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There is evidence in the 125-Myr Pleiades cluster, and more recently in the 5-Myr NGC 2264 cluster, that rotation plays a key role in the Lithium (Li) depletion processes among low-mass stars. Fast rotators appear to be less Li-depleted…

Solar and Stellar Astrophysics · Physics 2016-11-30 S. Messina , A. C. Lanzafame , G. A. Feiden , M. Millward , S. Desidera , A. Buccino , I. Curtis , E. Jofre' , P. Kehusmaa , B. J. Medhi , B. Monard , R. Petrucci

We report discovery of significant depletion of Li on the surfaces of F dwarf stars in the 150-Myr-old open cluster M35, analagous to a feature in the 700-Myr-old Hyades cluster that has been referred to as the ``Li gap.'' We have caught…

Astrophysics · Physics 2009-11-10 Aaron Steinhauer , Constantine P. Deliyannis

The present work aims to examine in detail the depletion of lithium in solar twins to better constrain stellar evolution models and investigate its possible connection with exoplanets. We employ spectral synthesis in the region of the…

Solar and Stellar Astrophysics · Physics 2019-03-20 M. Carlos , J. Melendez , L. Spina , L. A. dos Santos , M. Bedell , I. Ramirez , M. Asplund , J. L. Bean , D. Yong , J. Yana Galarza , A. Alves-Brito

We determine lithium (Li) abundances for solar twins in the M67 open cluster to add valuable information about the correlation between Li depletion and stellar age and, then, better understand stellar structure and evolution. We use high…

Solar and Stellar Astrophysics · Physics 2020-01-08 Marilia Carlos , Jorge Melendez , Jose-Dias do Nascimento , Matthieu Castro

Intermediate resolution spectroscopy from the ESO Very Large Telescope is analysed for 63 photometrically selected low-mass (0.08-0.30 Msun) candidates of the open cluster NGC 2547. We have confirmed membership for most of these stars using…

Astrophysics · Physics 2009-11-10 R. D. Jeffries , J. M. Oliveira

We analyze the non-standard mixing history of the solar twins HIP 55459, HIP 79672, HIP 56948, HIP 73815, and HIP 100963, to determine as precisely as possible their mass and age. We computed a grid of evolutionary models with non-standard…

Solar and Stellar Astrophysics · Physics 2015-05-13 J. D. do Nascimento , M. Castro , J. Melendez , M. Bazot , S. Theado , G. F. Porto de Mello , J. R. De Medeiros

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 present novel tests of pre$-$main-sequence models based on individual dynamical masses for the M7 binary LSPM J1314+1320AB. Joint analysis of our Keck adaptive optics astrometric monitoring along with Very Long Baseline Array radio data…

Solar and Stellar Astrophysics · Physics 2016-08-17 Trent J. Dupuy , Jan Forbrich , Aaron Rizzuto , Andrew W. Mann , Kimberly Aller , Michael C. Liu , Adam L. Kraus , Edo Berger

We present an extensive study of lithium abundances in dwarf components of chromospherically active binary stars (CABS). Since most of these binaries have known radii, masses and ages, this kind of data is especially useful for comparisons…

The theory of substellar evolution predicts that there is a sharp mass boundary between lithium and non-lithium brown dwarfs, not far below the substellar-mass limit. The imprint of thermonuclear burning is carved on the surface lithium…

Solar and Stellar Astrophysics · Physics 2021-11-03 Eduardo L. Martín , Nicolas Lodieu , Carlos del Burgo

We present high-resolution spectroscopic observations of the \ion{Li}{1} resonance line in a sample of 62 stars that belong to 31 common-proper motion pairs with twin F or G-type components. Photospheric abundances of lithium were derived…

Astrophysics · Physics 2009-11-07 Eduardo L. Martin , Gibor Basri , Yakiv Pavlenko , Yuri Lyubchik

The behavior of lithium (Li) in Population I main sequence stars challenges standard stellar theory. Two phenomena stand out: the solar Li problem which extends to Li depletion in solar analogs and the Li dip observed in mid-F stars within…

Solar and Stellar Astrophysics · Physics 2025-08-28 Xuefeng Li , Jianrong Shi , Yan Li , Hongliang Yan , Jinghua Zhang

The so-called lithium depletion boundary (LDB) provides a secure and independent tool for deriving the ages of young open clusters.In this context, our goal is to determine membership for a sample of 147 photometrically selected candidates…

Astrophysics · Physics 2009-11-13 S. Manzi , S. Randich , W. J. de Wit , F. Palla

We have carried out a high resolution spectroscopic survey of the 220-250 Myr old cluster NGC 6475: our main purpose is to investigate Li evolution during the early stages of the Main Sequence. We have determined Li abundances for 33 late F…

Astrophysics · Physics 2009-11-07 Paola Sestito , Sofia Randich , Jean-Claude Mermilliod , Roberto Pallavicini

We provide *lambda*6708 Li 1 measurements in 37 metal-poor stars, most of which are poorly-studied or have no previous measurements, from high-resolution and high-S/N spectroscopy obtained with the McDonald Observatory 2.1m and 2.7m…

Solar and Stellar Astrophysics · Physics 2015-06-03 Marc Schaeuble , Jeremy R. King

[Context]. The standard solar model fails to predict the very low lithium abundance in the Sun, which is much lower than the proto-solar nebula. This Li problem has been debated for decades, and it has been ascribed either to planet…

Solar and Stellar Astrophysics · Physics 2014-07-09 Jorge Melendez , Lucas Schirbel , TalaWanda R. Monroe , David Yong , Ivan Ramirez , Martin Asplund

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…

The determination of lithium abundances in stars of young clusters have shown that they deplete Li by different degrees during their pre-main sequence phase. Beryllium abundances are complementary to the lithium ones, and can help tracing…

Solar and Stellar Astrophysics · Physics 2015-05-30 Rodolfo Smiljanic , Sofia Randich , Luca Pasquini

The depletion of lithium during the pre-main sequence and main sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. In the…

Astrophysics · Physics 2011-05-05 M. H. Pinsonneault , T. P. Walker , G. Steigman , V. K. Narayanan

A study of the lithium abundances in binaries of the old open cluster M67 is presented. Abundances were estimated using curves of growth and equivalent widths of the LiI6707.8 \AA{} doublet. We have corrected of the effects of the companion…

Astrophysics · Physics 2007-05-23 D. Barrado y Navascues , J. R. Stauffer , S. Balachandran