Evolution in Binary and Triple Stars, with an application to SS Lac

摘要: We present equations governing the way in which both orbit and intrinsic spins of stars a close binary should evolve subject to number perturbing forces, including effect third body possibly inclined wider orbit. illustrate solutions some binary-star triple-star situations: tidal friction wide but eccentric radio pulsar about B star, Darwin eccentricity instabilities more massive shorter-period X-ray binary, interaction with Kozai cycles triple such as Algol (beta-Per), at an early stage that star's life when all 3 components were ZAMS stars. also attempt model detail interesting system SS Lac, stopped eclipsing 1950. find our Lac is quite constrained by relatively good observational data this system, leads specific inclination (29 deg) outer relative inner epoch zero (1912). Although have little on orbit, converse not true: spin axes can vary their orientation up 120 deg timescale century.