White Dwarfs

Abstract

It is characteristic for configurations involving degenerate matter that mechanical and thermal properties are more or less decoupled from each other. Correspondingly we will discuss these two aspects separately. When dealing with the mechanical problem (including the P and ϱ stratification, the M-R relation, etc.) one may even go to the limit T → 0. Of course, such cold matter can not radiate at all and it is more appropriate to denote these objects as “black dwarfs”. The thermal properties, on the other hand, are responsible for the radiation and the further evolution of white dwarfs. The evolution indeed leads from a white dwarf (WD) to a black dwarf, since it is — roughly speaking — the consumption of fossil heat stored in the WD which we see at present. (Concerning the evolution to the white-dwarf stage see §§33,34.)