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Related papers: Lithium in stars with exoplanets

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We test a scenario in which radial migration could affect the Li abundance pattern of dwarf stars in the solar neighbourhood. This may confirm that the Li abundance in these stars can not serve as a probe for the Li abundance in the…

Lithium is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. We present the results of a new large Lithium survey in red giant stars and combine it with surveys from the literature to…

Solar and Stellar Astrophysics · Physics 2020-01-08 C. Charbonnel , N. Lagarde , G. Jasniewicz , P. North , M. Shetrone , J. Krugler Hollek , V. V. Smith , R. Smiljanic , A. Palacios , G. Ottoni

While theoretical computations of the lithium abundances in Pop II stars predict variations from star to star, the most recent observations confirm the existence of a "lithium plateau" with no abundance dispersion. This apparent paradox has…

Astrophysics · Physics 2007-05-23 Sylvie Vauclair

About one percent of giants\upcite{Brown1989} are detected to have anomalously high lithium (Li) abundances in their atmospheres, conflicting directly with the prediction of the standard stellar evolution models\upcite{Iben1967}, and making…

Lithium abundances in a selected sample of halo stars have been revised by using the new accurate IRFM effective temperatures by Alonso, Arribas & Martinez-Roger (1996a). From 41 plateau stars (Teff > 5700 and [Fe/H] <= -1.5) we found no…

Astrophysics · Physics 2015-06-24 Piercarlo Bonifacio , Paolo Molaro

Extensive spectroscopic studies of stars with and without planets have concluded that stars hosting planets are significantly more metal-rich than those without planets. More subtle trends of different chemical elements begin to appear as…

Astrophysics · Physics 2007-05-23 Garik Israelian

This work presents a uniform and homogeneous study of chemical abundances of refractory elements in 101 stars with and 94 without known planetary companions. We carry out an in-depth investigation of the abundances of Si, Ca, Sc, Ti, V, Cr,…

Astrophysics · Physics 2009-11-11 G. Gilli , G. Israelian , A. Ecuvillon , N. C. Santos , M. Mayor

We present a line-by-line differential analysis of a sample of 16 planet hosting stars and 68 comparison stars using high resolution, high signal-to-noise ratio spectra gathered using Keck. We obtained accurate stellar parameters and…

Solar and Stellar Astrophysics · Physics 2020-05-22 F. Liu , D. Yong , M. Asplund , H. S. Wang , L. Spina , L. Acuna , J. Melendez , I. Ramirez

We present FLAMES/GIRAFFE spectroscopy obtained at the Very Large Telescope (VLT). Using these observations we have been able for the first time to observe the Li I doublet in the Main Sequence stars of a Globular Cluster. We also observed…

Astrophysics of Galaxies · Physics 2015-05-14 J. I. González Hernández , P. Bonifacio , E. Caffau , M. Steffen , H. -G. Ludwig , N. Behara , L. Sbordone , R. Cayrel , S. Zaggia

We present a study on the detailed elemental abundances of newly identified bright very metal-poor stars with the detection of lithium, initially observed as part of the SDSS/MARVELS pre-survey. These stars were selected for high-resolution…

Solar and Stellar Astrophysics · Physics 2022-10-05 Avrajit Bandyopadhyay , Thirupathi Sivarani , Timothy C. Beers , A. Susmitha , Prasanta K Nayak , Jeewan C Pandey

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

Precise Li abundances are determined for 54 giant stars mostly evolving across the Hertzsprung gap. We combine these data with rotational velocity and with information related to the deepening of the convective zone of the stars to analyse…

Astrophysics · Physics 2009-11-10 P. de Laverny , J. D. Jr do Nascimento , A. Lebre , J. R. De Medeiros

- Aims: We intended to quantify the impact of stellar multiplicity on the presence and properties of exoplanets. - Methods: We investigated all exoplanet host stars at less than 100 pc using the latest astrometric data from Gaia DR3 and…

Solar and Stellar Astrophysics · Physics 2024-09-25 J. González-Payo , J. A. Caballero , J. Gorgas , M. Cortés-Contreras , M. -C. Gálvez-Ortiz , C. Cifuentes

Our study is a follow-up of the SACY project, an extended survey in the Southern Hemisphere targeted to search for young nearby associations. Nine associations have either been newly identified, or had their member list better defined.…

Solar and Stellar Astrophysics · Physics 2015-05-14 L. da Silva , C. A. O. Torres , R. de la Reza , G. R. Quast , C. H. F. Melo , M. Sterzik

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

The relationship between the compositions of giant planets and their host stars is of fundamental interest in understanding planet formation. The solar system giant planets are enhanced above solar composition in metals, both in their…

Earth and Planetary Astrophysics · Physics 2019-12-11 Johanna K. Teske , Daniel Thorngren , Jonathan J. Fortney , Natalie Hinkel , John M. Brewer

Thanks to the high multiplex and efficiency of Giraffe at the VLT we have been able for the first time to observe the Li I doublet in the Main Sequence (MS) stars of a Globular Cluster. At the same time we observed Li in a sample of…

Astrophysics of Galaxies · Physics 2015-05-14 J. I. González Hernández , P. Bonifacio , E. Caffau , M. Steffen , H. -G. Ludwig , N. Behara , L. Sbordone , R. Cayrel , S. Zaggia

We present data for four ultra-Li-deficient, warm, halo stars. The Li deficiency of two of these is a new discovery. Three of the four stars have effective temperatures Teff ~ 6300 K, in contrast to previously known Li-deficient halo stars…

Astrophysics · Physics 2009-10-31 Sean G. Ryan , Timothy C. Beers , Toshitaka Kajino , Katarina Rosolankova

Helium abundances and atmospheric parameters have been determined from high resolution spectra for a new sample of 46 bright hot subdwarf B (sdB) stars. The helium abundances have been measured with high accuracy. We confirm the correlation…

Solar and Stellar Astrophysics · Physics 2011-12-14 S. Geier , U. Heber , H. Edelmann , L. Morales-Rueda , D. Kilkenny , D. O'Donoghue , T. R. Marsh , C. Copperwheat

It has recently been suggested that all giant stars with mass below 2 $M_{\odot}$ suffer an episode of surface lithium enrichment between the tip of the red giant branch (RGB) and the red clump (RC). We test if the above result can be…

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