Basri, Gibor AST 96-18439 Dr. Basri will carry out an observational study of the properties of brown dwarfs and very low-mass stars. His study is timely and important in light of the recent discoveries of very low mass companions to other stars. His research plan has 3 primary objectives : 1) to search for brown dwarfs in the Pleiades star cluster and to use them to estimate the brown dwarf mass fraction and to establish the "lithium age" of the cluster in conjunction with stellar models, 2) to explore the relation between rotational velocity and activity in late M stars, and 3) to improve model atmospheres for very cool main-sequence stars through the use of atmospheric diagnostics provided by high- resolution spectroscopy. The proposed array of topics take advantage of the observational facilities at Keck and at Lick, to which the PI has access. ***
