Two New Super Li-rich Core He-burning Giants: A New Twist to the Long Tale of Li Enhancement in K Giants

doi:10.3847/2041-8213/aac16f

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	Two New Super Li-rich Core He-burning Giants: A New Twist to the Long Tale of Li Enhancement in K Giants
	Kumar,Yerra Bharat 1; Singh,Raghubar 2; Reddy,B. Eswar 2; Zhao,Gang 1,3
刊名	The Astrophysical Journal Letters
	2018-05-11
卷号	858 期号:2
关键词	stars: abundances stars: evolution stars: individual (KIC2305930, KIC12645107) stars: late-type stars: low-mass
ISSN号	2041-8205
DOI	10.3847/2041-8213/aac16f
英文摘要	Abstract In this Letter we report two new super Li-rich K giants, KIC2305930 and KIC12645107, with Li abundances exceeding that of the interstellar medium (ISM; A(Li)?≥?3.2?dex). Importantly, both of the giants have been classified as core He-burning red clump (RC) stars based on asteroseismic data from Kepler mission. Also, both of the stars are found to be low mass (M ≈ 1.0 M⊙), which, together with an evidence of their evolutionary status of being RC stars, implies that the stars have gone through both the luminosity bump and He-flash during their red giant branch (RGB) evolution. The stars’ large Li abundance and evolutionary phase suggest that Li enrichment occurred very recently, probably at the tip of the RGB either during He-flash, an immediate preceding event on the RGB, or by some kind of external event such as merger of an RGB star with white dwarf. The findings will provide critical constraints to theoretical models for understanding of Li enhancement origin in RGB stars.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:2041-8205-858-2-AAC16F
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/24751]
专题	中国科学院国家天文台
作者单位	1.Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China; bharat@bao.ac.cn 2.Indian Institute of Astrophysics, Koramangala II Block, Bangalore 560034, India 3.School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
推荐引用方式 GB/T 7714	Kumar,Yerra Bharat,Singh,Raghubar,Reddy,B. Eswar,et al. Two New Super Li-rich Core He-burning Giants: A New Twist to the Long Tale of Li Enhancement in K Giants[J]. The Astrophysical Journal Letters,2018,858(2).
APA	Kumar,Yerra Bharat,Singh,Raghubar,Reddy,B. Eswar,&Zhao,Gang.(2018).Two New Super Li-rich Core He-burning Giants: A New Twist to the Long Tale of Li Enhancement in K Giants.The Astrophysical Journal Letters,858(2).
MLA	Kumar,Yerra Bharat,et al."Two New Super Li-rich Core He-burning Giants: A New Twist to the Long Tale of Li Enhancement in K Giants".The Astrophysical Journal Letters 858.2(2018).