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Related papers: Lithium in the Coma Berenices open cluster

200 papers

Context: Knowledge of the age distribution of stars in young clusters and associations is crucial to constrain models of star formation. HR diagrams of different young clusters and associations suggest the presence of age spreads, but the…

Astrophysics · Physics 2009-11-11 G. G. Sacco , S. Randich , E. Franciosini , R. Pallavicini , F. Palla

The evolution of lithium abundance over a star's lifetime is indicative of transport processes operating in the stellar interior. We revisit the relationship between lithium content and rotation rate previously reported for cool dwarfs in…

Solar and Stellar Astrophysics · Physics 2018-06-13 J. Bouvier , D. Barrado , E. Moraux , J. Stauffer , L. Rebull , L. Hillenbrand , A. Bayo , I. Boisse , H. Bouy , E. DiFolco , J. Lillo-Box , M. Morales Calderon

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

We have used Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) radial velocity observations in the near-infrared $H$-band to explore the membership of the nearby ($86.7 \pm 0.9$ pc) open…

We have measured the Li abundance of 18 stars with -2 <~ [Fe/H] ~< -1 and 6000 K <~ Teff <~ 6400 K, a parameter range that was poorly represented in previous studies. We examine the Galactic chemical evolution (GCE) of this element,…

This work aims to investigate the behaviour of the lithium abundance in stars with and without detected planets. Our study is based on a sample of 1332 FGK main-sequence stars with measured lithium abundances, for 257 of which planets were…

Solar and Stellar Astrophysics · Physics 2024-02-05 F. Llorente de Andrés , R. de la Reza , P. Cruz , D. Cuenda-Muñoz , E. J. Alfaro , C. Chavero , C. Cifuentes

Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M > 0.8 Msun) that are now extinct. In particular, it is expected that the observed abundance of Li should deviate in these stars from…

Solar and Stellar Astrophysics · Physics 2012-06-01 T. Masseron , J. A. Johnson , S. Lucatello , A. Karakas , B. Plez , T. C. Beers , N. Christlieb

We have determined Be abundances in 50 F and G dwarfs in the mass range of 0.9 $\leq$ M$_\odot$ $\leq$ 1.1 as determined by Lambert & Reddy. The effective temperatures are 5600 to 6400 K and metallicities from $-$0.65 to +0.11. The spectra…

Astrophysics · Physics 2015-05-13 Ann Merchant Boesgaard , Julie A. Krugler

Observational constraints on the primordial lithium abundance are important for the evaluation of the baryonic density of the universe. Its precise determination however suffers from uncertainties due to the possible depletion of this…

Astrophysics · Physics 2009-10-30 Sylvie Vauclair , Corinne Charbonnel

We present a study of beryllium (Be) abundances in a large sample of field solar-type dwarfs and sub-giants spanning a large range of effective temperatures. The analysis shows that Be is severely depleted for F stars, as expected by the…

Astrophysics · Physics 2009-11-10 N. C. Santos , G. Israelian , S. Randich , R. J. Garcia Lopez , R. Rebolo

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

With an aim of clarifying the extent and parameter-dependence of compositional anomaly of barium in A-type stars, Ba abundances were spectroscopically determined based on BaII 6141/6496 lines for 89 (23 A-type and 66 F--G-type)…

Solar and Stellar Astrophysics · Physics 2025-10-24 Yoichi Takeda

We report the discovery of a kinematically cold group of stars, located in the immediate neighborhood of the well-known star cluster Coma Berenices (Mel 111). The new group identified in tangential velocity space as measured by Gaia…

Astrophysics of Galaxies · Physics 2019-04-17 Verena Fürnkranz , Stefan Meingast , João Alves

We have obtained low and medium resolution spectra of 9 brown dwarf candidate members of Coma Berenices and the Hyades using SpEX on the NASA InfaRed Telescope Facility and LIRIS on the William Herschel Telescope. We conclude that 7 of…

Solar and Stellar Astrophysics · Physics 2014-04-16 S. L. Casewell , S. P. Littlefair , M. R. Burleigh , M. Roy

WIYN/Hydra spectroscopy (at R~15,000) of the moderately metal-rich Praesepe and Hyades open clusters was used to study their main sequence (MS) iron ([Fe/H]) and lithium (A(Li)) abundances. Self-consistent [Fe/H] and Li analyses of these…

Solar and Stellar Astrophysics · Physics 2017-03-08 Jeffrey D. Cummings , Constantine P. Deliyannis , Ryan M. Maderak , Aaron Steinhauer

The disagreement between theoretical predictions and observations for surface lithium abundance in stars is a long-standing problem, which indicates that the adopted physical treatment is still lacking in some points. However, thanks to the…

Solar and Stellar Astrophysics · Physics 2015-06-11 E. Tognelli , S. Degl'Innocenti , P. G. Prada Moroni

Chemical abundances of eight O- and B-type stars are determined from high-resolution spectra obtained with the MIKE instrument on the Magellan 6.5m Clay telescope. The sample is selected from 42 candidates of membership in the Leading Arm…

Lithium abundances in open clusters are a very effective probe of mixing processes, and their study can help to understand the large depletion of lithium in the Sun. Due to its age and metallicity, the open cluster M67 is especially…

Solar and Stellar Astrophysics · Physics 2015-06-04 Giancarlo Pace , Matthieu Castro , Jorge Melendez , Sylvie Theado , Jose-Dias do Nascimento

The surface abundances of the light elements lithium (Li) and beryllium (Be) reveal information about the physical processes taking place in stellar interiors. The investigation of the amount of these two elements in stars in open clusters…

Solar and Stellar Astrophysics · Physics 2022-03-14 Ann Merchant Boesgaard , Michael G. Lum , Ashley Chontos , Constantine P. Deliyannis

We present results of an investigation on a high-galactic latitude sample of late-type field stars selected from the ROSAT All-Sky Survey (RASS). The sample comprises about 200 G, K, and M stars. Lithium abundances were determined for about…

Astrophysics · Physics 2007-05-23 F. -J. Zickgraf , J. Krautter , S. Frink , J. M. Alcala , R. Mujica , E. Covino , M. F. Sterzik
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