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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

The surface content of lithium (Li) and beryllium (Be) provide insights into the mixing and circulation mechanisms in stellar interiors. The old open cluster, M 67, has been well-studied for Li abundances in both main-sequence and evolved…

Solar and Stellar Astrophysics · Physics 2019-10-18 Ann Merchant Boesgaard , Michael G. Lum , Constantine P. Deliyannis

I shall review what has been learnt during 20 years of lithium observations in stars belonging to metal-poor globular clusters. The focus will be on little evolved main-sequence, turnoff-point (TOP) and subgiant-branch (SGB) stars expected…

Solar and Stellar Astrophysics · Physics 2012-06-28 A. J. Korn

Lithium abundance A(Li) and surface rotation are good diagnostic tools to probe the internal mixing and angular momentum transfer in stars. We explore the relation between surface rotation, A(Li) and age in a sample of seismic…

We present lithium abundances for ~50 X-ray selected candidate members of the 30-50 Myr old open clusters IC 2602 and IC 2391. These data enlarge and extend to cooler temperatures previous Li surveys of these clusters by Stauffer et al.…

Astrophysics · Physics 2009-11-06 S. Randich , R. Pallavicini , G. Meola , J. R. Stauffer , Suchitra C. Balachandran

We present the results of a spectroscopic survey of X-ray selected, low-mass candidate members of the young open cluster NGC 2547. Using a combination of photometry, spectroscopic indices and radial velocities we refine our candidate list…

Astrophysics · Physics 2009-11-07 R. D Jeffries , J. M. Oliveira , D. Barrado y Navascues , J. R. Stauffer

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 surface abundance of lithium on the Sun is 140 times less than protosolar, yet the temperature at the base of the surface convective zone is not hot enough to burn Li. A large range of Li abundances in solar type stars of the same age,…

A discrepancy has emerged between the cosmic lithium abundance inferred by the WMAP satellite measurement coupled with the prediction of the standard big-bang nucleosynthesis theory, and the constant Li abundance measured in metal-poor halo…

Astrophysics of Galaxies · Physics 2015-05-19 L. Monaco , P. Bonifacio , L. Sbordone , S. Villanova , E. Pancino

A new scenario --early disc accretion-- has been recently proposed to explain the discovery of multiple stellar populations in Galactic globular clusters. According to this model, the existence of well defined (anti)-correlations amongst…

Astrophysics of Galaxies · Physics 2014-07-02 M. Salaris , S. Cassisi

One of the most important factors in determining the stellar lithium abundance is the effective temperature. In a previous study by the authors, new effective temperatures Teff for sixteen metal-poor halo dwarfs were derived using a local…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Hosford , A. E. Garcia Perez , R. Collet , S. G. Ryan , J. E. Norris , K. A. Olive

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…

Lithium abundances are presented for 91 dwarf and subgiant stars in the Galactic bulge. The analysis is based on line synthesis of the 7Li line at 6707 {\AA} in high-resolution spectra obtained during gravitational microlensing events, when…

Astrophysics of Galaxies · Physics 2020-02-26 T. Bensby , S. Feltzing , J. C. Yee , J. A. Johnson , A. Gould , M. Asplund , J. Meléndez , S. Lucatello

Aims: The effects of rotation and magnetic fields on the surface abundances of solar-type stars are studied in order to investigate whether the reported difference in lithium content of exoplanet-host stars can be related to their…

Solar and Stellar Astrophysics · Physics 2015-05-20 P. Eggenberger , A. Maeder , G. Meynet

The dependence of lithium abundance on modified gravity in low-mass stellar objects is demonstrated. This may introduce an additional uncertainty to age determination techniques of young stars and globular clusters if they rely on the light…

General Relativity and Quantum Cosmology · Physics 2021-02-24 Aneta Wojnar

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

We study the temporal evolution of the 7Li abundance in the gaseous medium for all the components (halo, disk and bulge) of our Galaxy. We adopt nucleosynthesis prescriptions on stellar lithium production based upon recent observational…

Astrophysics · Physics 2016-08-30 Donatella Romano

Lithium (Li) abundance is an age indicator for G, K, and M stellar types, as its abundance decreases over time for these spectral types. However, despite the observational efforts made over the past few decades, the role of rotation,…

Solar and Stellar Astrophysics · Physics 2024-05-15 D. Cuenda-Muñoz , D. Barrado , M. A. Agüeros , J. L. Curtis , H. Bouy

We determine lithium (Li) abundances for solar twins in the M67 open cluster to add valuable information about the correlation between Li depletion and stellar age and, then, better understand stellar structure and evolution. We use high…

Solar and Stellar Astrophysics · Physics 2020-01-08 Marilia Carlos , Jorge Melendez , Jose-Dias do Nascimento , Matthieu Castro

We derive lithium abundances in 53 T Tauri stars (TTS), concentrating on weak-line TTS. Our study gives the following results: 1)At luminosities $\ge 0.9 L\sun$ the Li abundances are remarkably uniform, with a mean value, log~N(Li)=3.1,…

Astrophysics · Physics 2019-08-17 E. L. Martin , R. Rebolo , A. Magazzu , Ya. V. Pavlenko