AST 101 Lecture Notes - Lecture 18: Accretion Disk, Binary Star, Star System
Document Summary
Everything i"ve had to say about stellar evolution has been in the context of single stars. But, as you may recall, most stars are in multiple star systems (binaries, triples, and so forth). Yes, it can, and sometimes does so dramatically. The closer the two stars of a binary are to one another, the greater the effects on their evolution. If one considers the masses and separations of the stars, one can construct a map of the gravitational potential of the system. The contours in the plot are lines of equal gravitational potential. If matter from either star gets to the point labelled l1, it can be transferred to the other star. In close binaries, the stars are near enough to one another than the more massive star (and thus the first to begin evolving into a red giant) can shed material onto the less massive star. The technical term is that the evolved star overflows its roche lobes.
