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Related papers: Lithium Depletion in Fully Convective Pre-Main Seq…

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The primordial elements, H, He and Li are included in a low temperature equation of state and monochromatic opacity function. The equation of state and opacity function are incorporated into the stellar evolution code NG-ELMS, which makes…

Astrophysics · Physics 2008-11-26 G. J. Harris , A. E. Lynas-Gray , S. Miller , J. Tennyson

The rapidly rotating cool dwarfs of the Pleiades are rich in lithium relative to their slowly rotating counterparts. Motivated by observations of inflated radii in young, active stars, and by calculations showing that radius inflation…

Solar and Stellar Astrophysics · Physics 2015-06-23 Garrett Somers , Marc H. Pinsonneault

The observations of light elements in the Sun and Solar type stars give special clues for understanding the hydrodynamical processes at work in stellar interiors. In the Sun 7Li is depleted by 140 while 3He has not increased by more than…

Astrophysics · Physics 2007-05-23 Sylvie Vauclair

Although the means of the ages of stars in young groups determined from Li depletion often agree with mean ages determined from Hertzsprung - Russell diagram isochrones, there are often statistically significant differences in the ages of…

Solar and Stellar Astrophysics · Physics 2015-05-19 J. Macdonald , D. J. Mullan

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

In Paper I, we classified a stellar sample from the thin disc with a broad range in metallicity as being churned outward or inward, or blurred/undisturbed. In this paper (Paper II), we delve deeper by analysing our entire…

Solar and Stellar Astrophysics · Physics 2025-07-11 M. L. L. Dantas , R. Smiljanic , D. Romano , G. Guiglion , L. Magrini , P. B. Tissera , R. S. de Souza

Stellar evolution models which include the effect of helium and heavy element diffusion have been calculated for initial iron abundances of [Fe/H] = -2.3, -2.1, -1.9 and -1.7. These models were calculated for a large variety of masses and…

Astrophysics · Physics 2011-02-11 Brian Chaboyer , W. H. Fenton , Jenica E. Nelan , D. J. Patnaude , Francesca E. Simon

Israelian et al. (2004) reported that exoplanet host stars are lithium depleted compared to solar-type stars without detected massive planets, a result recently confirmed by Gonzalez (2008). We investigate whether enhanced lithium depletion…

Astrophysics · Physics 2009-11-13 Jerome Bouvier

Transport processes occurring in the radiative interior of solar-type stars are evidenced by the surface variation of light elements, in particular Li, and the evolution of their rotation rates. For the Sun, inversions of helioseismic data…

Solar and Stellar Astrophysics · Physics 2021-02-10 T. Dumont , A. Palacios , C. Charbonnel , O. Richard , L. Amard , K. Augustson , S. Mathis

We present Li abundances for 73 stars in the metallicity range -3.5 < [Fe/H] < -1.0 using improved IRFM temperatures (Casagrande et al. 2010) with precise E(B-V) values obtained mostly from interstellar NaI D lines, and high-quality…

Solar and Stellar Astrophysics · Physics 2015-05-14 J. Melendez , L. Casagrande , I. Ramirez , M. Asplund , W. J. Schuster

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

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 present an empirical model of age-dependent photospheric lithium depletion, calibrated using a large, homogeneously-analysed sample of 6200 stars in 52 open clusters, with ages from 2--6000 Myr and $-0.3<{\rm [Fe/H}]<0.2$, observed in…

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…

For the purpose of deriving the helium abundances in chemically peculiar stars, the importance of assuming a correct helium abundance has been investigated for determining the effective temperature and gravity of main sequence B-type stars,…

Astrophysics · Physics 2007-05-23 F. Leone

This overview summarizes the age dating methods available for young sub-solar mass stars. Pre-main sequence age diagnostics include the Hertzsprung-Russell (HR) diagram, spectroscopic surface gravity indicators, and lithium depletion;…

Astrophysics · Physics 2015-05-13 Lynne A. Hillenbrand

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

The vast majority of stars with mass similar to the Sun are expected to only destroy lithium over the course of their lives, via low-temperature nuclear burning. This has now been supported by observations of hundreds of thousands of red…

Solar and Stellar Astrophysics · Physics 2020-07-15 Yerra Bharat Kumar , Bacham E. Reddy , Simon W. Campbell , Sunayana Maben , Gang Zhao , Yuan-Sen Ting

We have determined Li abundances for 11 G-type stars in the 6-8 Gyr old open cluster NGC 188. These data significantly enlarge the number of cluster stars with Li measurements, allowing us to extend the investigation of Li depletion in open…

Astrophysics · Physics 2008-11-26 Sofia Randich , Paola Sestito , Roberto Pallavicini

High resolution (R=110000), very high S/N spectra, centered on the 6707.8A LiI line have been obtained with the ESO Coude Echelle Spectrometer for five, metal-poor (-0.8 < [Fe/H] < -0.6) disk stars in the turnoff region of the HR-diagram.…

Astrophysics · Physics 2007-05-23 P. E. Nissen , D. L. Lambert , F. Primas , V. V. Smith