Previous abstract Next abstract

Session 33 - Neutron Stars & White Dwarfs.
Oral session, Monday, January 15
Salon del Rey South, Hilton

[33.02] WFPC2 Photometry of the Bright, Mysterious White Dwarf Procyon B

J. L. Provencal, H. Shipman (U. Delaware)

Procyon B is one of a handful of white dwarf stars which are in visual binary systems. We have accurate measurements of the binary period, and hence, of the white dwarf's mass. Procyon B represents a critically important object for testing the fundamental physics of stellar degeneracy. However, the separation between primary and secondary is too close to allow accurate ground-based determinations of basic characteristics, such as temperature and chemical composition, which would allow us to derive its radius. Furthermore, since the age of this system is known, if we can determine Procyon B's temperture, we can determine the mass of its progenitor and provide a stringent test for theories of stellar mass loss. We present the results of WFPC2 data, from which we determine a spectral type of DA, an apparent magnitude of \rmM_V=10.75, and an effective temperature of 8000\pm400 K. The stellar radius derived from these parameters lies on the mass-radius relationship for white dwarfs.

Program listing for Monday