Evolution of the Lithium Abundance of Solar-Type Stars. X. Does Accretion Affect the Lithium Dispersion in the Pleiades?

Sixteen G and K dwarfs in the Pleiades cluster were analyzed for evidence that accretion of hydrogen-depleted planetesimals has contributed to the lithium dispersion observed in cluster stars of similar effective temperature. The HiRes spectrograph on the Keck 10 m telescope was used to obtain spectra of slowly rotating Pleiades stars having similar effective temperatures but different lithium abundances. The high-resolution echelle spectra were analyzed for a possible dispersion in the metal abundances correlated with the observed dispersion in lithium abundance. The existence of such a correlation would support the possibility that young stars can replenish their surface lithium by accreting hydrogen-depleted material from a circumstellar disk. The narrow dispersion in the metal abundances of the observed stars makes it unlikely that accretion plays a role in the dispersion in lithium abundances.