Structure of the accretion disk of the dwarf nova WZ Sagittae

The spectroscopic observations of the dwarf nova WZ Sge in May 1994 are pre sented. An analysis of the dependence of the degree of asymmetry of the H-a lpha emission profile on orbital phase has revealed two bright spots on the accretion disk in the system. Their positions are determined. We obtain th e accretion-disk parameters and the phase dependence of the spot luminositi es by modeling the H-alpha profiles. The size of the H-alpha emission regio n is estimated. Its comparison with other data indicates that the radius of the accretion disk in WZ Sge decreases during the outburst cycle (32.5 yea rs) by about 15%. Doppler tomography was used to ascertain the structure of the accretion disk and show that the secondary component also contributes to the H-alpha emission.