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Related papers: Lithium-rich giants in the Galactic thick disk

200 papers

We present the main results derived from a chemical analysis carried out on a large sample of galactic O-rich AGB stars using high resolution optical spectroscopy (R~40,000-50,000) with the intention of studying their lithium abundances…

Astrophysics · Physics 2009-11-13 D. A. Garcia-Hernandez , P. Garcia-Lario , B. Plez , A. Manchado , F. D'Antona , J. Lub , H. Habing

The observed lithum (Li) abundance of Galactic halo stars mainly fall within the range of 2.0--2.4 dex. This nearly constant value, known as the Spite plateau, is approximately a factor of three lower than the value predicted from cosmic…

Solar and Stellar Astrophysics · Physics 2026-02-27 Wuming Yang , Shuya Dou , Xiangcun Meng , Yaqian Wu , Shaolan Bi

Super Li-rich stars form a very small and enigmatic group whose existence cannot be explained in terms of the standard stellar evolution theory. The goal of our study is to check the reality of this group of cool giants based on an…

Solar and Stellar Astrophysics · Physics 2016-02-08 L. S. Lyubimkov , B. M. Kaminsky , V. G Metlov , Ya. V. Pavlenko , D. B. Poklad , T. M. Rachkovskaya

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

The presence of the lithium-6 isotope in some metal-poor stars is a matter of surprise because of the high values observed. Non-standard models of Big Bang nucleosynthesis and pre-Galactic cosmic ray fusion and spallation have been proposed…

Solar and Stellar Astrophysics · Physics 2009-09-29 A. E. Garcia Perez , W. Aoki , S. Inoue , S. G. Ryan , T. K. Suzuki , M. Chiba

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

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

Using high-resolution, high quality spectra we investigate the presence of $^6$Li in two lithium-poor stars that host extrasolar planetary systems. We present improved atomic and molecular line lists for the region in the vicinity of the…

Astrophysics · Physics 2009-11-10 Avi M. Mandell , Jian Ge , Norm Murray

Our aim was to determine the initial Li content of two clusters of similar metallicity but very different ages, the old open cluster NGC 2243 and the metal-rich globular cluster NGC 104. We compared the lithium abundances derived for a…

Solar and Stellar Astrophysics · Physics 2021-09-08 Misa Aoki , Francesca Primas , Luca Pasquini , Achim Weiss , Maurizio Salaris , Daniela Carollo

The emergence of the disc in our Galaxy and the relation of the thick and thin disc formation and evolution is still a matter of debate. The chemo-dynamical characterization of disc stars is key to resolve this question, in particular at…

We present the first detailed abundance analysis of the metal-poor giant HKII 17435-00532. This star was observed as part of the University of Texas long-term project "Chemical Abundances of Stars in the Halo" (CASH). A spectrum was…

We provide detailed abundance analyses of 8 candidate super-metal-rich stars. Five of them are confirmed to have [Fe/H] > 0.2 dex, the generally-accepted limit for super-metal-richness. Furthermore, we derive abundances of several elements…

Astrophysics · Physics 2007-05-23 Sofia Feltzing , Guillermo Gonzalez

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

Observations of interstellar lithium provide a valuable complement to studies of lithium in Pop I and Pop II stars. Large corrections for unseen LiII and for non-gas phase lithium have provided obstacles to using interstellar data for…

Astrophysics · Physics 2009-10-28 GARY STEIGMAN

High-dispersion spectra centered on the Li 6708 A line have been obtained for 70 potential members of the open cluster NGC 3680, with an emphasis on stars in the turnoff region. A measurable Li abundance has been derived for 53 stars, 39 of…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. J. Anthony-Twarog , C. P. Deliyannis , B. A. Twarog , K. V. Croxall , J. D. Cummings

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

With its origin coming from several sources (Big Bang, stars, cosmic rays) and given its strong depletion during its stellar lifetime, the lithium element is of great interest as its chemical evolution in the Milky Way is not well…

Despite the large number of studies focused on the characterisation of Li-rich stars and understanding the mechanisms leading to such enrichment, their origin remains a mystery. Magnetic activity, particularly the phenomena usually…

Solar and Stellar Astrophysics · Physics 2024-08-13 Inês Rolo , Elisa Delgado Mena , Maria Tsantaki , João Gomes da Silva

The pre-Galactic abundance of lithium offers a unique window into non-thermal cosmological processes. The primordial Li abundance is guaranteed to be present and probes big bang nucleosynthesis (BBN), while an additional Li component is…

Astrophysics · Physics 2007-05-23 Tijana Prodanovic , Brian D. Fields

We aim to quantify the chemical and kinematical properties of the Galactic disks with a sample of 119,558 giant stars having abundances and 3D velocities taken or derived from the APOGEE DR17 and Gaia EDR3 catalogs. The Gaussian Mixture…

Astrophysics of Galaxies · Physics 2022-04-20 Guozhen Hu , Zhengyi Shao