RAPID BINARY STAR EVOLUTION FOR N-BODY SIMULATIONS AND POPULATION SYNTHESIS

We present an algorithm for the rapid evolution of binary stars, It is based on simple fitting formulae for the evolution of single stars, M ass loss, mass transfer and common-envelope evolution are followed wit h the changes to both the mass donor and the accretor where applicable , We describe a procedure for integrating our formulae and give exampl es of how we can follow the evolution of Algols and cataclysmic variab les. The algorithm can be used for simple binary population synthesis, We also explain how we incorporate it into N-body simulations where w e introduce a new scheme that deals with colliding stars.