White Dwarfs

(astronomy), very dense small hot stars consisting of degenerate gas. The mass of an ordinary white dwarf averages about 1, the radius about 0.2, and the luminosity about 0.01 of the corresponding values of the sun. The average density of a white dwarf ranges from 10⁴ to 10⁶ g/cm³. The first white dwarf, a satellite of Sirius (a white star 10,000 times fainter than Sirius), was discovered from the distorted movements of the main star caused by attraction of the satellite. The discovery of dwarf stars confirmed the physical theory which holds that the size of bodies of degenerate gas is inversely proportional to their mass. Dwarf stars are considered the final stage in the evolution of ordinary stars after exhaustion of the thermonuclear sources of energy. They may also be related to pulsars.