Bode’s Galaxy

Bode's Galaxy (M81, NGC 3031), is located in the constellation Ursa Major and is about 12 million light-years from Willingboro, NJ. It is about 90,000 light-years in diameter (half the size of the Milky Way).

It was discovered by the German astronomer Johann Elert Bode in 1774, and is one of the brightest galaxies in the night sky. And it is the most remote blue-shifted large galaxy known.

The galaxy’s spiral arms are made up of young, bluish, hot stars formed in the past few million years along with slightly older 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 densely-packed center contains much older, redder stars. A black hole of 70 million solar masses resides at the center of M81. All told, it is home to over 250 billion stars.