Lithium Abundances in the alpha Per Cluster

TL;DR

This study measures lithium abundances in 70 stars of the 50-million-year-old alpha Per cluster, revealing patterns related to stellar temperature, rotation, and comparison with other clusters.

Contribution

It provides new high-resolution spectra data and analyzes lithium abundance trends and scatter in alpha Per, comparing with younger clusters like the Pleiades.

Findings

Li abundance in F-type stars matches initial levels, indicating little pre-main sequence depletion.

Star-to-star Li abundance scatter is comparable to measurement errors.

Li abundance declines sharply below 5500 K, with scatter similar to that in the Pleiades.

Abstract

Lithium abundances are presented and discussed for 70 members of the 50 Myr old open cluster alpha Per. More than half of the abundances are from new high-resolution spectra. The Li abundance in the F-type stars is equal to its presumed initial abundance confirming previous suggestions that pre-main sequence depletion is ineffective for these stars. Intrinsic star-to-star scatter in Li abundance among these stars is comparable to the measurement uncertainties. There is marginal evidence that the stars of high projected rotational velocity v sini follow a different abundance vs temperature trend to the slow rotators. For stars cooler than about 5500 K, the Li abundance declines steeply with decreasing temperature and there develops a star-to-star scatter in the Li abundance. This scatter is shown to resemble the well documented scatter seen in the 70 Myr old Pleiades cluster. The scatter appears to be far less pronounced in the 30 Myr clusters which have been studied for Li abundance.