Accretion and Explosion: the Astrophysics of Degenerate Stars
Coordinators: Lars Bildsten, Rosanne Di Stefano, Robert Kirshner, John Craig Wheeler
This program concentrates on the astrophysics of accretion and explosions on white dwarfs. Though there is agreement that a Type Ia supernovae originates from a thermonuclear instability of a massive white dwarf, the astrophysical scenario remains ambiguous, as does the mode and outcome of the explosion. The medium redshift supernovae surveys are now providing important clues about the environment dependence of supernovae properties, such as spectra and light curves. These will clearly impact empirical methods that have been developed for using the observed properties of these exploding white dwarfs as distance indicators that are widely applied to determine cosmological parameters.
The time is now ripe to pursue the astronomical origins of Type Ia supernovae and their present-day accreting counterparts, the physical processes that lead to increased mass of the degenerate star in a binary pair, the approach to ignition and explosion mechanisms, the production of the light curve and spectrum, and the nucleosynthetic yield. These theoretical efforts will be accelerated by the large amount of data on the supernovae, their accreting progenitors, and their constantly cooling brethren, the isolated white dwarfs. Our aim is to provide a rich environment for the proper understanding of these phenomena in terms of stellar evolution, the physics of mass transfer binaries, and the physics of thermonuclear supernovae.
There will be a conference associated with this program the week of March 19-23.