Lithium Inventory of 2 M_sun Red Clump Stars: Is Li Created During the He Flash?

TL;DR

This study investigates whether lithium is produced during the He flash in 2 solar mass red clump stars by measuring Li abundances in cluster stars before and after the red clump phase.

Contribution

It provides observational data on Li abundances in red clump stars to test the hypothesis of Li creation during the He flash.

Findings

Preliminary Li abundance measurements in red clump stars.

Comparison with baseline Li levels in upper red giant branch stars.

Implications for Li production during stellar evolution stages.

Abstract

A recent study of Li abundances in field red giant stars suggested that the phenomenon of enriched surface Li may be a short-lived phase of red clump evolution for stars with masses near 2 M_sun. Although the exact mechanism for generating this Li is not fully understood, it may be related to the He-core flash that immediately precedes the red clump stage. To test the incidence and timescale of this proposed process, we are targeting red clump stars in four southern open clusters, using the cluster ages to ensure that the stellar masses are ~2 M_sun. Additionally, we observe at least one upper red giant branch star in each cluster to establish the baseline Li abundance prior to the He flash. Here, we present preliminary results on the relative abundances of Li in the clusters' red clump stars.