Degenerate Stars

Abstract

When massive stars have exhausted the nuclear fuel in their cores, the latter collapse and squeeze their matter to densities of electron degeneracy, or even neutron degeneracy, whereby the liberated binding energy causes a nova-, or supernova-explosion. The stellar remnants formed at the centers of such explosions are compact, non-burning, degenerate stars, white dwarfs or neutron stars. Their deep potential wells (under accretion) and often high spins and strong magnetic surface fields give rise to all sorts of high-energy processes, among them pair creation,relativistic ejection, hard radiation, and jet formation. Compact binary stars can assemble compact accretion disks around them whose masses may grow comparable in the case of neutron stars (with their low Eddington mass rate), and lead to supersoft X-ray sources, super-Eddington accretion, and to the appearance of black-hole candidates. For a more comprehensive discussion see [Kundt, 1998a].