Theoretical Examination of the Lithium Depletion Boundary

We explore the sensitivity in open cluster ages obtained by the lithiumdepletion boundary (LDB) technique to the stellar model input physics. The LDBage technique is limited to open clusters with ages ranging from 20 to 200 Myr.Effective 1-sig errors in the LDB technique due to uncertain input physics areroughly 3% at the oldest age increasing to 8% at the youngest age. Bolometriccorrection uncertainties add an additional 10 to 6% error to the LDB agetechnique for old and young clusters, respectively. Rotation rates matching theobserved fastest rotators in the Pleiades affect LDB ages by less than 2%. Therange of rotation rates in an open cluster are expected to ``smear'' the LDBlocation by only 0.02 mag for a Pleiades age cluster increasing to 0.06 mag fora 20 Myr cluster. Thus, the observational error of locating the LDB (~7-10%)and the bolometric correction uncertainty currently dominate the error in LDBages. For our base case, we formally derive a LDB age of 148 +- 19 Myr for thePleiades, where the error includes 8, 3, and 9% contributions fromobservational, theoretical, and bolometric correction sources, respectively. Amaximally plausible 0.3 magnitude shift in the I-band bolometric correction toreconcile main sequence isochrone fits with the observed (V-I) color for thelow mass Pleiades members results in an age of 126 +- 11 Myr, where the errorincludes observational and theoretical errors only. Upper main-sequence-fittingages that do not include convective core overshoot for the Pleiades (~75 Myr)are ruled out by the LDB age technique.Comment: 35 pages, 9 figures, accepted Ap