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

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The Teff location of Pre-Main Sequence (PMS) evolutionary tracks depends on the treatment of over-adiabaticity. We present here the PMS evolutionary tracks computed by using the mixing length theory of convection (MLT) in which the…

Astrophysics · Physics 2009-11-11 Josefina Montalban , Francesca D'Antona

We address the existence and origin of the lithium (Li) desert, a region in the Li - T_eff plane sparsely populated by stars. Here we analyze some of the explanations that have been suggested for this region, including mixing in the late…

Solar and Stellar Astrophysics · Physics 2018-06-13 Claudia Aguilera-Gómez , Iván Ramírez , Julio Chanamé

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

We present Li abundances for 14 solar-type stars in the intermediate age (~ 2 Gyr) clusters IC 4651 and NGC 3680. The log n(Li) vs. effective temperature distributions are compared with those of the similar age cluster NGC 752, of the…

Astrophysics · Physics 2007-05-23 S. Randich , L. Pasquini , R. Pallavicini

Accurately known stellar lithium abundances may be used to shed light on a variety of astrophysical phenomena such as Big Bang nucleosynthesis, radial migration, ages of stars and stellar clusters, and planet engulfment events. We present a…

Solar and Stellar Astrophysics · Physics 2020-10-30 E. Wang , T. Nordlander , M. Asplund , A. M. Amarsi , K. Lind , Y. Zhou

Aims. Exoplanet-host stars (EHS) are known to present superficial chemical abundances different from those of stars without any detected planet (NEHS). EHS are, on the average, overmetallic compared to the Sun. The observations also show…

Astrophysics · Physics 2009-11-13 M. Castro , S. Vauclair , O. Richard , N. C. Santos

Rapidly growing datasets from stellar spectroscopic surveys are providing unprecedented opportunities to analyse the chemical evolution history of our Galaxy. However, spectral analysis requires accurate modelling of synthetic stellar…

Solar and Stellar Astrophysics · Physics 2024-03-29 J. W. E. Mallinson , K. Lind , A. M. Amarsi , K. Youakim

Lithium abundance in most of the warm metal-poor main sequence stars shows a constant plateau (A(Li)~2.2 dex) and then the upper envelope of the lithium vs. metallicity distribution increases as we approach solar metallicity. Meteorites,…

In this study, we explore the evolution of lithium in giant stars based on data assembled from the literature on asteroseismology and Li abundances for giants. Our final sample of 187 giants consists of 44 red giant branch (RGB), 140 core…

Solar and Stellar Astrophysics · Physics 2021-05-07 Deepak , David L. Lambert

We investigate the properties of 1262 red giant stars with high photospheric abundances of lithium observed by the GALAH and \Ktwo-HERMES surveys, and discuss them in the context of proposed mechanisms for lithium enrichment and…

Investigating the chemical homogeneity of stars born from the same molecular cloud at virtually the same time is very important for our understanding of the chemical enrichment of the interstellar medium and with it the chemical evolution…

Stellar clusters are open windows to understand stellar evolution. Specifically, the change with time and the dependence on mass of different stellar properties. As such, they are our laboratories where different theories can be tested. We…

Solar and Stellar Astrophysics · Physics 2016-12-14 D. Barrado , H. Bouy , J. Bouvier , E. Moraux , L. M. Sarro , E. Bertin , J. C. Cuillandre , J. R. Stauffer , J. Lillo-Box , A. Pollock

Measurements of lithium abundances in solar-type stars have shown that standard models of stellar evolution are incapable of explaining the observed depletion as a function of stellar age. Beryllium is one of the lightest elements that can…

We present the results of a photometric and spectroscopic survey of cool M dwarf candidates in the young open cluster NGC 2547. Using the 2dF fiber spectrograph, we have searched for the luminosity at which lithium remains unburned in an…

In this review I briefly discuss the theory of pre-main-sequence (PMS) Li depletion in low-mass (0.075<M<1.2 Msun) stars and highlight those uncertain parameters which lead to substantial differences in model predictions. I then summarise…

Astrophysics · Physics 2015-12-09 R. D. Jeffries

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

We probe the spatial and dynamical structure of the old open cluster M67 using photometric data from the Sloan Digital Sky Survey's sixth data release. Making use of an optimal contrast, or matched filter, algorithm, we map the distribution…

Astrophysics of Galaxies · Physics 2015-05-14 James R. A. Davenport , Eric L. Sandquist

We make use of high resolution, high signal-to-noise ratio spectra of 12 turn-off stars in the metal-poor globular cluster NGC 6397 to measure its lithium content. We conclude that they all have the same lithium abundance A(Li) = 2.34 with…

Globular cluster stars show chemical abundance patterns typical of hot-CNO processing. Lithium is easily destroyed by proton capture in stellar environments, so its abundance may be crucial to discriminate among different models proposed to…

Astrophysics of Galaxies · Physics 2015-06-05 F. D'Antona , A. D'Ercole , R. Carini , E. Vesperini , P. Ventura

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