2002ApJ...577L..39D

Using WIYN/Hydra observations, we report the first discovery of a super-Li-rich dwarf, the star J37 of the Hyades-aged cluster NGC 6633. This star's gargantuan surface Li abundance of A(Li)=4.29±0.07 [A(X)≡12+log(N_X/N_H)] is a factor of 10 larger than the Li abundances observed in meteorites and in minimally depleted young open cluster stars. J37 may be the smoking gun for the action of diffusion, models of which predict the existence of striking Li overabundances due to radiative acceleration (the ``Li peak'') in the extremely narrow T_effrange of 6900-7100 K. The low-C, high-Fe, and higher Ni abundances in J37 also support the diffusion model, although other elemental abundances do not agree as well with the model predictions. We have discounted other Li-enrichment scenarios (spots, asymptotic giant branch contamination, planetesimal accretion). While slow mixing seems to be the universally dominant Li-depleting mechanism during the main-sequence evolution of F, G, and K dwarfs, the F dwarf J37 illustrates that Li diffusion can occur in solar-type stars under the right circumstances.