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相关论文: Lithium in the lower red giant branch of 5 Galacti…

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The cosmological Li problem is the observed discrepancy between Li abundance, A(Li), measured in Galactic dwarf, old and metal-poor stars (traditionally assumed to be equal to the initial value A(Li)_0), and that predicted by standard Big…

太阳与恒星天体物理 · 物理学 2015-06-22 A. Mucciarelli , M. Salaris , P. Bonifacio , L. Monaco , S. Villanova

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…

太阳与恒星天体物理 · 物理学 2021-09-08 Misa Aoki , Francesca Primas , Luca Pasquini , Achim Weiss , Maurizio Salaris , Daniela Carollo

Lithium abundances for red giants in the GALAH DR3 survey are studied. The rare examples of Li-enriched stars with abundances A(Li) $\geq 1.5$ are confirmed to be He-core burning stars belonging to or evolved from the red clump with similar…

太阳与恒星天体物理 · 物理学 2021-08-25 Deepak , David L. Lambert

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

In this work, we studied the distribution of lithium abundances in giants as a function of stellar mass. We used a sample of 1240 giants common among Kepler photometric and LAMOST medium resolution (R $\approx$ 7500) spectroscopic survey…

太阳与恒星天体物理 · 物理学 2023-02-13 Anohita Mallick , Raghubar Singh , Bacham E. Reddy

Most Globular Clusters are believed to host a single stellar populations. They can thus be considered a good place to study the Spite plateau and probe for possible evolutionary modifications of the Li content. We want to determine the Li…

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…

Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron-Fowler conveyor, but the existence of Li-rich, low-mass red giant…

太阳与恒星天体物理 · 物理学 2016-03-10 Evan N. Kirby , Puragra Guhathakurta , Andrew J. Zhang , Jerry Hong , Michelle Guo , Rachel Guo , Judith G. Cohen , Katia Cunha

The vast majority of stars with mass similar to the Sun are expected to only destroy lithium over the course of their lives, via low-temperature nuclear burning. This has now been supported by observations of hundreds of thousands of red…

太阳与恒星天体物理 · 物理学 2020-07-15 Yerra Bharat Kumar , Bacham E. Reddy , Simon W. Campbell , Sunayana Maben , Gang Zhao , Yuan-Sen Ting

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…

太阳与恒星天体物理 · 物理学 2022-07-20 Julio Chanamé , Marc H. Pinsonneault , Claudia Aguilera-Gómez , Joel C. Zinn

Mapping lithium evolution for evolved stars will provide restrictions and constraints on the fundamental stellar interior physical processes, which further shed light on our understanding of the theory of stellar structure and evolution.…

太阳与恒星天体物理 · 物理学 2021-09-29 Jinghua Zhang , Jian-Rong Shi , Hong-Liang Yan , Yaguang Li , Qi Gao , Chun-Qian Li , Xianfei Zhang , Shuai Liu , Shaolan Bi , Gang Zhao , Yan Li

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,…

Lithium abundances in open clusters are a very effective probe of mixing processes, and their study can help to understand the large depletion of lithium in the Sun. Due to its age and metallicity, the open cluster M67 is especially…

太阳与恒星天体物理 · 物理学 2015-06-04 Giancarlo Pace , Matthieu Castro , Jorge Melendez , Sylvie Theado , Jose-Dias do Nascimento

Standard stellar evolution model predicts a severe depletion of lithium (Li) abundance during the first dredge-up process (FDU). Yet a small fraction of giant stars are still found to preserve a considerable amount of Li in their…

Standard stellar evolution model predicts a severe depletion of lithium (Li) abundance during the first dredge up process (FDU). Yet a small fraction of giant stars are still found to preserve a considerable amount of Li in their…

太阳与恒星天体物理 · 物理学 2020-01-08 Qi Gao , Jian-Rong Shi , Hong-Liang Yan , Tai-Sheng Yan , Mao-Sheng Xiang , Yu-Tao Zhou , Chun-Qian Li , Gang Zhao

Reconstructing the Galactic evolution of lithium (Li) is the main tool used to constrain the source(s) of Li enrichment in the Galaxy. Recent results have suggested a decline in Li at supersolar metallicities, which may indicate reduced…

The presence of multiple populations in globular clusters has been well established thanks to high-resolution spectroscopy. It is widely accepted that distinct populations are a consequence of different stellar generations: intra-cluster…

太阳与恒星天体物理 · 物理学 2015-06-24 V. D'Orazi , R. G. Gratton , G. C. Angelou , A. Bragaglia , E. Carretta , J. C. Lattanzio , S. Lucatello , Y. Momany , A. Sollima , G. Beccari

To alleviate the discrepancy between the prediction of the primordial lithium abundance in the universe and the abundances observed in Pop II dwarfs and subgiant stars, it has been suggested that the stars observable today have undergone…

太阳与恒星天体物理 · 物理学 2015-05-13 K. Lind , F. Primas , C. Charbonnel , F. Grundahl , M. Asplund

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…

星系天体物理 · 物理学 2015-06-05 F. D'Antona , A. D'Ercole , R. Carini , E. Vesperini , P. Ventura

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…

太阳与恒星天体物理 · 物理学 2026-02-27 Wuming Yang , Shuya Dou , Xiangcun Meng , Yaqian Wu , Shaolan Bi