The Abundances of Li in δ Scuti Stars: Can They Explain the Li Dip?

Abstract

Several years ago it was suggested that mass loss from δ Scuti stars may transform them into the ‘lithium dip’ stars seen in older galactic clusters. Although several strands of evidence indicate that this is unlikely, there has never been a study made of the lithium abundances in delta Scuti stars themselves. This paper reports the preliminary results from a survey of lithium in these stars.

Lithium was detected in about half of the stars studied, with only upper limits being determined for the others. For those stars with measurable lithium there is evidence for a moderate depletion at the cooler temperatures, but not enough to explain the lithium dip. For those stars with no measurable lithium, the upper limits are consistent with only moderate depletion in all except one or two cases.