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The aim of this work is to search for Li-rich giants in a sample of clusters where planets have been searched, thus we can study the planet engulfment scenario to explain Li replenishment using a proper comparison sample of stars without…

Solar and Stellar Astrophysics · Physics 2016-02-17 E. Delgado Mena , M. Tsantaki , S. G. Sousa , M. Kunitomo , V. Adibekyan , P. Zaworska , N. C. Santos , G. Israelian , C. Lovis

Lithium has confused scientists for decades at almost each scale of the universe. Lithium-rich giants are peculiar stars with lithium abundances over model prediction. A large fraction of lithium-rich low-mass evolved stars are…

We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li…

Astrophysics of Galaxies · Physics 2015-06-05 P. E. Nissen , W. J. Schuster

Given the implications for the origin of Li enhancement in red giants we have reviewed Li-rich classification of KIC~9821622, the only bonafide RGB giant with He inert-core till date, reported as a Li-rich giant by reanalyzing the…

Solar and Stellar Astrophysics · Physics 2020-01-08 Raghubar Singh , Bharat Kumar Yerra , Bacham E. Reddy , Wako Aoki

Recent detection of the isotope $^7$Be (that decays into $^7$Li) in the outburst of classical novae confirms the suggestion made in the 70s that novae could make $^7$Li. We reconsidered the role of novae as producers of Li by means of a…

Solar and Stellar Astrophysics · Physics 2019-01-16 Gabriele Cescutti , Paolo Molaro

The presence of a large amount of Li in giants is still a mystery. Most of the super Li-rich giants reported in recent studies are in the solar metallicity regime. Here, we study the five metal-poor super Li-rich giants (SLRs) from GALAH…

Solar and Stellar Astrophysics · Physics 2024-03-26 Antony Susmitha , Anohita Mallick , Bacham E. Reddy

Lithium rich giant stars are rare objects. For some of them, Li enrichment exceeds abundance of this element found in solar system meteorites, suggesting that these stars have gone through a Li enhancement process. We identified a Li rich…

Solar and Stellar Astrophysics · Physics 2015-09-16 M. Adamow , A. Niedzielski , E. Villaver , A. Wolszczan , K. Kowalik , G. Nowak , M. Adamczyk , B. Deka-Szymankiewicz

Context. The existence of lithium-rich low-mass red giant stars still represents a challenge for stellar evolution models. Stellar clusters are privileged environments for this kind of investigation. Aims. To investigate the chemical…

Solar and Stellar Astrophysics · Physics 2014-03-26 L. Monaco , H. M. J. Boffin , P. Bonifacio , S. Villanova , G. Carraro , E. Caffau , M. Steffen , J. A. Ahumada , Y. Beletsky , G. Beccari

Recent spectroscopic explorations of large Galactic stellar samples stars have revealed the existence of red giants with [$\alpha$/Fe] ratios that are anomalously high, given their relatively young ages. We revisit the GALAH DR3 survey to…

Solar and Stellar Astrophysics · Physics 2022-12-21 S. Borisov , N. Prantzos , C. Charbonnel

As a test of rotationally-induced mixing causing the well-known Li dip in older mid-F dwarfs in the local Galactic disk, we utilize high-resolution and -S/N Keck/HIRESspectroscopy to measure the Li abundance in the components of the1 Gyr,…

Solar and Stellar Astrophysics · Physics 2015-06-16 Patrick Baugh , Jeremy R. King , Constantine P. Deliyannis , Ann Merchant Boesgaard

Known sources of lithium (Li) in the universe include the big bang, novae, asymptotic giant branch stars, and cosmic ray spallation. During their longer-lived evolutionary phases, stars are not expected to add to the Li budget of the…

Solar and Stellar Astrophysics · Physics 2022-07-20 Julio Chanamé , Marc H. Pinsonneault , Claudia Aguilera-Gómez , Joel C. Zinn

We report the discovery of two Li-rich giant stars (fainter than the red giant branch bump) in the stellar system Omega Centauri using GIRAFFE-FLAMES spectra. These two stars have A(Li)=1.65 and 2.40 dex and they belong to the main…

Solar and Stellar Astrophysics · Physics 2019-03-13 A. Mucciarelli , L. Monaco , P. Bonifacio , M. Salaris , X. Fu , S. Villanova

In this letter, we report the discovery of 24 new super Li-rich (A(Li) $\ge$ 3.2) giants of He-core burning phase at red clump region. Results are based on systematic search of a large sample of about 12,500 giants common to the LAMOST…

Solar and Stellar Astrophysics · Physics 2019-06-19 Raghubar Singh , Bacham E. Reddy , Yerra Bharat Kumar , H. M. Antia

We revisit large spectroscopic data sets for field stars from the literature to derive the upper Li envelope in the high metallicity regime in our Galaxy. We take advantage of Gaia EDR3 data and state-of-the-art stellar models to precisely…

Astrophysics of Galaxies · Physics 2021-05-12 C. Charbonnel , S. Borisov , N. Prantzos , P. De Laverny

Context: The stellar production of the light element lithium is still a matter of debate. Aims: We report the detection of low-mass, Li-rich Asymptotic Giant Branch (AGB) stars located in the Galactic bulge. Methods: A homogeneous and…

This contribution presents an overview of the evolution of Li abundances in stars of the Galactic thin and thick discs, from the observational point of view. The focus is on Li abundances obtained by recent projects and surveys. To separate…

Solar and Stellar Astrophysics · Physics 2020-06-23 Rodolfo Smiljanic

In recent years much interest has been shown in the process of thermohaline mixing in red giants. In low and intermediate mass stars this mechanism first activates at the position of the bump in the luminosity function, and has been…

Solar and Stellar Astrophysics · Physics 2015-06-23 John Lattanzio , Lionel Siess , Ross Church , George Angelou , Richard Stancliffe , Carolyn Doherty , Thomas Stephen , Simon Campbell

In this paper we report two new super Li-rich K giants: KIC 2305930 and KIC 12645107 with Li abundances exceeding that of ISM (A(Li) $\geq$ 3.2 dex). Importantly, both the giants have been classified as core He-burning red clump stars based…

Solar and Stellar Astrophysics · Physics 2018-05-23 Yerra Bharat Kumar , Raghubar Singh , B. Eswar Reddy , Gang Zhao

According to standard stellar evolution, lithium is destroyed throughout most of the evolution of low- to intermediate-mass stars. However, a number of evolved stars on the red giant branch (RGB) and the asymptotic giant branch (AGB) are…

Solar and Stellar Astrophysics · Physics 2012-06-14 Stefan Uttenthaler , Thomas Lebzelter , Maurizio Busso , Sara Palmerini , Bernhard Aringer , Mathias Schultheis

We have serendipitously identified the first lithium-rich giant star located close to the red giant branch bump in a globular cluster. Through intermediate-resolution FLAMES spectra we derived a lithium abundance of A(Li)=2.55 (assuming…

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