The metal-poor end of the Spite plateau:gravity sensitivity of the Ha wings fitting.

摘要

We recently presented (Sbordone et al., 2009a) the largest sample to date of lithium abundances in extremely metal-poor (EMP) Halo dwarf and Turn-Off (TO) stars. One of the most crucial aspects in estimating Li abundances is the T_(eff) determination, since the Li I 670.8 nni doublet is highly temperature sensitive. In this short contribution we concentrate on the T_(eff) determination based on Ha wings fitting, and on its sensitivity to the chosen stellar gravity.