Donald Edward Osterbrock (July 13, 1924 – January 11, 2007) was an American astronomer, best known for his work on star formation and on the history of astronomy.
His work there with William Wilson Morgan and Stewart Sharpless showed the existence of the Milky Way's spiral arms.
[2] In 1973 he moved from Madison to the University of California at Santa Cruz, as Professor of Astronomy and Astrophysics, and Director of Lick Observatory, a position he held until 1981.
Thereafter, Emeritus Professor Osterbrock continued to make daily trips to his office on campus, to work on his research, to keep publishing, and to maintain an active role in the astronomical community.
Osterbrock's research included work on the nature of ionized gases around hot stars and studying active galactic nuclei powered by black holes.