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We investigate the properties of 1262 red giant stars with high photospheric abundances of lithium observed by the GALAH and \Ktwo-HERMES surveys, and discuss them in the context of proposed mechanisms for lithium enrichment and…

Lithium abundances and rotation, determined for 120 subgiant stars in Lebre et al. (1999) are analyzed. To this purpose, the evolutionary status of the sample as well as the individual masses have been determined using the HIPPARCOS…

Astrophysics · Physics 2007-05-23 J. D. do Nascimento , C. Charbonnel , A. Lebre , P. de Laverny , J. R. De Medeiros

We present a study of correlations between high Li abundances and strong chromospheric He I 10830 \AA\ absorption line strengths in Kepler field giant stars. Our sample includes 84 giants with detectable solar-like oscillations in their…

Solar and Stellar Astrophysics · Physics 2025-01-16 Anohita Mallick , Christopher Sneden , Bacham E. Reddy , Melike Afşar

Reconstructing the Galactic evolution of lithium (Li) is the main tool used to constrain the source(s) of Li enrichment in the Galaxy. Recent results have suggested a decline in Li at supersolar metallicities, which may indicate reduced…

A large number of stellar evolution models with [Fe/H] = -2.3 and -3.3 have been calculated in order to determine the primordial $^7$Li abundance and to test current stellar evolution models by a comparison to the extensive database of Li…

Astrophysics · Physics 2009-10-22 Brian Chaboyer , P. Demarque

High-resolution optical spectra of sixteen red giants, two early asymptotic giant branch (AGB) stars, and two supergiants, having no/minimal to super lithium (Li)-rich abundances, are analyzed to investigate the helium (He)-enhancement. The…

Solar and Stellar Astrophysics · Physics 2025-07-02 B. P. Hema , Gajendra Pandey

The observed lithum (Li) abundance of Galactic halo stars mainly fall within the range of 2.0--2.4 dex. This nearly constant value, known as the Spite plateau, is approximately a factor of three lower than the value predicted from cosmic…

Solar and Stellar Astrophysics · Physics 2026-02-27 Wuming Yang , Shuya Dou , Xiangcun Meng , Yaqian Wu , Shaolan Bi

Although not predicted by standard stellar evolution, the surface abundance of light elements, such as lithium (Li), carbon, and nitrogen, changes during the red giant branch (RGB) as a result of extra-mixing. This is associated usually…

Solar and Stellar Astrophysics · Physics 2023-02-08 Claudia Aguilera-Gómez , Matías I. Jones , Julio Chanamé

The study of Li phenomena in red clump (RC) stars can give us a deeper understanding of the structure and evolution of stars. \citet{2022ApJ...933...58C} explained the RC Li abundance distributions naturally using only standard post main…

Solar and Stellar Astrophysics · Physics 2024-03-05 Xuefeng Li , Jianrong Shi , Yan Li , Hongliang Yan , Jinghua Zhang

A small fraction of low-mass stars have been found to have anomalously high Li abundances. Although it has been suggested that mixing during the red giant branch phase can lead to Li production, this method of intrinsic Li production cannot…

A highly homogeneous study of 23 halo field dwarf stars has achieved a Li abundance accuracy of 0.033 dex per star. The work shows that the intrinsic spread of the Li abundances of these stars at a given metallicity is <0.02 dex, and…

Astrophysics · Physics 2007-05-23 Sean G. Ryan

A subset of low-mass giants ($<2.2\,M_{\odot}$) exhibit anomalous lithium enhancement behavior, which is still an open topic. Given that more massive giants retain more surface lithium, increasing mass by accreting circumstellar matter…

Solar and Stellar Astrophysics · Physics 2025-08-04 Xuefeng Li , Jianrong Shi , Yan Li , Hongliang Yan , Jinghua Zhang , Fei Guo

Aims: We report the discovery of a young lithium rich giant, HD 16771, in the core-helium burning phase that does not seem to fit existing proposals of Li synthesis near the luminosity function bump or during He-core flash. We aim to…

Solar and Stellar Astrophysics · Physics 2016-04-13 Arumalla B. S. Reddy , David L. Lambert

Observations demonstrate that the surface abundance of $^7{\rm Li}$ in low-mass stars changes dramatically between the tip of the red giant branch and the red clump. This naturally suggests an association with the helium core flash, which…

Solar and Stellar Astrophysics · Physics 2020-09-30 Josiah Schwab

Despite the large number of studies focused on the characterisation of Li-rich stars and understanding the mechanisms leading to such enrichment, their origin remains a mystery. Magnetic activity, particularly the phenomena usually…

Solar and Stellar Astrophysics · Physics 2024-08-13 Inês Rolo , Elisa Delgado Mena , Maria Tsantaki , João Gomes da Silva

Lithium depletion and enrichment in the cosmos is not yet well understood. To help tighten constraints on stellar and Galactic evolution models, we present the largest high-resolution analysis of Li abundances A(Li) to date, with results…

The lithium abundance, A(Li), in stellar atmospheres suffers from various enhancement and depletion processes during the star's lifetime. While several studies have demonstrated that these processes are linked to the physics of stellar…

We present Li and Fe abundances for 87 stars in the GC M4,obtained with GIRAFFE high-resolution spectra. The targets range from the TO up to the RGB Bump. The Li abundance in the TO stars is uniform, with an average value A(Li)=2.30+-0.02…

Solar and Stellar Astrophysics · Physics 2015-05-20 A. Mucciarelli , M. Salaris , L. Lovisi , F. R. Ferraro , L. Lanzoni , S. Lucatello , R. G. Gratton

Most metal-rich AGB/RGB stars present strong Li underabundances, since this element is easily destroyed in the high temperatures of the stellar interiors. In spite of this fact, several of these stars are Li-rich, having Li abundances given…

Solar and Stellar Astrophysics · Physics 2016-12-07 W. J. Maciel , R. D. D. Costa

The prediction of the PLANCK-constrained primordial lithium abundance in the Universe is in discordance with the observed Li abundances in warm Population II dwarf and subgiant stars. Among the physically best motivated ideas, it has been…

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