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相关论文: Lithium Enrichment Signatures of Planetary Engulfm…

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Throughout a planetary system's formation evolution, some of the planetary material may end up falling into the host star and be engulfed by it, leading to a potential variation of the stellar composition. The present study explores how…

地球与行星天体物理 · 物理学 2025-01-08 B. M. T. B. Soares , V. Adibekyan , C. Mordasini , M. Deal , S. G. Sousa , E. Delgado-Mena , N. C. Santos , C. Dorn

This work aims to investigate the behaviour of the lithium abundance in stars with and without detected planets. Our study is based on a sample of 1332 FGK main-sequence stars with measured lithium abundances, for 257 of which planets were…

太阳与恒星天体物理 · 物理学 2024-02-05 F. Llorente de Andrés , R. de la Reza , P. Cruz , D. Cuenda-Muñoz , E. J. Alfaro , C. Chavero , C. Cifuentes

A recent study of Li abundances in field red giant stars suggested that the phenomenon of enriched surface Li may be a short-lived phase of red clump evolution for stars with masses near 2 M_sun. Although the exact mechanism for generating…

太阳与恒星天体物理 · 物理学 2014-08-13 Joleen K. Carlberg , Katia Cunha , Verne V. Smith

We address the existence and origin of the lithium (Li) desert, a region in the Li - T_eff plane sparsely populated by stars. Here we analyze some of the explanations that have been suggested for this region, including mixing in the late…

太阳与恒星天体物理 · 物理学 2018-06-13 Claudia Aguilera-Gómez , Iván Ramírez , Julio Chanamé

We report results from lithium abundance determinations using high resolution spectral analysis of the 107 metal-rich stars from the Calan-Hertfordshire Extrasolar Planet Search programme. We set out to understand the lithium distribution…

太阳与恒星天体物理 · 物理学 2018-03-21 Ya. V. Pavlenko , J. S. Jenkins , O. M. Ivanyuk , H. R. A. Jones , B. M. Kaminsky , Yu. P. Lyubchik , L. A. Yakovina

Lithium abundance derived in metal-poor main sequence stars is about three times lower than the value of primordial Li predicted by the standard Big Bang nucleosynthesis when the baryon density is taken from the CMB or the deuterium…

太阳与恒星天体物理 · 物理学 2015-06-22 Xiaoting Fu , Alessandro Bressan , Paolo Molaro , Paola Marigo

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

About ten percent of Sun-like ($1$-$2 M_\odot$) stars will engulf a $1$-$10 M_{\rm J}$ planet as they expand during the red giant branch (RGB) or asymptotic giant branch (AGB) phase of their evolution. Once engulfed, these planets…

地球与行星天体物理 · 物理学 2023-06-28 Christopher E. O'Connor , Lars Bildsten , Matteo Cantiello , Dong Lai

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…

太阳与恒星天体物理 · 物理学 2024-08-13 Inês Rolo , Elisa Delgado Mena , Maria Tsantaki , João Gomes da Silva

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

Recent developments in asteroseismology -- thanks to space-based missions such as {\it CoRoT} and {\it Kepler} -- provide handles on those properties of stars that were either completely inaccessible in the past or only poorly measured.…

太阳与恒星天体物理 · 物理学 2019-09-04 Kuldeep Verma , Víctor Silva Aguirre

We report 20 new lithium-rich giants discovered within the Gaia-ESO Survey, including the first Li-rich giant with evolutionary stage confirmed by CoRoT data. Atmospheric parameters and abundances were derived in model atmosphere analyses…

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

This study investigates the temporal and spatial variations in lithium abundance within the Milky Way using a sample of 22,034 main-sequence turn-off (MSTO) stars and subgiants, characterised by precise stellar ages, 3D NLTE (non-local…

星系天体物理 · 物理学 2024-11-21 Tiancheng Sun , Shaolan Bi , Xunzhou Chen , Yuxi , Lu , Yuqin Chen , Ming-Yi Ding , Jianrong Shi , Hongliang Yan , Zhishuai Ge

We have investigated the abundance anomalies of lithium for stars with planets in the temperature range of 5600--5900 K reported by Israelian and coworkers, as compared to 20 normal stars at the same temperature and metallicity ranges. Our…

天体物理学 · 物理学 2010-11-11 Y. Q. Chen , G. Zhao

(Abridged) We contribute to our understanding of the evolution of young intermediate-mass stars by providing a comprehensive analysis of their lithium (Li) content. A sample of 71 intermediate-mass T Tauri (IMTT) and Herbig stars within the…

In this article, we speculate on the possible mechanisms for Li enhancement origin in RGB stars based on a large data set of around 340,299 stars collected from the GALAH survey combined with the Gaia astrometry. Data has 51,982 low mass…

太阳与恒星天体物理 · 物理学 2019-01-29 Deepak , Bacham Eswar Reddy

The surface abundance of lithium on the Sun is 140 times less than protosolar, yet the temperature at the base of the surface convective zone is not hot enough to burn Li. A large range of Li abundances in solar type stars of the same age,…

We report the discovery of a unique object, BD+48 740, a lithium overabundant giant with A(Li)=2.33 +/- 0.04 (where A(Li) = log(n_Li/n_H) + 12), that exhibits radial velocity (RV) variations consistent with a 1.6 M_J companion in a highly…

太阳与恒星天体物理 · 物理学 2015-06-05 M. Adamów , A. Niedzielski , E. Villaver , G. Nowak , A. Wolszczan

The depletion of lithium during the pre-main sequence and main sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. In the…

天体物理学 · 物理学 2011-05-05 M. H. Pinsonneault , T. P. Walker , G. Steigman , V. K. Narayanan