中文
相关论文

相关论文: LAMOST/HRS Spectroscopic Analysis of Two New Li-ri…

200 篇论文

In this paper, we report the discovery of two new super Li-rich K giants: HD~24960 and TYC~1751-1713-1. Based on high resolution ($R\approx 60,000$) spectroscopy, we have derived Li abundance of A(Li)$\approx$4.0~dex for both stars. Other…

太阳与恒星天体物理 · 物理学 2018-11-07 Raghubar Singh , Bacham E. Reddy , Yerra Bharat Kumar

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…

太阳与恒星天体物理 · 物理学 2018-05-23 Yerra Bharat Kumar , Raghubar Singh , B. Eswar Reddy , Gang Zhao

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

Aims: We report the discovery of a young lithium rich giant, HD 16771, in the core-helium burning phase that does not seem to fit existing proposals of Li synthesis near the luminosity function bump or during He-core flash. We aim to…

太阳与恒星天体物理 · 物理学 2016-04-13 Arumalla B. S. Reddy , David L. Lambert

The temperature distribution of field Li-rich red giants suggests the presence of a population of Li-rich red clump (RC) stars. One proposed explanation for this population is that all stars with masses near 2 $M_\odot$ experience a…

太阳与恒星天体物理 · 物理学 2016-08-24 Joleen K. Carlberg , Katia Cunha , Verne V. Smith

The discovery of Li-rich giant has cast a new challenge for the standard stellar evolution models, and to resolve this issue, the number of this type object has been rapidly increased because of the development of worldwide surveys these…

太阳与恒星天体物理 · 物理学 2019-06-05 Yutao Zhou , Hongliang Yan , Jianrong Shi , S. Blanco-Cuaresma , Qi Gao , K. Pan , Xiaodong Xu , Junbo Zhang , Gang Zhao

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…

太阳与恒星天体物理 · 物理学 2015-09-16 M. Adamow , A. Niedzielski , E. Villaver , A. Wolszczan , K. Kowalik , G. Nowak , M. Adamczyk , B. Deka-Szymankiewicz

With an aim to shed light on the origin of Li anomaly observed in a small fraction of red giants, we carried out a spectroscopic study on the observational characteristics of selected 20 bright Li-rich giants, in comparison with a large…

太阳与恒星天体物理 · 物理学 2017-09-20 Yoichi Takeda , Akito Tajitsu

Context: A small number of K-type giants on the red giant branch (RGB) is known to be very rich in lithium (Li). This fact is not accounted for by standard stellar evolution theory. The exact phase and mechanism of Li enrichment is still a…

太阳与恒星天体物理 · 物理学 2015-06-03 Thomas Lebzelter , Stefan Uttenthaler , Maurizio Busso , Mathias Schultheis , Bernhard Aringer

We have gathered near-infrared $zyJ$-band high resolution spectra of nearly 300 field red giant stars with known lithium abundances in order to survey their \species{He}{i} $\lambda$10830 absorption strengths. This transition is an…

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

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…

太阳与恒星天体物理 · 物理学 2020-01-08 Raghubar Singh , Bharat Kumar Yerra , Bacham E. Reddy , Wako Aoki

We present a study of correlations between high Li abundances and strong chromospheric He I 10830 \AA\ absorption line strengths in Kepler field giant stars. Our sample includes 84 giants with detectable solar-like oscillations in their…

太阳与恒星天体物理 · 物理学 2025-01-16 Anohita Mallick , Christopher Sneden , Bacham E. Reddy , Melike Afşar

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

Context: Lithium is a fragile element, which is easily destroyed in the stellar interior. The existence of lithium-rich giants still represents a challenge for stellar evolution models. Aims: We have collected a large database of…

太阳与恒星天体物理 · 物理学 2015-05-27 L. Monaco , S. Villanova , C. Moni Bidin , G. Carraro , D. Geisler , P. Bonifacio , O. A. Gonzalez , M. Zoccali , L. Jilkova

Stellar models predict that lithium (Li) inside a star is destroyed during the first dredge-up phase, yet 1.2% of red giant stars are Li-rich. We aim to uncover possible origins of this population, by analysing 1155 Li-rich giants (A(Li)…

The puzzle of Li-rich giant is still unsolved, contradicting the prediction of the standard stellar models. Although the exact evolutionary stages play a key role in the knowledge of Li-rich giants, a limited number of Li-rich giants have…

太阳与恒星天体物理 · 物理学 2022-06-15 Yutao Zhou , Chun Wang , Hongliang Yan , Yang Huang , Bo Zhang , Yuan-Sen Ting , Huawei Zhang , Jianrong Shi

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

A Li-rich red giant star (2M19411367+4003382) recently discovered in the direction of NGC 6819 belongs to the rare subset of Li-rich stars that have not yet evolved to the luminosity bump, an evolutionary stage where models predict Li can…

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
‹ 上一页 1 2 3 10 下一页 ›