A model atmosphere investigation of the effects of irradiation on the secondary star in a dwarf nova

Abstract

We compute some exploratory model atmospheres and synthetic spectra for red dwarfs which incorporate the phenomena of irradiation. These models are suitable for studies of the secondary stars of the shorter period dwarf novae. Our models show that the incident flux produces marked changes in the temperature stratification and emitted spectra of the irradiated star. We investigate the effects of angle of incidence and, in an approximate manner, those of horizontal energy transfer. The latter factor has a particularly strong effect on our results. Our results have important implications for the interpretation of radial-velocity curves of dwarf novae.