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Related papers: Halo Star Lithium Depletion

200 papers

The standard model of primordial nucleosynthesis by the Big Bang as selected by the WMAP-based estimate of the baryon density ($\Omega_bh^2$) predicts an abundance of $^7$Li that is a factor of three greater than the generally reported…

Astrophysics · Physics 2009-11-10 David L. Lambert

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

Based on 3D hydrodynamical model atmospheres computed with the CO5BOLD code and 3D non-LTE (NLTE) line formation calculations, we study the effect of the convection-induced line asymmetry on the derived 6Li abundance for a range in…

Solar and Stellar Astrophysics · Physics 2015-05-18 M. Steffen , R. Cayrel , P. Bonifacio , H. -G. Ludwig , E. Caffau

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

Lithium abundances in a sample of halo dwarfs have been redetermined by using the new T$_{eff}$ derived by Fuhrmann et al (1994) from modelling of the Balmer lines. These T$_{eff}$ are reddening independent, homogeneous and of higher…

Astrophysics · Physics 2007-05-23 P. Molaro , F. Primas , P. Bonifacio

The $^6$Li abundance observed in metal poor halo stars exhibits a plateau similar to that for $^7$Li suggesting a primordial origin. However, the observed abundance of $^6$Li is a factor of $10^3$ larger and that of $^7$Li is a factor of 3…

The existence of one percent of lithium-rich giant stars among normal, lithium-poor giant stars continues to be poorly explained. By merging two catalogues, one containing 10,535 lithium-rich giant stars with lithium abundances ranging from…

Solar and Stellar Astrophysics · Physics 2024-12-09 R. de la Reza

The chemical evolution of lithium in the Milky Way represents a major problem in modern astrophysics. Indeed, lithium is, on the one hand, easily destroyed in stellar interiors, and, on the other hand, produced at some specific stellar…

Astrophysics of Galaxies · Physics 2016-10-26 G. Guiglion , P. de Laverny , A. Recio-Blanco , C. C. Worley , M. De Pascale , T. Masseron , N. Prantzos , S. Mikolaitis

There is evidence in the 125-Myr Pleiades cluster, and more recently in the 5-Myr NGC 2264 cluster, that rotation plays a key role in the Lithium (Li) depletion processes among low-mass stars. Fast rotators appear to be less Li-depleted…

Solar and Stellar Astrophysics · Physics 2016-11-30 S. Messina , A. C. Lanzafame , G. A. Feiden , M. Millward , S. Desidera , A. Buccino , I. Curtis , E. Jofre' , P. Kehusmaa , B. J. Medhi , B. Monard , R. Petrucci

Aims. This study aims to determine the level and constancy of the Spite plateau as definitively as possible from homogeneous high-quality VLT-UVES spectra of 19 of the most metal-poor dwarf stars known. Methods. Our high-resolution (R ~…

Standard stellar evolution model predicts a severe depletion of lithium (Li) abundance during the first dredge-up process (FDU). Yet a small fraction of giant stars are still found to preserve a considerable amount of Li in their…

Known sources of lithium (Li) in the universe include the big bang, novae, asymptotic giant branch stars, and cosmic ray spallation. During their longer-lived evolutionary phases, stars are not expected to add to the Li budget of the…

Solar and Stellar Astrophysics · Physics 2022-07-20 Julio Chanamé , Marc H. Pinsonneault , Claudia Aguilera-Gómez , Joel C. Zinn

We adopt up-to-date 7Li yields from asymptotic giant branch stars in order to study the temporal evolution of 7Li in the solar neighbourhood in the context of a revised version of the two-infall model for the chemical evolution of our…

Astrophysics · Physics 2016-08-30 Donatella Romano , Francesca Matteucci , Paolo Ventura , Francesca D'Antona

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

The presence of 6Li in the atmospheres of metal-poor halo stars is usually inferred from the detection of a subtle extra depression in the red wing of the 7Li doublet line at 670.8 nm. However, the intrinsic line asymmetry caused by…

Solar and Stellar Astrophysics · Physics 2012-06-12 M. Steffen , R. Cayrel , E. Caffau , P. Bonifacio , H. -G. Ludwig , M. Spite

The discordance between `low' and `high' primordial D/H measurements can be considerably reduced if the analysis of the H+D profiles accounts for the correlated velocity field of bulk motion. We have re-estimated the value of D/H at z=3.572…

Astrophysics · Physics 2007-05-23 Sergei A. Levshakov

The parameter-free model of diffusion in the atmospheres of HgMn stars (Michaud 1986; Michaud et al 1979) predicts that helium should sink below the He II ionization zone in order that diffusion of other elements may take place, and that…

Astrophysics · Physics 2009-11-10 M. M. Dworetsky

Lithium is one of the few primordially produced elements. The value of the primordial Li is taken to be that observed in metal--poor dwarfs, where it is not contaminated by stellar Li sources which act on longer time scales. The atmospheric…

Astrophysics · Physics 2009-10-30 Piercarlo Bonifacio , Paolo Molaro

Stellar clusters are open windows to understand stellar evolution. Specifically, the change with time and the dependence on mass of different stellar properties. As such, they are our laboratories where different theories can be tested. We…

Solar and Stellar Astrophysics · Physics 2016-12-14 D. Barrado , H. Bouy , J. Bouvier , E. Moraux , L. M. Sarro , E. Bertin , J. C. Cuillandre , J. R. Stauffer , J. Lillo-Box , A. Pollock

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