Abundances of Lithium and Beryllium in some F Dwarfs and K Giants.

We have determined the Li and Be abundances in ten F dwarfs and two K giants. The analysis was made using equivalent widths and line strengths predicted from a grid of model atmospheres. Curve-of-growth effects were accounted for in an empirical fashion. We find, for the F dwarfs, a large range in the Li overabundances, from a factor 100 to less than 10 tii~ies the solar value. The Be abundances are similar to the solar value but differ from it in several stars. The Li/Be ratio ranges from about 75 to near unity. It is doubtful that errors in the analysis could account for all this difference. Our Li/Be results, when combined with those for G dwarfs studied by Merchant (Astrophys. J. 143, 336, 1966), suggests Li depletion occurs in main-sequence stars of type F and later. In addition to the above evidence, since some of these stars contain Li6, this depletion must be on a "long time scale" so that both Li6 and Li7 can be affected at the same rate. There is at present some uncertainty in the expected Li/Be production ratio by spallation. Of the two K giants studied, CL Boo has no detectable Li or Be, so the ratio is unknown. p Gem has much less Li than the sun but about the same Be abundance. This evolved star represents a clear case of depletion of Li but not of Be.