White dwarf stars are the endpoint of evolution for solar-like stars. They are inert cinders of nuclear ash, about the size of the Earth, but with the mass of a star. They generate no energy; they merely cool off with time. In isolation, they are among the least interesting objects in the universe.
However, in close binary star systems they are known as cataclysmic variables and dwarf novae. They are the only low mass stars that can explode, and that they do, both as classical novae and as type Ia supernovae. I shall discuss the astrophysics of white dwarfs, from their boring existence as single stars to the explosive consequences of mass transfer in a close binary star system.
Prof. Walter, a resident of East Setauket, studies star birth, stellar weather, and star death using the Chandra and XMM-Newton X-ray observatories, the Hubble Space Telescope, and telescopes in Arizona, Hawaii and Chile. He has been a professor of Astronomy at Stony Brook since 1989.