Polarization of thermal radiation from accretion disks in dwarf novae

Theoretical calculations of linear polarization of thermal radiation from accretion disks in nova-like variables and dwarf novae in eruption are presented. The primary source of polarization is due to electron scattering in the disk's photosphere. It is shown that the degree of polarization can be used as a powerful probe of the structure and evolution of the disk atmosphere. The degree of polarization is considerably higher in the ultraviolet than at optical wavelengths, and the degree of polarization may be higher in an eclipsing system when the central region of the disk is eclipsed. The orbital phase dependence distinguishes intrinsic polarization from the disk to that due to interstellar medium.