Professor James B. Kaler
Department of Astronomy
University of Illinois
Planetary nebulae, bright expanding shells of dusty gas that surround hot blue stars, are the ejected envelopes of giant stars whose hydrogen fusion chain has shut down, the central stars the giants' old nuclear-burning cores. Illuminated by photoionization by ultraviolet radiation from the hot core, the nebulae tell us a great deal about the processes that take place in dying stars and are an important interface in the recycling process that mixes enriched stellar matter back into the interstellar medium. The colloquium will give an overview of the subject from discovery through modern advances, focusing on the chemical compositions, structures, and evolution of the nebulae, and on the conditions in the central stars, which are in the process of becoming white dwarfs.
Friday, November 2, 2001 Refreshments at 3:30 p.m.
Bradley Commons, 2202 Everett Tower
Talk at 4 p.m.
1110 Rood Hall