THE EFFECT OF ANGULAR-MOMENTUM EXCHANGE IN THE EVOLUTION OF BINARY-SYSTEMS

The evolution of a binary system consisting of a 8M. and 5.5M. star ha s been studied in the conservative approximation of Case B mass transf er. Specific attention is given to the effect of exchange between the orbital angular momentum and the spin angular momentum as the primary component evolves to a red giant and in the phase of mass transfer. It has been found that the system considering the spin angular momentum will evolve to a longer orbital period and with a smaller endmass of t he primary. It shows that the spin angular momentum cannot be neglecte d in the calculating of the evolution of binary systems.