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Related papers: Lithium evolution in intermediate age and old open…

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We estimate cluster ages from lithium depletion in five pre-main-sequence groups found within 100 pc of the Sun: TW Hydrae Association, Eta Chamaeleontis Cluster, Beta Pictoris Moving Group, Tucanae-Horologium Association and AB Doradus…

We present detailed chemical compositions of 10 red giant star members of the Galactic (open) cluster NGC 752, derived from high-resolution (R $\approx$ 60,000), high signal-to-noise ($S/N$ $\geq$ 140) spectra. We confirmed cluster…

Solar and Stellar Astrophysics · Physics 2015-06-23 G. Böcek Topcu , M. Afşar , M. Schaeuble , C. Sneden

In the framework of the study of the Galactic metallicity gradient and its time evolution, we present new high-resolution spectroscopic observations obtained with FLAMES and the fiber link to UVES at VLT of three open clusters (OCs) located…

We present a revised metallicity distribution of dwarfs in the solar neighbourhood. This distribution is centred on solar metallicity. We show that previous metallicity distributions, selected on the basis of spectral type, are biased…

Astrophysics · Physics 2009-11-06 Misha Haywood

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…

In this paper we investigate statistical equilibrium of Ti in the atmospheres of late-type stars. The Ti I/Ti II level populations are computed with available experimental atomic data, except for photoionization and collision induced…

Solar and Stellar Astrophysics · Physics 2015-05-20 Maria Bergemann

Of all the light elements, lithium is the most sensitive indicator of stellar evolution. This review discusses current data on the abundance of lithium in the atmospheres of A-, F-, G-, and K-stars of different types, as well as the…

Solar and Stellar Astrophysics · Physics 2017-01-23 L. S. Lyubimkov

We present the results of a photometric and spectroscopic study of the white dwarf candidate members of the intermediate age open clusters NGC3532 and NGC2287. Of the nine objects investigated, it is determined that six are probable members…

Solar and Stellar Astrophysics · Physics 2009-11-13 P. D. Dobbie , R. Napiwotzki , M. R. Burleigh , K. Williams , R. G. Sharp , M. A. Barstow , S. L. Casewell , I. Hubeny

NGC 362 is a non-common Type II Galactic globular cluster, showing a complex pseudo two-color diagram or 'chromosome map'. The clear separation of its stellar populations in the color-magnitude diagram and the distribution of the giant…

Astrophysics of Galaxies · Physics 2022-07-13 C. Vargas , S. Villanova , D. Geisler , C. Muñoz , L. Monaco , J. O'Connell , Ata Sarajedini

Open clusters have long been used to illuminate both stellar evolution and Galactic evolution. The oldest clusters, though rather rare, can reveal the chemical and nucleosynthetic processes early in the history of the Galaxy. We have…

Astrophysics of Galaxies · Physics 2015-05-13 Ann Merchant Boesgaard , Elizabeth E. C. Jensen , Constantine P. Deliyannis

We present spectroscopy of two clusters in the dwarf irregular galaxy NGC 6822. From these we deduce an age for Cluster VII of 11 Gyr and [Fe/H] = -1.95 +/- 0.15 dex. Cluster VII appears to be an analog of the metal-poor galactic globular…

Astrophysics · Physics 2009-10-30 Judith G. Cohen , John P. Blakeslee

We present the initial results of a study of the surface lithium abundance in a sample of low-mass members (M~0.4-1.0 Msun) of the Orion Nebula Cluster (ONC) that provide an independent clock to estimate stellar ages. We report discovery of…

Astrophysics · Physics 2009-11-11 F. Palla , S. Randich , E. Flaccomio , R. Pallavicini

We present a chemical abundance study of three inner old halo clusters NGC 6287, NGC 6293, and NGC 6541, finding [Fe/H] = -2.01 +/- 0.05, -1.99 +/- 0.02, and -1.76 +/- 0.02, respectively, and our metallicity measurements are in good…

Astrophysics · Physics 2009-11-07 Jae-Woo Lee , Bruce W. Carney

Accurate stellar parameters of stars in open clusters can help constrain models of stellar structure and evolution. Here we wish to determine the age and metallicity content of the open cluster NGC 2506. To this end we investigated three…

We aim to constrain the mixing processes in low-mass stars by investigating the behaviour of the Li surface abundance after the main sequence. We take advantage of the data from the sixth internal data release of Gaia-ESO, idr6, and from…

We utilize the robust membership determination algorithm, ML-MOC, on the precise astrometric and deep photometric data from Gaia Early Data Release 3 within a region of radius 5$^{\circ}$ around the center of the intermediate-age galactic…

Astrophysics of Galaxies · Physics 2021-05-26 Souradeep Bhattacharya , Manan Agarwal , Khushboo K. Rao , Kaushar Vaidya

In the framework of a project aiming at deriving in a homogeneous way the properties (age, distance, reddening and detailed chemical abundances) of a large sample of old open clusters, we present here the metal abundance and the abundance…

Astrophysics · Physics 2009-11-13 Eugenio Carretta , Angela Bragaglia , Raffaele Gratton

The Li abundance observed in pre-main sequence and main sequence late-type stars is strongly age-dependent, but also shows a complex pattern depending on several parameters, such as rotation, chromospheric activity and metallicity. The best…

Determinations of beryllium abundance in stars, together with lithium, provide a key tool to investigate the so far poorly understood extra-mixing processes at work in stellar interiors. We measured Be in three open clusters,complementing…

Astrophysics · Physics 2009-11-13 S. Randich , F. Primas , L. Pasquini , P. Sestito , R. Pallavicini

We present the results of combined optical and near-infrared photometry for the globular cluster systems of the giant ellipticals IC 4051 and NGC 3311. We use the reduced age-metallicity degeneracy in (V-I) vs.(V-H) color-color diagrams to…

Astrophysics · Physics 2009-11-11 M. Hempel , D. Geisler , D. W. Hoard , W. E. Harris