The Principal Investigator intends to do research on the class of short-period Algol-type binaries to study the effects of the impact of a gas stream from the companion star onto the surface of the accreting star. This process is known as the star-stream interaction. This study will encompass both observational and theoretical work. In the first case, the properties of the circumstellar material which results from the star-stream interaction will be obtained from an analysis of observations of the H alpha line profile of several binaries. While in the latter case, extensive numerical hydrodynamical calculations will be make to determine the expected character of the impact region and any other circumstellar material which might result from the impact. The National Observatories and National Supercomputing Centers will be used for this research. This work is important because it will show how the evolution of a star is influenced by its membership in a close interacting binary, like the short-period Algol-type binaries.//
