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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…

Stellar models predict that lithium (Li) inside a star is destroyed during the first dredge-up phase, yet 1.2% of red giant stars are Li-rich. We aim to uncover possible origins of this population, by analysing 1155 Li-rich giants (A(Li)…

Metal-poor stars are crucially important for understanding the early Galaxy, first stars, and the Universe. In this series of papers, we present a homogeneous non-local thermodynamic equilibrium (NLTE) abundances analysis of 12 elements for…

[ABRIDGED] We determine Li abundances for a well-studied sample of 714 F and G dwarf, turn-off, and subgiant stars in the solar neighbourhood. The analysis is based on line synthesis of the Li line at 6707 {\AA} in high-resolution and high…

Astrophysics of Galaxies · Physics 2018-08-01 Thomas Bensby , Karin Lind

A search for lithium is performed on seven metal poor dwarfs with metallicities ranging from [Fe/H]=-1.5 down to [Fe/H]=-3.0 but showing disk-like kinematics. These stars belong to the metal poor tail of the Galactic thick disk and they may…

Astrophysics · Physics 2016-01-13 P. Molaro , P. Bonifacio , L. Pasquini

Context. About 0.2-2% of giant stars are Li-rich, whose lithium abundance (A(Li)) is higher than 1.5 dex. Among them, near 6% are super Li-rich with A(Li) exceeding 3.2 dex. Meanwhile, the formation mechanism of these Li-rich and super…

Solar and Stellar Astrophysics · Physics 2022-12-14 Jun Gao , Chunhua Zhu , Jinlong Yu , Helei Liu , Xizhen Lu , Jianrong Shi , Guoliang Lü

In this article, we speculate on the possible mechanisms for Li enhancement origin in RGB stars based on a large data set of around 340,299 stars collected from the GALAH survey combined with the Gaia astrometry. Data has 51,982 low mass…

Solar and Stellar Astrophysics · Physics 2019-01-29 Deepak , Bacham Eswar Reddy

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

We present a comparison of the lithium abundances of stars with and without planetary-mass companions. New lithium abundances are reported in 79 planet hosts and 38 stars from a comparison sample. When the Li abundances of planet host stars…

Astrophysics · Physics 2009-11-10 Garik Israelian , Nuno Santos , Michel Mayor , Rafael Rebolo

Preliminary abundances of lithium and a few other elements have been obtained for 31 field Am stars with good Hipparcos parallaxes, as well as for 36 normal A and F stars. Radial and projected rotational velocities were determined as well.…

Astrophysics · Physics 2009-11-11 P. North , F. Betrix , C. Besson

Context: A small number of K-type giants on the red giant branch (RGB) is known to be very rich in lithium (Li). This fact is not accounted for by standard stellar evolution theory. The exact phase and mechanism of Li enrichment is still a…

Solar and Stellar Astrophysics · Physics 2015-06-03 Thomas Lebzelter , Stefan Uttenthaler , Maurizio Busso , Mathias Schultheis , Bernhard Aringer

Aims. We present a spectroscopic analysis of a sample of evolved stars in M67 (turn-off, subgiant and giant stars) in order to bring observational constraints to evolutionary models taking into account non-standard transport processes.…

Solar and Stellar Astrophysics · Physics 2015-03-17 B. L. Canto Martins , A. Lèbre , A. Palacios , P. de Laverny , O. Richard , C. H. F. Melo , J. D. do Nascimento , J. R. De Medeiros

The temperature distribution of field Li-rich red giants suggests the presence of a population of Li-rich red clump (RC) stars. One proposed explanation for this population is that all stars with masses near 2 $M_\odot$ experience a…

Solar and Stellar Astrophysics · Physics 2016-08-24 Joleen K. Carlberg , Katia Cunha , Verne V. Smith

We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li…

Astrophysics of Galaxies · Physics 2015-06-05 P. E. Nissen , W. J. Schuster

Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai…

The orders of magnitude variation in lithium abundances of evolved stars have long been a puzzle. Diluted signals, ambiguous evolutionary states and unknown masses have made it challenging to both map the expected lithium signals and…

Solar and Stellar Astrophysics · Physics 2023-07-26 Jamie Tayar , Joleen K. Carlberg , Claudia Aguilera-Gómez , Maryum Sayeed

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 and zirconium abundances (the latter taken as representative for s-process enrichment) are determined for a large sample of massive Galactic O-rich AGB stars, for which high resolution optical spectroscopy has been obtained…

Astrophysics · Physics 2009-11-11 D. A. Garcia-Hernandez , P. Garcia-Lario , B. Plez , A. Manchado , F. D'Antona , J. Lub , H. Habing

We present a critical analysis of the nature of the so-called Li-rich RGB stars. For a majority of the stars, we have used Hipparcos parallaxes to determine masses and evolutionary states by comparing their position on the…

Astrophysics · Physics 2007-05-23 Corinne Charbonnel , Suchitra C. Balachandran

We present a search for post-main-sequence field stars in the Galaxy with atypically large lithium abundances. Using moderate-resolution spectra taken as part of the Sloan Digital Sky Survey, along with high-resolution followup spectroscopy…

Solar and Stellar Astrophysics · Physics 2015-06-12 Sarah L. Martell , Matthew D. Shetrone