Lithium and binarity in M67

Abstract

A study of the lithium abundances in binaries of the old open cluster M67 is presented. Abundances were estimated using curves of growth and equivalent widths of the LiI6707.8 Å doublet. We have corrected of the effects of the companion on the measured equivalent width and on the color indices by deconvolving the photometry, computing colors and magnitudes for each component. As happens in the Hyades cluster, there are some lithium excesses in main-sequence and evolved TLBS binaries with respect other binaries and single stars, although the M67 data have large errors.