Super Soft Sources
  The class of Super Soft Sources has been established after discoveries performed with the Einstein and the ROSAT satellite. Only sources contributing to the class of super-soft X-ray binaries are considered. The X-ray emission in these sources is due to thermonuclear burning of accreted material on the surface of a white dwarf. The physical process of nuclear burning is described. The typical timescales of variability in these sources are discussed. The appearance and modeling of supersoft X-ray spectra are described. The phenomena related to the accretion disk in these sources are outlined. A discussion of the nature and appearance of the donor star is given. The evolutionary state of these sources and their likely progenitorship for Type Ia supernovae is shortly outlined. A summary of recent discoveries with Chandra and XMM-Newton of super-soft sources in nearby spiral and elliptical galaxies is given. 
P. Kahabka (Univ. of Bonn)