Effect of the radiation pressure on the dimensions of the primary component of the binary system of the stars

Abstract

In this dissertation, we have studied the dimensions of the primary component of the binary system of the stars under the effect of radiation pressure using the methodology of Kopal (1959) and modified Roche potential as given by Schuerman (1972). Kopal (1959) introduced the concept of Roche potential to analyse various problems of the rotating stars and stars in the binary systems. Using the concept of Roche potential, author also studied the dimensions and other parameters of the binary system of the stars. However, the Roche potential that has been used in these studies consist of only gravitational and centrifugal forces, whereas, the forces like radiation pressure has not been considered. It has been observed that during certain stages of evolution of the binary stars, the effect of radiation pressure becomes significant and affects the shapes of the stars, binary configuration and the mass flow. While studying the effect of radiation pressure on the shapes of the stars in close binary systems, Schuerman (1972) obtained an expression for the modified Roche potential that takes into account the effect of radiation pressure from the primary component of the binary system. In the present work, we have used the modified expression of Roche potential as given by Schuerman (1972) and utilized the methodology of Kopal (1959) to determine the effect of radiation pressure on the dimensions of the primary component of the binary system of the stars. Thesis consists of 2 chapters. Chapter I is preliminary in nature. In this chapter, literature survey, Roche potential and methodology of Kopal (1959) (to obtain the dimensions of the primary component and certain other parameters of the binary system of the stars) has been discussed. In chapter II, the modified Roche potential as given by Schuerman (1972) that incorporates the effect of radiation pressure has been used along with the methodology of Kopal (1959) to obtain the modified expression for the dimensions of the primary component and certain other parameters of the binary system of the stars. The numerical results has been then obtained for various models of the stars in the binary system and finally certain conclusions has been drawn.