Kavli Affiliate: Anna Frebel
| First 5 Authors: Jeremy Kowkabany, Rana Ezzeddine, Corinne Charbonnel, Ian U. Roederer, Yangyang Li
| Summary:
We present the discovery of 2MASS J05241392-0336543 (hereafter J0524-0336), a
very metal-poor ([Fe/H]=-2.43 pm 0.16), highly r-process-enhanced
([Eu/Fe]=+1.34 pm 0.10) Milky Way halo field red giant star, with an ultra
high Li abundance of A(Li)(3D,NLTE)=5.62 pm 0.25 and [Li/Fe]=+7.00 pm 0.25,
respectively. This makes J0524-0336 the most lithium-enhanced giant star
discovered to date. We present a detailed analysis of the star’s atmospheric
stellar parameters and chemical-abundance determinations. Additionally, we
detect infrared excess and variable emission in the wings of the H$_alpha$
absorption line across multiple epochs, indicative of a potential enhanced
mass-loss event with possible outflows. Our analysis reveals that J0524-0336
lies either between the bump and the tip of the Red Giant Branch (RGB), or on
the early-Asymptotic Giant Branch (e-AGB). We investigate the possible sources
of lithium enrichment in J0524-0336, including both internal and external
sources. Based on current models and on the observational evidence we have
collected, our study shows that J0524-0336 may be undergoing the so-called
lithium flash that is expected to occur in low-mass stars when they reach the
RGB bump and/or the early-AGB.
| Search Query: ArXiv Query: search_query=au:”Anna Frebel”&id_list=&start=0&max_results=10