clusters, globular star clusters, and regions of fluorescent gas. | |
| Observation data (J2000 epoch) | |
| Constellation | Ursa Major |
| Right ascension | 09h 55m 33.1730s |
| Declination | +69° 03′ 55.060″ |
| Redshift | 0.000130±0.00000900 |
| Heliocentric radial velocity | −39±3 km/s |
| Galactocentric velocity | 73±6 km/s |
| Distance | 11.99 ± 0.16 Mly (3.675 ± 0.049 Mpc) |
| Apparent magnitude (V) | 6.94 |
| Surface brightness | 22.78 (B) |
| Characteristics | |
| Type | SA(s)ab, LINER |
| Size | 29.44 kiloparsecs (96,000 light-years) (diameter; 25.0 mag/arcsec2 B-band isophote) |
| Apparent size (V) | 26.9′ × 14.1′ |
| Other designations | |
| Bode's Galaxy, IRAS 09514+6918, NGC 3031, UGC 5318, MCG +12-10-010, PGC 28630, CGCG 333-007 | |
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 D25 isophotal 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.