In the past few years, general astronomical interest has concentrated on s- eral objects and phenomena where white dwarf stars play a key role. T Type Ia supernovae have been used as evidence to show that, in fact, Einstein did not make his greatest blunder when heallowedfor the possibility of a c- mological constant. Improvements in our knowledge of the Hubble parameter have revived interest in the use of white dwarf stars as a different typeofc- mochronometer to measuretheage of the Galaxy andthus set constraints on the age of the Universe. In roughly the same time period, there have been considerable advances in our understanding of white dwarf stars, both as i- lated stars in the ?eld and as members ofinteracting binary systems. Much of thisadvance has come from theavailabilityof spacecraftobservations from missions like HST T T, IU UE, ROSAT T, EXOSAT T, Chandra, ORFEUS, EUVE, HUT T T, and FUSE. The discovery of thousandsof new white dwarfs from a number oflarge surveys and thepotential of theSloan Digital SkySurvey have added impetus to the ?eld. Studies ofinteracting binaries such as classical novae, supersoft X-ray bi- ries, symbiotic variables, dwarf novae and nova-like objects have revealed the diff ferences between thethermal evolution of singleand close binary systems aswell as heightenedinterest in these systems as progenitors of the cosmol- ically important Type I supernovae. A more speculative question is whether classical novae can beunderstood well enough that theymight provide another kind of standard candle.
About the Author:

Edward M. Sion, Professor of Astronomy and Astrophysics, Villanova University, Former Scientific Editor, The Astrophysical Journal, author or co-author of over 400 scientific publications on white dwarfs and cataclysmic variable stars, co-author of the Catalogue of Spectroscopically Identified White Dwarfs.

Stephane Vennes, Research Astronomer, Johns Hopkins University, Lecturer, Australian national University, leading expert on the physics of diffusion, radiative forces, and accretion onto white dwarfs, and specialist on space ultraviolet studies of white dwarf stars.

Harry L. Shipman, Annie Jump Cannon Professor of Astronomy, University of Delaware, Distinguished Educator Medal, the National Science Foundation, author or co-author of over 300 scientific publications on white dwarfs and author of Black Holes and the Infinite Universe and Introductory Astronomy, leading expert on white dwarf stars and science education.