The physics of white dwarfs

White dwarf stars, so called because of the color of the first few to be discovered, occupy a key position in astrophysical theory. Together with neutron stars and black holes, they are the terminal points of stellar evolution. Their properties thus provide clues to the physical processes that take place during the rapid and often spectacular evolutionary stages near the ends of stellar lifetimes. In addition, white dwarfs provide astrophysical “laboratories” for “measuring” the physical properties of matter under extreme conditions. These extend from conditions like those in laser-produced plasmas to those typical of the solid crusts of neutron stars. White-dwarf stars also occur as components of cataclysmic binary systems—novae, dwarf novae and related objects—and knowledge of the properties of white dwarfs is essential to the development of satisfactory theoretical models for these systems.