The R-Process Alliance: 2MASS J09544277+5246414, the Most Actinide-enhanced R-II Star Known

doi:10.3847/2041-8213/aac722

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	The R-Process Alliance: 2MASS J09544277+5246414, the Most Actinide-enhanced R-II Star Known
	Holmbeck, Erika M.1,2; Beers, Timothy C.1,2; Roederer, Ian U.2,3; Placco, Vinicius M.1,2; Hansen, Terese T.4; Sakari, Charli M.5; Sneden, Christopher 6,7; Liu, Chao 8; Lee, Young Sun 9; Cowan, John J.10
刊名	ASTROPHYSICAL JOURNAL LETTERS
	2018-06-01
卷号	859 期号:2 页码:6
关键词	Galaxy: halo stars: abundances stars: atmospheres stars: individual (2MASS J09544277+5246414) stars: Population II
ISSN号	2041-8205
DOI	10.3847/2041-8213/aac722
英文摘要	We report the discovery of a new actinide-boost star, 2MASS. J09544277+5246414, originally identified as a very bright (V = 10.1), extremely metal-poor ([Fe/H] = -2.99) K giant in the LAMOST survey, and found to be highly r-process-enhanced (r-II; [Eu/Fe] = +1.28]), during the snapshot phase of the R-Process Alliance (RPA). Based on a high signal-to-noise ratio (S/N), high-resolution spectrum obtained with the Harlan J. Smith 2.7 m telescope, this star is the first confirmed actinide-boost star found by RPA efforts. With an enhancement of [Th/Eu] = +0.37, 2MASS. J09544277+ 5246414 is also the most actinide-enhanced r-II star yet discovered, and only the sixth metalpoor star with a measured uranium abundance ([U/Fe] = +1.40). Using the Th/U chronometer, we estimate an age of 13.0 +/- 4.7. Gyr for this star. The unambiguous actinide-boost signature of this extremely metal-poor star, combined with additional r-process-enhanced and actinide-boost stars identified by the RPA, will provide strong constraints on the nature and origin of the r-process at early times.
资助项目	Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation[PHY 14-30152] ; NSF[AST1616040] ; National Research Foundation of Korea - Ministry of Science and ICT[2017R1A5A1070354] ; National Research Foundation of Korea - Ministry of Science and ICT[NRF-2015R1C1A1A02036658] ; National Research Foundation of Korea - Ministry of Science and ICT[NRF-2018R1A2B6003961]
WOS关键词	NEUTRON-CAPTURE ; CS 31082-001 ; HALO STAR ; ABUNDANCE ; GALAXY ; EVOLUTION ; ELEMENTS ; PATTERN ; SEARCH ; FE/H
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000433932700001
资助机构	Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; NSF ; NSF ; National Research Foundation of Korea - Ministry of Science and ICT ; National Research Foundation of Korea - Ministry of Science and ICT ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; NSF ; NSF ; National Research Foundation of Korea - Ministry of Science and ICT ; National Research Foundation of Korea - Ministry of Science and ICT ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; NSF ; NSF ; National Research Foundation of Korea - Ministry of Science and ICT ; National Research Foundation of Korea - Ministry of Science and ICT ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation ; NSF ; NSF ; National Research Foundation of Korea - Ministry of Science and ICT ; National Research Foundation of Korea - Ministry of Science and ICT
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/21708]
专题	中国科学院国家天文台
通讯作者	Holmbeck, Erika M.
作者单位	1.Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA 2.JINA Ctr Evolut Elements, E Lansing, MI 48824 USA 3.Univ Michigan, Dept Astron, 1085 South Univ Ave, Ann Arbor, MI 48109 USA 4.Observ Carnegie Inst Washington, Pasadena, CA 91101 USA 5.Univ Washington, Dept Astron, Seattle, WA 98195 USA 6.Univ Texas Austin, Dept Astron, Austin, TX 78712 USA 7.Univ Texas Austin, McDonald Observ, Austin, TX 78712 USA 8.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 9.Chungnam Natl Univ, Dept Astron & Space Sci, Daejeon 34134, South Korea 10.Univ Oklahoma, HLD Dept Phys & Astron, Norman, OK 73019 USA
推荐引用方式 GB/T 7714	Holmbeck, Erika M.,Beers, Timothy C.,Roederer, Ian U.,et al. The R-Process Alliance: 2MASS J09544277+5246414, the Most Actinide-enhanced R-II Star Known[J]. ASTROPHYSICAL JOURNAL LETTERS,2018,859(2):6.
APA	Holmbeck, Erika M..,Beers, Timothy C..,Roederer, Ian U..,Placco, Vinicius M..,Hansen, Terese T..,...&Frebel, Anna.(2018).The R-Process Alliance: 2MASS J09544277+5246414, the Most Actinide-enhanced R-II Star Known.ASTROPHYSICAL JOURNAL LETTERS,859(2),6.
MLA	Holmbeck, Erika M.,et al."The R-Process Alliance: 2MASS J09544277+5246414, the Most Actinide-enhanced R-II Star Known".ASTROPHYSICAL JOURNAL LETTERS 859.2(2018):6.