Talk

Collerations Between Lithium Depletion and Stellar Spindown for F-Dwarfs and at Higher Mass

Constantine Deliyannis, Indiana University

In Standard Stellar Evolution Theory, depletion of the surface lithium abundance occurs when Li is destroyed at the base of the surface convection zone. For (current) F-, G-, and K-dwarfs, this is predicted to have occurred during the pre-Main-Sequence, only. In sharp contrast to the strictures of the SSET, real dwarfs continue to deplete their surface Li during the MS, and create surprising and extra-ordinary Li-Teff (or Li-mass) patterns such as the F-dwarf Li dip. Considerable and varied evidence points to rotationally-induced mixing as the dominant mechanism causing this extra Li depletion. New insights about the relation between stellar spindown and Li depletion in F-dwarfs are presented. Evidence from open clusters is presented that for higher mass dwarfs, spindown is likewise correlated with Li depletion, creating a second Li dip, but at higher mass and on a longer time scale.