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Related papers: Lithium in M67: From the main sequence to the red …

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We have determined Li abundances in 55 metal-poor (3.6 < [Fe/H] < -0.7) stars with extreme orbital kinematics. We find the Li abundance in the Li-plateau stars and examine its decrease in low-temperature, low-mass stars. The Li observations…

Astrophysics · Physics 2009-11-13 Ann Merchant Boesgaard , Alex Stephens , Constantine P. Deliyannis

Evolutionary models taking into account radiative accelerations, thermal diffusion, and gravitational settling for 28 elements, including all those contributing to OPAL stellar opacities, have been calculated for solar metallicity stars of…

Astrophysics · Physics 2009-11-10 G. Michaud , O. Richard , J. Richer , Don A. VandenBerg

Based on radiation hydrodynamics modeling of stellar convection zones, a diffusion scheme has been devised describing the downward penetration of convective motions beyond the Schwarzschild boundary (overshoot) into the radiative interior.…

Astrophysics · Physics 2009-10-30 T. Bloecker , H. Holweger , B. Freytag , F. Herwig , H. -G. Ludwig , M. Steffen

We derive lithium abundances in 53 T Tauri stars (TTS), concentrating on weak-line TTS. Our study gives the following results: 1)At luminosities $\ge 0.9 L\sun$ the Li abundances are remarkably uniform, with a mean value, log~N(Li)=3.1,…

Astrophysics · Physics 2019-08-17 E. L. Martin , R. Rebolo , A. Magazzu , Ya. V. Pavlenko

We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated by…

Solar and Stellar Astrophysics · Physics 2017-08-16 I. Baraffe , J. Pratt , T. Goffrey , T. Constantino , D. Folini , M. V. Popov , R. Walder , M. Viallet

We present the results of a spectroscopic survey of X-ray selected, low-mass candidate members of the young open cluster NGC 2547. Using a combination of photometry, spectroscopic indices and radial velocities we refine our candidate list…

Astrophysics · Physics 2009-11-07 R. D Jeffries , J. M. Oliveira , D. Barrado y Navascues , J. R. Stauffer

The lithium present in the photospheres of solar-type stars is transported to the inner parts by convection, reaching regions even somewhat below the convection zone, by non-standard transport mechanisms. In stars with deeper convective…

Solar and Stellar Astrophysics · Physics 2023-05-04 Giulia Martos , Jorge Meléndez , Anne Rathsam , Gabriela Carvalho Silva

We have performed a new and homogeneous analysis of all the Li data available in the literature for main sequence stars (spectral-types from late F to K) in open clusters. In the present paper we focus on a detailed investigation of MS Li…

Astrophysics · Physics 2009-11-11 P. Sestito , S. Randich

The light element lithium is formed by nucleosynthesis during the Big Bang. Its abundance can help to define the parameters of the early universe. To find this primordial value, it is necessary to determine Li abundances in the oldest stars…

Solar and Stellar Astrophysics · Physics 2023-07-28 Ann Merchant Boesgaard , Constantine P. Deliyannis

Context. The benchmark open cluster M67 is known to have solar metallicity and similar age as the Sun. It thus provides us a great opportunity to study the properties of solar twins, as well as the evolution of Sun-like stars. Aims.…

Solar and Stellar Astrophysics · Physics 2019-07-10 F. Liu , M. Asplund , D. Yong , S. Feltzing , A. Dotter , J. Meléndez , I. Ramírez

We propose here that the lithium decrease at super-solar metallicities observed in high resolution spectroscopic surveys can be explained by the interplay of mixed populations, coming from the inner regions of the Milky Way disc. The lower…

Astrophysics of Galaxies · Physics 2019-03-13 G. Guiglion , C. Chiappini , D. Romano , F. Matteucci , F. Anders , M. Steinmetz , I. Minchev , P. de Laverny , A. Recio-Blanco

Lithium abundances for red giants in the GALAH DR3 survey are studied. The rare examples of Li-enriched stars with abundances A(Li) $\geq 1.5$ are confirmed to be He-core burning stars belonging to or evolved from the red clump with similar…

Solar and Stellar Astrophysics · Physics 2021-08-25 Deepak , David L. Lambert

[abridged] Previous analyses of lithium abundances in main sequence and red giant stars have revealed the action of mixing mechanisms other than convection in stellar interiors. Beryllium abundances in stars with lithium abundance…

Solar and Stellar Astrophysics · Physics 2015-05-14 Rodolfo Smiljanic , Luca Pasquini , Corinne Charbonnel , Nadege Lagarde

We aim to determine abundances of Li, O and Na in a sample of of 110 turn-off (TO) stars, in order to study the evolution of light elements in this cluster and to put our results in perspective with observations of other globular and open…

Solar and Stellar Astrophysics · Physics 2014-05-28 V. Dobrovolskas , A. Kučinskas , P. Bonifacio , S. A. Korotin , L. Sbordone , E. Caffau , D. Prakapavičius , M. Steffen , H. -G. Ludwig , F. Royer

There has been recent progress in the study of the angular momentum evolution of low mass stars (Krishnamurthi et al 1997a). Theoretical models can now be constructed which reproduce the angular momentum evolution of low mass open cluster…

Astrophysics · Physics 2007-05-23 M. H. Pinsonneault , V. K. Narayanan , G. Steigman , T. P. Walker

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

This paper presents the chemical abundance analysis of 217 stars in the metal-poor globular cluster NGC 6752, distributed from the turn-off to the lower red giant branch. Aluminium and Lithium abundances were derived through spectral…

Solar and Stellar Astrophysics · Physics 2022-02-09 J. Schiappacasse-Ulloa , S. Lucatello , M. J. Rain , A. Pietrinferni

We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li…

Astrophysics of Galaxies · Physics 2015-06-05 P. E. Nissen , W. J. Schuster

We determined the metallicity ([Fe/H]), together with O, Na, Mg, Al, Si, Ca, Ti, Cr and Ni abundances for a sample of 10 unevolved or slightly evolved stars belonging to the open cluster M 67. We find an average metallicity [Fe/H]=0.03 +/-…

Astrophysics · Physics 2009-11-11 S. Randich , P. Sestito , F. Primas , R. Pallavicini , L. Pasquini

We present new high resolution spectroscopic observations of the intermediate age (~2 Gyr) open cluster NGC 752. We investigate the Li vs. Teff distribution and we obtain a new accurate determination of the cluster metallicity. We compare…

Astrophysics · Physics 2009-11-10 P. Sestito , S. Randich , R. Pallavicini
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