Super lithium-rich K giant with low C-12 to C-13 ratio

doi:10.1051/0004-6361/201730389

CORC > 国家天文台 > 中国科学院国家天文台

	Super lithium-rich K giant with low C-12 to C-13 ratio
	Zhou, Y. T.3,4; Shi, J. R.3,4; Yan, H. L.3; Gao, Q.3; Zhang, J. B.3,4; Zhao, G.3,4; Pan, K.1,2,3; Kumar, Y. B.3
刊名	ASTRONOMY & ASTROPHYSICS
	2018-07-17
卷号	615 页码:7
关键词	stars: late-type stars: individual: TYC 3251-581-1 stars: abundances stars: chemically peculiar
ISSN号	1432-0746
DOI	10.1051/0004-6361/201730389
英文摘要	Context. 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 Telescope (LAMOST) survey has obtained over six million spectra in the past five years, and thus provides a great opportunity to search these rare objects and to more clearly understand the mechanisms of Li enhancement. Aims. The aim of this work is to accurately measure the Li abundance and investigate the possible mechanisms of Li enrichment for a newly found super Li-rich giant, TYC 3251-581-1, located near the luminosity function bump with a low carbon isotopic ratio. Methods. Based on the high-resolution spectrum we obtained the stellar parameters (T-eff, log g, [Fe/H]), and determined the elemental abundances of Li, C, N, alpha, Fe-peak, r-process, s-process elements, and the projected rotational velocity. For a better understanding of the effect of mixing processes, we also derived the C-12 to C-13 ratio, and constrained the evolutionary status of TYC 3251-581-1 based on the BaSTI stellar isochrones. Results. The super Li-rich giant TYC 3251-581-1 has A(Li) = 3.51, the average abundance of two lithium lines at lambda = 6708 angstrom and 6104 angstrom based on the non-local thermodynamic equilibrium analysis. The atmospheric parameters show that our target locates on the luminosity function bump. The low carbon isotopic ratio (C-12/C-13 = 9.0), a slow rotational velocity v sin i = 2.2 km s(-1), and no sign of IR excess suggest that additional mixing after first dredge up (FDU) should occur to bring internal synthesized Li to the surface. The low carbon ([C/Fe] similar to 0.34) and enhanced nitrogen ([N/Fe] 0.33) are also consistent with the sign of mixing. Conclusions. Given the evolutionary stage of TYC 3251-581-1 with the relatively low C-12/C-13, the internal production which replenishes Li in the outer layer is the most likely origin of Li enhancement for this star.
资助项目	National Key Basic Research Programme of China[2014CB845700] ; National Natural Science Foundation of China[11603037] ; National Natural Science Foundation of China[11473033] ; Astronomical Big Data Joint Research Center ; Mt. Cuba Astronomical Foundation Grant ; Center for Astronomical Megascience, CAS ; National Development and Reform Commission ; National Aeronautics and Space Administration ; ESO Telescopes at the La Silla Paranal Observatory[188.B-3002]
WOS关键词	MASS RED GIANTS ; STELLAR EVOLUTION ; MAIN-SEQUENCE ; THICK DISC ; STARS ; ABUNDANCES ; ENGULFMENT ; BRANCH ; ATMOSPHERES ; COMPANIONS
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	EDP SCIENCES S A
WOS记录号	WOS:000439002800006
资助机构	National Key Basic Research Programme of China ; National Key Basic Research Programme of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Astronomical Big Data Joint Research Center ; Astronomical Big Data Joint Research Center ; Mt. Cuba Astronomical Foundation Grant ; Mt. Cuba Astronomical Foundation Grant ; Center for Astronomical Megascience, CAS ; Center for Astronomical Megascience, CAS ; National Development and Reform Commission ; National Development and Reform Commission ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; ESO Telescopes at the La Silla Paranal Observatory ; ESO Telescopes at the La Silla Paranal Observatory ; National Key Basic Research Programme of China ; National Key Basic Research Programme of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Astronomical Big Data Joint Research Center ; Astronomical Big Data Joint Research Center ; Mt. Cuba Astronomical Foundation Grant ; Mt. Cuba Astronomical Foundation Grant ; Center for Astronomical Megascience, CAS ; Center for Astronomical Megascience, CAS ; National Development and Reform Commission ; National Development and Reform Commission ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; ESO Telescopes at the La Silla Paranal Observatory ; ESO Telescopes at the La Silla Paranal Observatory ; National Key Basic Research Programme of China ; National Key Basic Research Programme of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Astronomical Big Data Joint Research Center ; Astronomical Big Data Joint Research Center ; Mt. Cuba Astronomical Foundation Grant ; Mt. Cuba Astronomical Foundation Grant ; Center for Astronomical Megascience, CAS ; Center for Astronomical Megascience, CAS ; National Development and Reform Commission ; National Development and Reform Commission ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; ESO Telescopes at the La Silla Paranal Observatory ; ESO Telescopes at the La Silla Paranal Observatory ; National Key Basic Research Programme of China ; National Key Basic Research Programme of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Astronomical Big Data Joint Research Center ; Astronomical Big Data Joint Research Center ; Mt. Cuba Astronomical Foundation Grant ; Mt. Cuba Astronomical Foundation Grant ; Center for Astronomical Megascience, CAS ; Center for Astronomical Megascience, CAS ; National Development and Reform Commission ; National Development and Reform Commission ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; ESO Telescopes at the La Silla Paranal Observatory ; ESO Telescopes at the La Silla Paranal Observatory
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/20798]
专题	中国科学院国家天文台
通讯作者	Zhou, Y. T.
作者单位	1.Apache Point Observ, POB 59, Sunspot, NM 88349 USA 2.New Mexico State Univ, POB 59, Sunspot, NM 88349 USA 3.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Zhou, Y. T.,Shi, J. R.,Yan, H. L.,et al. Super lithium-rich K giant with low C-12 to C-13 ratio[J]. ASTRONOMY & ASTROPHYSICS,2018,615:7.
APA	Zhou, Y. T..,Shi, J. R..,Yan, H. L..,Gao, Q..,Zhang, J. B..,...&Kumar, Y. B..(2018).Super lithium-rich K giant with low C-12 to C-13 ratio.ASTRONOMY & ASTROPHYSICS,615,7.
MLA	Zhou, Y. T.,et al."Super lithium-rich K giant with low C-12 to C-13 ratio".ASTRONOMY & ASTROPHYSICS 615(2018):7.