The topic of interacting binary star systems has become a nexus of stellar astrophysics, searching as a bridge between traditional studies of the evolution of single stars and the newer areas that include the evolution of accretion disks around companions to expanding stars as well as of episodic "mass losers," such as B-emission and cataclysmic variable stars. In this two-year proposal, the Principal Investigator and his collaborator, Dr. P. Etzel of San Diego State University, will continue a program of simultaneous monitoring of interacting binaries that include an evolving hot star ("Algol systems"). They will carry out observations at the 1-meter telescope of Mt. Laguna Observatory outside of San Diego. They will use this facility in a dual mode, monitoring light and spectral variations nearly simultaneously as these stars orbit around one another every few days. They will compare these data obtained throughout the orbital period for each star with models of accretion disks the PI has computed in which "non-LTE" effects are included.
