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相关论文: On the link between rotation, chromospheric activi…

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Lithium abundances and rotation, determined for 120 subgiant stars in Lebre et al. (1999) are analyzed. To this purpose, the evolutionary status of the sample as well as the individual masses have been determined using the HIPPARCOS…

天体物理学 · 物理学 2007-05-23 J. D. do Nascimento , C. Charbonnel , A. Lebre , P. de Laverny , J. R. De Medeiros

We present a study of the evolutionary state of a few lithium-rich giant stars based on the Gaia DR2 parallaxes and photometry. We also investigate the chromospheric activity, the presence of a surface magnetic field, and the radial…

太阳与恒星天体物理 · 物理学 2020-09-09 B. F. O. Gonçalves , J. S. da Costa , L. de Almeida , M. Castro , J. -D. do Nascimento

Precise Li abundances are determined for 54 giant stars mostly evolving across the Hertzsprung gap. We combine these data with rotational velocity and with information related to the deepening of the convective zone of the stars to analyse…

天体物理学 · 物理学 2009-11-10 P. de Laverny , J. D. Jr do Nascimento , A. Lebre , J. R. De Medeiros

The lithium abundances in a few percent of giants exceed the value predicted by the standard stellar evolution models, and the mechanisms of Li enhancement are still under debate. The Large Sky Area Multi-Object Fiber Spectroscopic…

太阳与恒星天体物理 · 物理学 2018-07-18 Y. T. Zhou , J. R. Shi , H. L. Yan , Q. Gao , J. B. Zhang , G. Zhao , K. Pan , Y. B. Kumar

Lithium is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. We present the results of a new large Lithium survey in red giant stars and combine it with surveys from the literature to…

太阳与恒星天体物理 · 物理学 2020-01-08 C. Charbonnel , N. Lagarde , G. Jasniewicz , P. North , M. Shetrone , J. Krugler Hollek , V. V. Smith , R. Smiljanic , A. Palacios , G. Ottoni

We present a study of the lithium abundances of a sample of evolved components of Chromospherically Active Binary Systems. We show that a significant part of them have lithium excesses, independently of their mass and evolutionary stage.…

The orders of magnitude variation in lithium abundances of evolved stars have long been a puzzle. Diluted signals, ambiguous evolutionary states and unknown masses have made it challenging to both map the expected lithium signals and…

太阳与恒星天体物理 · 物理学 2023-07-26 Jamie Tayar , Joleen K. Carlberg , Claudia Aguilera-Gómez , Maryum Sayeed

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…

Lithium is a sensitive probe to mixing processes operating in stellar interiors. For many years, a connection has been suspected to exist between lithium abundances and stellar rotation, presumably the result of rotationally-induced…

太阳与恒星天体物理 · 物理学 2020-09-07 J. Bouvier

Aims. We present a spectroscopic analysis of a sample of evolved stars in M67 (turn-off, subgiant and giant stars) in order to bring observational constraints to evolutionary models taking into account non-standard transport processes.…

太阳与恒星天体物理 · 物理学 2015-03-17 B. L. Canto Martins , A. Lèbre , A. Palacios , P. de Laverny , O. Richard , C. H. F. Melo , J. D. do Nascimento , J. R. De Medeiros

We previously attempted to ascertain why the Li I 6708 line-strengths of Sun-like stars differ so significantly despite the superficial similarities of stellar parameters. We carried out a comprehensive analysis of 118 solar analogs and…

太阳与恒星天体物理 · 物理学 2015-05-18 Y. Takeda , S. Honda , S. Kawanomoto , H. Ando , T. Sakurai

The lithium abundances for 378 G/K giants are derived with non-LTE correction considered. Among these, there are 23 stars that host planetary systems. The lithium abundance is investigated, as a function of metallicity, effective…

太阳与恒星天体物理 · 物理学 2015-06-19 Y. J. Liu , K. F. Tan , L. Wang , G. Zhao , Bun'ei Sato , Y. Takeda , H. N. Li

In the present work, we study the link between rotation and lithium abundance in giant stars of luminosity class III, on the basis of a large sample of single stars of spectral type F, G and K. We shows that giant stars presenting the…

天体物理学 · 物理学 2007-05-23 J. R. De Medeiros , J. D. do Nascimento , S. Sankarankutty , J. M. Costa , M. R. G. Maia

Thanks to the high multiplex and efficiency of Giraffe at the VLT we have been able for the first time to observe the Li I doublet in the Main Sequence (MS) stars of a Globular Cluster. At the same time we observed Li in a sample of…

Preliminary abundances of lithium and a few other elements have been obtained for 31 field Am stars with good Hipparcos parallaxes, as well as for 36 normal A and F stars. Radial and projected rotational velocities were determined as well.…

天体物理学 · 物理学 2009-11-11 P. North , F. Betrix , C. Besson

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…

We present a critical analysis of the nature of the so-called Li-rich RGB stars. For a majority of the stars, we have used Hipparcos parallaxes to determine masses and evolutionary states by comparing their position on the…

天体物理学 · 物理学 2007-05-23 Corinne Charbonnel , Suchitra C. Balachandran

To understand the underlying mechanisms for high lithium abundances among core He-burning or red clump (RC) giants, we analyzed a sample of 5227 RC giants of mass M $\leq$ 2~M$_{\odot}$ using spectra and asteroseismic data. We found 120 RC…

太阳与恒星天体物理 · 物理学 2025-08-06 Raghubar Singh , Bacham E. Reddy , Anohita Mallick , Gang Zhao

Context. As a fragile element, lithium is a sensitive probe of physical processes occurring in stellar interiors. Aims. We aim at investigating the relationship between lithium abundance and rotation rate in low-mass members of the newly…

太阳与恒星天体物理 · 物理学 2020-04-01 J. Arancibia-Silva , J. Bouvier , A. Bayo , P. A. B. Galli , W. Brandner , H. Bouy , D. Barrado

Lithium abundances are presented for a sample of 181 nearby F and G dwarfs with accurate {\it Hipparcos} parallaxes. The stars are on circular orbits about the Galactic centre and, hence, are identified as belonging to the thin disk. This…

天体物理学 · 物理学 2009-11-10 David L. Lambert , Bacham E. Reddy
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