24 Sept 2026
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.
M81
20 credit
Filtro | Exp. media (s) | Esposizione totale | Sottoframe |
|---|---|---|---|
| Luminance | 1705 | 9h | 19 |
| Red | 758 | 4h | 19 |
| Green | 758 | 4h | 19 |
| Blue | 800 | 4h | 18 |
| Halpha | 1800 | 9h | 18 |