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Related papers: Lithium and binarity in M67

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We have obtained high resolution spectra of $\sim$40 members of M35, determined the Lithium-T$_{\rm{eff}}$ morphology and the distribution of the rotational velocity for G and K stars, and compared them to those of the Pleiades and other…

Astrophysics · Physics 2007-05-23 D. Barrado y Navascues , C. P. Deliyannis , J. R. Stauffer

Lithium abundances, radial velocities and rotational velocities are reported for 20 candidate F, G and K stars of the sparse Coma Berenices open cluster. All the stars are proper-motion selected, and our radial velocities support the…

Astrophysics · Physics 2009-11-06 A. Ford , R. D. Jeffries , D. J. James , J. R. Barnes

Lithium (Li) is a powerful tracer of stellar mixing, gradually depleted in solar twins by non-standard transport below the convective zone. Here, we identify six new solar twins with exceptionally low Li levels that are not explained by…

We investigate lithium depletion in standard stellar models (SSMs) and main sequence (MS) open clusters, and explore the origin of the Li dispersion in young, cool stars of equal mass, age and composition. We first demonstrate that SSMs…

Solar and Stellar Astrophysics · Physics 2015-06-18 Garrett Somers , Marc Pinsonneault

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

M55 (NGC 6809) and NGC 6362 are among the few globular clusters for which masses and radii have been derived to high precision for member binary stars. They also contain RR Lyrae variables which, together with their non-variable…

Solar and Stellar Astrophysics · Physics 2018-08-08 Don A. VandenBerg , Pavel A. Denissenkov

We perform non-LTE calculations of lithium in late-type stars for a wide range of stellar parameters, including quantum mechanical cross-sections for collisions with neutral hydrogen and the negative hydrogen ion. Non-LTE abundance…

Solar and Stellar Astrophysics · Physics 2015-05-13 K. Lind , M. Asplund , P. S. Barklem

In the globular cluster NGC2808, a quasi-standard initial lithium abundance is derived for a red giant belonging to the `extreme' population, characterized by a large helium overabundance, and by abundances of proton capture elements…

We consider WIYN/Hydra spectra of 329 photometric candidate members of the 420-Myr-old open cluster M48, and report Lithium detections or upper limits for 234 members and likely members. The 171 single members define a number of notable…

Solar and Stellar Astrophysics · Physics 2023-07-26 Qinghui Sun , Constantine P. Deliyannis , Aaron Steinhauer , Barbara J. Anthony-Twarog , Bruce A. Twarog

Open clusters serve as laboratories to study and evaluate stellar evolution and Galactic chemical evolution models. Chemical peculiarities, such as lithium-rich giants, are rarely observed in these stellar systems. This work focuses on…

[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 present a suite of binary evolution models with massive primaries (10 $\leq$ M$_1$ $\leq$ 40 M$_\odot$) and periods and mass ratios chosen such that the systems undergo non-conservative mass transfer while the primaries have helium…

Solar and Stellar Astrophysics · Physics 2024-05-10 Michelle Nguyen , Alison Sills

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

A survey of red giants in the globular cluster M3 with the Hydra multi-object spectrograph on the WIYN 3.5-m telescope indicated a prominent Li I 6707 $\AA$ feature in the red giant vZ 1050. Follow-up spectroscopy with the ARC 3.5-m…

Solar and Stellar Astrophysics · Physics 2016-08-04 R. A. Givens , C. A. Pilachowski

We present a new estimate of the lithium abundance in the atmosphere of the brown dwarf LP 944-20. Our analysis is based on a self-consistent analysis of low, intermediate and high resolution optical and near-infrared spectra. We obtain log…

We present the results of mid-resolution spectroscopy in the LiI 6708 AA spectral region of Asymptotic Giant Branch (AGB) stars belonging to young open clusters of the Large Magellanic Cloud. Most stars belong to the clusters NGC 1866 and…

Astrophysics · Physics 2009-11-07 C. Maceroni , V. testa , B. Plez , P. Garcia Lario , F. D'Antona

The current status of observational studies of lithium depletion in open clusters is reviewed, concentrating mainly on G and K type stars. I attempt to answer the following questions: Can the lithium depletion patterns seen in open clusters…

Astrophysics · Physics 2007-05-23 R. D. Jeffries

Detailed simultaneous radiative transfer-statistical equilibrium calculations have been performed for lithium in atmospheres of solar metallicity G-M dwarfs and subgiants. Model atmospheres of stars with $3500 \le \Tf \le 6000$ K, $3.0 \le…

Astrophysics · Physics 2007-05-23 Ya. V. Pavlenko , A. Magazzu

The early F dwarf star ``J37'' in the open cluster NGC6633 shows an unusual pattern of photospheric abundances, including an order of magnitude enhancement of lithium and iron-peak elements, but an under-abundance of carbon. As a…

Astrophysics · Physics 2009-11-13 J. F. Ashwell , R. D. Jeffries , B. Smalley , C. P. Deliyannis , A. Steinhauer , J. R. King

We present lithium abundances for ~50 X-ray selected candidate members of the 30-50 Myr old open clusters IC 2602 and IC 2391. These data enlarge and extend to cooler temperatures previous Li surveys of these clusters by Stauffer et al.…

Astrophysics · Physics 2009-11-06 S. Randich , R. Pallavicini , G. Meola , J. R. Stauffer , Suchitra C. Balachandran
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