ORBITAL EVOLUTION OF A BINARY NEUTRON-STAR AND GRAVITATIONAL-RADIATION

We consider the dependence of the internal structure of a neutron star in a close binary system on the semi-major axis of the binary orbit, focusing on the case when the Roche lobes of the components are nearly filled. We adopt a polytropic equation of state. The temporal evoluti on of the semi-major axis and its dependence on the mass ratio of the binary components and the polytropic index n are determined. The calcu lations are carried out right up to the moment of contact, when the qu asi-stationary model becomes invalid. We analyze differences in the sh apes of the pulses of gravitational radiation emitted by a pair of poi nt masses and by a binary neutron star, taking into account its intern al structure and tidal deformations.