06/04/2026
Thanks to peter Fletcher for this beautiful photo of Bode's Galaxy.
Bode’s galaxy. Discovered by the German astronomer Johann Elert Bode in 1774, M81 is one of the brightest galaxies in the night sky. It is located 11.6 million light-years from Earth in the constellation Ursa Major.
The galaxy’s spiral arms, which wind all the way down into its nucleus, are made up of young, bluish, hot stars formed in the past few million years. They also host a population of stars formed in an episode of star formation that started about 600 million years ago. Ultraviolet light from hot, young stars is fluorescing the surrounding clouds of hydrogen gas. A number of sinuous dust lanes also wind all the way into the nucleus of M81.
The galaxy’s central bulge contains much older, redder stars. It is significantly larger than the Milky Way’s bulge. A black hole of 70 million solar masses resides at the center of M81 and is about 15 times the mass of the Milky Way’s central black hole. Previous Hubble research showed that the size of the black hole in a galaxy’s nucleus is proportional to the mass of the galaxy’s bulge.