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Related papers: First stars VII. Lithium in extremely metal poor d…

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Aims: The purpose of our study is to determine the chemical composition of a sample of 16 candidate Extremely Metal-Poor (EMP) dwarf stars, extracted from the Sloan Digital Sky Survey (SDSS). There are two main purposes: in the first place…

Astrophysics of Galaxies · Physics 2015-06-04 P. Bonifacio , L. Sbordone , E. Caffau , H. -G. Ludwig , M. Spite , J. I. González Hernández , N. T. Behara

We discuss the current status of the sample of Lithium abundances in extremely metal poor (EMP) turn-off (TO) stars collected by our group, and compare it with the available literature results. In the last years, evidences have accumulated…

Solar and Stellar Astrophysics · Physics 2012-07-02 L. Sbordone , P. Bonifacio , E. Caffau

Context. The study of old, metal-poor stars deepens our knowledge on the early stages of the universe. In particular, the study of these stars gives us a valuable insight into the masses of the first massive stars and their emission of…

Solar and Stellar Astrophysics · Physics 2021-10-04 A. Matas Pinto , M. Spite , E. Caffau , P. Bonifacio , L. Sbordone , T. Sivarani , M. Steffen , F. Spite , P. Francois , P. Di Matteo

This work presents a homogeneous determination of lithium abundances in a large sample of giant-planet hosting stars (N=117), and a control sample of disk stars without detected planets (N=145). The lithium abundances were derived using a…

Solar and Stellar Astrophysics · Physics 2010-11-04 L. Ghezzi , K. Cunha , V. V. Smith , R. de la Reza

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…

We have refined the estimate of the primordial level of $^7$Li abundance to an accuracy better than 10%, based on high-precision Li abundances for metal-poor halo stars, and a recent model of post-BBN (Big Bang Nucleosynthesis) chemical…

Astrophysics · Physics 2009-10-31 Takeru Ken Suzuki , Yuzuru Yoshii , Timothy C. Beers

We derive atmospheric parameters and lithium abundances for 671 stars and include our measurements in a literature compilation of 1381 dwarf and subgiant stars. First, a "lithium desert" in the effective temperature (Teff) versus lithium…

Solar and Stellar Astrophysics · Physics 2015-06-05 I. Ramirez , J. R. Fish , D. L. Lambert , C. Allende Prieto

We present a survey of lithium abundances in 185 main- sequence field stars with Teff between 5600 and 6600 K and [Fe/H] from -1.4 to +0.2 based on high-resolution spectra of 130 stars and a reanalysis of data from Lambert et al. (1991).…

Astrophysics · Physics 2009-11-06 Y. Q. Chen , P. E. Nissen , T. Benoni , G. Zhao

Since the pioneering observations of Spite & Spite in 1982, the constant lithium abundance of metal-poor ([Fe/H]<-1.3) halo stars near the turnoff has been attributed a cosmological origin. Closer analysis revealed that the observed…

Astrophysics · Physics 2008-11-26 L. Piau , T. C. Beers , D. S. Balsara , T. Sivarani , J. W. Truran , J. W. Ferguson

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

Lithium abundance derived in metal-poor main sequence stars is about three times lower than the value of primordial Li predicted by the standard Big Bang nucleosynthesis when the baryon density is taken from the CMB or the deuterium…

Solar and Stellar Astrophysics · Physics 2015-06-22 Xiaoting Fu , Alessandro Bressan , Paolo Molaro , Paola Marigo

We provide *lambda*6708 Li 1 measurements in 37 metal-poor stars, most of which are poorly-studied or have no previous measurements, from high-resolution and high-S/N spectroscopy obtained with the McDonald Observatory 2.1m and 2.7m…

Solar and Stellar Astrophysics · Physics 2015-06-03 Marc Schaeuble , Jeremy R. King

Two problems are discussed here. The first one is the 0.4 dex discrepancy between the 7Li abundance derived from the spectra of metal-poor halo stars on the one hand, and from Big Bang nucleosynthesis, based on the cosmological parameters…

We report results from lithium abundance determinations using high resolution spectral analysis of the 107 metal-rich stars from the Calan-Hertfordshire Extrasolar Planet Search programme. We set out to understand the lithium distribution…

Solar and Stellar Astrophysics · Physics 2018-03-21 Ya. V. Pavlenko , J. S. Jenkins , O. M. Ivanyuk , H. R. A. Jones , B. M. Kaminsky , Yu. P. Lyubchik , L. A. Yakovina

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

In 1982, Monique and Francois Spite discovered that the 7Li abundance in the atmosphere of old metal-poor dwarf stars in the galactic halo was independent of metallicity and temperature. Since then, 7Li abundance in the Universe has become…

High Energy Astrophysical Phenomena · Physics 2014-02-24 Rachid Ouyed

Very high-quality spectra of 24 metal-poor halo dwarfs and subgiants have been acquired with ESO's VLT/UVES for the purpose of determining Li isotopic abundances. The derived 1D, non-LTE 7Li abundances from the LiI 670.8nm line reveal a…

We present an elemental abundance analysis for four newly discovered ultra metal-poor stars from the Hamburg/ESO survey, with $\mathrm{[Fe/H]}\leq-4$. Based on high-resolution, high signal-to-noise spectra, we derive abundances for 17…

We investigate the history of $^6$Li and $^7$Li in population II dwarfs during the pre main sequence and main sequence. The evolution is followed using the CESAM code and taking into account the most recent physics. The effective…

Astrophysics · Physics 2007-05-23 Laurent Piau

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…