The influence of radiation pressure on equipotential surfaces in high-temperature binary systems

In this paper we considered the effect of the radiation pressure from both components of the high-temperature binary systems in terms of a modified Roche potential. Usually, the parameters of radiation pressures ₁, ₂ can be written as a function of radiiR, effective temperatureT _eff , and massM of components. The simulation calculation shows that the positions of saddle pointsL ₁ ,L ₂ ,L ₃ and shape of critical surface are changed with radiation pressure factors ₁, ₂. Consequently, use of the conventional critical Roche model to estimate value of radii and mass ratios may be completely unwarranted if effective temperature of both componentsT _eff 30 000 K.These conclusions are applied to Wolf-Rayet binary systems V444 Cygni,v ₂ Velorum, and O-type binary system Y Cygni. The modified critical potentials are calculated and discussed.