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Related papers: Lithium Depletion in Pre-Mainsequence Solar-Like S…

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The observed amount of lithium for low metallicity population II stars (known as the Spite plateau) is a factor of $\sim 3-5$ lower than the predictions of the standard cosmology. Since the observations are limited to the local Universe…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-06 Maxim Pospelov , Niayesh Afshordi

Mixing mechanisms bring the Li from the base of the convective zone to deeper and warmer layers where it is destroyed. These mechanisms are investigated by comparing observations of Li abundances in stellar atmospheres to models of stellar…

Solar and Stellar Astrophysics · Physics 2015-06-17 Matthieu Castro , Giancarlo Pace , José Dias do Nascimento

We exploit the unique characteristics of a sample of open clusters (OCs) and field stars for which high-precision 7Li abundances and stellar parameters are homogeneously derived by the Gaia-ESO Survey (GES). We derive possibly undepleted…

Stellar models with masses ranging from 0.5 to $1.3~M_\odot$ were constructed in order to compare to young cluster observations of Li and of rotation velocities. The amount of Li depletion in cool stars is sensitive to the amount of…

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

We present spectroscopic observations of candidate F, G and K type stars in NGC 6633, an open cluster with a similar age to the Hyades. We identify 10 new cluster members including one short period binary system. Combining this survey with…

Astrophysics · Physics 2009-11-07 R. D. Jeffries , E. J. Totten , S. Harmer , C. P. Deliyannis

We investigate the distribution of the lithium abundances, A(Li), of metal-poor dwarf and subgiant stars within the limits 5500 K < Teff < 6700 K, -6.0 < [Fe/H] < -1.5, and logg > ~3.5 (a superset of parameters first adopted by Spite and…

Solar and Stellar Astrophysics · Physics 2023-04-05 J. E. Norris , D. Yong , A. Frebel , S. G. Ryan

We report novel observational evidence on the evolutionary status of lithium-rich giant stars by combining asteroseismic and lithium abundance data. Comparing observations and models of the asteroseismic gravity-mode period spacing…

Solar and Stellar Astrophysics · Physics 2021-05-26 Raghubar Singh , Bacham E. Reddy , Simon W. Campbell , Yerra Bharat Kumar , Mathieu Vrard

Lithium abundance in most of the warm metal-poor main sequence stars shows a constant plateau (A(Li)~2.2 dex) and then the upper envelope of the lithium vs. metallicity distribution increases as we approach solar metallicity. Meteorites,…

Mapping lithium evolution for evolved stars will provide restrictions and constraints on the fundamental stellar interior physical processes, which further shed light on our understanding of the theory of stellar structure and evolution.…

Solar and Stellar Astrophysics · Physics 2021-09-29 Jinghua Zhang , Jian-Rong Shi , Hong-Liang Yan , Yaguang Li , Qi Gao , Chun-Qian Li , Xianfei Zhang , Shuai Liu , Shaolan Bi , Gang Zhao , Yan Li

High-resolution CTIO 4-m/HYDRA spectroscopy of the super-metal-rich open cluster NGC 6253 ([Fe/H]=+0.43+/-0.01) has been used to study the stellar lithium (Li) abundances near the cluster's turnoff. NGC 6253 greatly expands the range of…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jeffrey D. Cummings , Constantine P. Deliyannis , Barbara Anthony-Twarog , Bruce Twarog , Ryan M. Maderak

Pre-main sequence models with inflated radii are needed to simultaneously reproduce the colour-magnitude diagram and the lithium depletion pattern in young open clusters. We tested a new set of PMS models including radius inflation due to…

Studies of beryllium abundance in large samples of solar-type stars show a small fraction of extremely beryllium-deficient stars, which challenges our current understanding of light element depletion in these stars. We suggest two possible…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. Viallet , I. Baraffe

We have performed a new and homogeneous analysis of all the Li data available in the literature for main sequence stars (spectral-types from late F to K) in open clusters. In the present paper we focus on a detailed investigation of MS Li…

Astrophysics · Physics 2009-11-11 P. Sestito , S. Randich

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

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

Aims: We study the influence of rotation and disc lifetime on lithium depletion of pre-main sequence (PMS) solar-type stars. Methods: The impact of rotational mixing and of the hydrostatic effects of rotation on lithium abundances are…

Solar and Stellar Astrophysics · Physics 2015-06-05 P. Eggenberger , L. Haemmerlé , G. Meynet , A. Maeder

Previous studies of open clusters have shown that lithium depletion is not only strongly age dependent but also shows a complex pattern with other parameters that is not yet understood. For pre- and main-sequence late-type stars, these…

We present lithium abundances for 119 main-sequence stars in the old open cluster NGC 188 (age = 6.3 Gyr), using high-resolution, high signal-to-noise ratio spectra from WIYN/Hydra. We observe the stars over multiple nights and measure…

Solar and Stellar Astrophysics · Physics 2025-09-19 Qinghui Sun , Constantine P. Deliyannis , Bruce A. Twarog , Barbara J. Anthony-Twarog

We report the discovery of a peculiar set of old super-metal-rich dwarf stars with orbits of low eccentricity that reach a maximum height from the Galactic plane between $\sim$ 0.5-1.5 kpc observed by the \emph{Gaia}-ESO Survey. These stars…

Solar and Stellar Astrophysics · Physics 2025-01-29 M. L. L. Dantas , R. Smiljanic , R. Boesso , H. Rocha-Pinto , L. Magrini , G. Guiglion , D. Romano
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