2024ApJ...966..109S


Query : 2024ApJ...966..109S

2024ApJ...966..109S - Astrophys. J., 966, 109 (2024/May-1)

Mining the GALAH Data. I. Study of Five Super Lithium-rich Metal-poor Giants.

SUSMITHA A., MALLICK A. and REDDY B.E.

Abstract (from CDS):

The presence of a large amount of Li in giants is still a mystery. Most of the super Li-rich (SLR) giants reported in recent studies are in the solar metallicity regime. Here, we study the five metal-poor SLRs from the Galactic Archeology with HERMES Data Release 3, with their [Fe/H] ranging from -1.35 to -2.38 with lithium abundance of A(Li) ≥ 3.4 dex. The asteroseismic analysis reveals that none are on the red giant branch. The average period spacing (ΔP ) values indicate giants are in the core He-burning phase. All of them are low-mass giants (M < 1.5 M⊙). Their location in the Hertzsprung-Russell diagram suggests one of them is in the red clump (RC) phase, and interestingly, the other four are much brighter and coincide with the early asymptotic giant branch phase. The analysis of the abundance reveals that C, O, Na, Ba, and Eu are normal in giants of respective metallicities and evolutionary phases. Further, we did not find any strong evidence of the presence of dust in the form of infrared excess or binarity from the available radial velocity data. We discuss a few scenarios for the existence of SLRs at higher luminosity, including past merger events. Our findings will help in understanding the production and evolution of Li among giants, in particular, during the RC phase and the post-RC phase.

Abstract Copyright: © 2024. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Chemically peculiar stars - Giant stars - Lithium stars

Simbad objects: 5

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Number of rows : 5
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 UCAC4 253-045343 RG* 10 25 28.8405923344 -39 26 01.092107545   13.916 12.566 12.184   ~ 5 0
2 TYC 7262-250-1 RG* 13 09 32.2551227640 -37 09 17.787029148   13.38 11.47     ~ 5 0
3 UCAC4 308-077592 RG* 14 31 09.6555060438 -28 29 45.420336118   14.936 13.325 12.896   ~ 4 0
4 UCAC4 212-183136 RG* 20 29 16.1339162049 -47 41 51.506281373   15.014 13.785 13.600   ~ 5 0
5 UCAC4 099-098976 HB* 23 07 10.0983794710 -70 18 55.619191987   13.487 12.780 12.671   ~ 4 0

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