Boss, Alan AST 96-16093 Recent observational evidence indicates that stars form in pairs, or as binary systems, rather than singly, like our sun. Conditions required to form binary stars are poorly understood, and most theoretical modeling has concentrated on studying single star formation. Dr. Boss will rectify this situation by carrying out research into the processes that lead to binary star formation. His program will improve understanding of the fragmentation process which occurs during protostellar collapse in molecular clouds, and his theoretical models will include effects such as mass accretion, orbital mergers and initial magnetic fields, all previously neglected in theoretical treatments, but recognized to be potentially important. His work will follow the orbital evolution of the binary fragments for much longer times than is typical in models, as the fragments interact with the residual disk and cloud envelope. Dr. Boss's work is closely tied to observations, both through the initial conditions of his models and through the resulting calculation of line emission from the protostellar fragments for comparison with observations of star-forming regions. His results will also allow the determination of the minimum mass of a protostellar fragment, which has bearing on the discrimination between brown dwarf stars and giant planets, and the interpretation of recent observational detection of companions to solar-type stars. ***
