Element abundances of unevolved stars in the open cluster M 67

Context.The star-to-star scatter in lithium abundances observed among otherwise similar stars in the solar-age open cluster M 67 is one of the most puzzling results in the context of the so called “lithium problem”. Among other explanations, the hypothesis has been proposed that the dispersion in Li is due to star-to-star differences in Fe or other element abundances which are predicted to affect Li depletion.