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 and has an apparent magnitude of 6.9. Through a pair of binoculars, the galaxy appears as a faint patch of light in the same field of view as M82. A small telescope will resolve M81’s core. The galaxy is best observed during April.
This stunning image shows 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. 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.
Around the galaxy’s center, young stars are being born 10 times faster than they are inside our entire Milky Way galaxy. Radiation and energetic particles from these newborn stars carve into the surrounding gas, and the resulting galactic wind compresses enough gas to make millions of more stars. The rapid rate of star formation in this galaxy eventually will be self-limiting. When star formation becomes too vigorous, it will consume or destroy the material needed to make more stars. The starburst will then subside, probably in a few tens of millions of years.
It's companion in the image is the Cigar Galaxy (M82) which was also discovered by Johann Elert Bode in 1774. Located 12 million light-years from Earth in the constellation Ursa Major, M82 has an apparent magnitude of 8.4 and is best observed in April. Although it is visible as a patch of light with binoculars in the same field of view as M81, larger telescopes are needed in order to resolve the galaxy’s core.
Edition limited to a run of 50 giclee prints.
Exterior Frame 39.5 x 23.5 inches.
Print Size 21.75 x 15.75 inches.
Image Size 17.75 x 12 inches