Lithium-rich giants in the Sagittarius dSph Tidal Streams

TL;DR

This paper reports the discovery of two super lithium-rich giant stars in the Sagittarius dwarf galaxy's tidal streams, providing insights into lithium production in evolved stars within dwarf spheroidal galaxies.

Contribution

It presents the first identification of super Li-rich giants in the Sagittarius dSph, highlighting potential lithium production mechanisms in such environments.

Findings

Discovery of 2 super Li-rich giants in Sagittarius dSph

Li-rich giants are rare, previously known only in Draco and the Milky Way

Supports the idea of lithium production via extra-mixing processes in giants

Abstract

The nature and origin of Lithium rich giant stars is still matter of debate. In the contest of our spectroscopic survey of giants in the tidal streams of the Sagittarius dwarf spheroidal (dSph) galaxy, we present the serendipitous discovery of 2 super Li-rich stars (A(Li)$>$3.5-4.0). Besides D461 in Draco, these are the only Li-rich stars known in a Local Group dSph galaxy. The high Li abundance and the low mass of these stars support their origin as due to fresh Li production in the stars associated with some kind of extra-mixing process.