THE EFFECT OF STELLAR WIND ON THE STABILITY OF TRIPLE-SYSTEMS

The dynamical evolution of hierarchical triple systems is considered. The effects of mass loss via stellar wind on the stability of triple s ystems, with respect to violation of the hierarchical structure and es cape of the distant component without exchange, are studied. Plane tri ple systems with initially circularly orbiting inner and outer binarie s are investigated. The directions of the revolutions of both binaries coincide. Triple systems with main-sequence components, and also thos e with red giants, are considered. It is shown that in both cases ther e is an increase in the stability of the triple systems with respect t o violation of the hierarchical structure. A trend towards stability l oss, with respect to the escape of the distant component without viola tion of hierarchy, is present only in the case when the mass of this c omponent is less than the combined masses of the binary system compone nts. The typical times over which the stability measures vary are comp arable with the evolutionary times. The effects of stellar wind on the stability of triple systems with respect to violation of the hierarch y can be estimated analytically, using the representation of the tripl e system as a superposition of two binaries. As for stability with res pect to the escape of the distant component which has not undergone pr evious exchange, the analytical results are an overestimate.