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dc.contributor.authorFrebel, Anna
dc.date.accessioned2020-04-17T19:15:58Z
dc.date.available2020-04-17T19:15:58Z
dc.date.issued2018-06
dc.date.submitted2018-04
dc.identifier.issn2041-8213
dc.identifier.issn2041-8205
dc.identifier.urihttps://hdl.handle.net/1721.1/124736
dc.description.abstractWe 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 metal-poor 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. ©2018en_US
dc.publisherAmerican Astronomical Societyen_US
dc.relation.isversionof10.3847/2041-8213/AAC722en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourceThe Astrophysical Journal Lettersen_US
dc.titleThe R-Process Alliance: 2MASS J09544277+5246414, the most actinide-enhanced R-II star knownen_US
dc.typeArticleen_US
dc.identifier.citationHolmbeck, Erika M., et al., "The R-Process Alliance: 2MASS J09544277+5246414, the most actinide-enhanced R-II star known." Astrophysical journal. Letters 859, 2 (June 2018): letter 24 doi 10.3847/2041-8213/AAC722 ©2018 Author(s)en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Physicsen_US
dc.contributor.departmentMIT Kavli Institute for Astrophysics and Space Researchen_US
dc.relation.journalAstrophysical journal. Lettersen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dc.date.updated2019-03-22T15:41:40Z
dspace.orderedauthorsHolmbeck, Erika M.; Beers, Timothy C.; Roederer, Ian U.; Placco, Vinicius M.; Hansen, Terese T.; Sakari, Charli M.; Sneden, Christopher; Liu, Chao; Lee, Young Sun; Cowan, John J.; Frebel, Annaen_US
dspace.embargo.termsNen_US
dspace.date.submission2019-04-04T10:43:14Z
mit.journal.volume859en_US
mit.journal.issue2en_US
mit.licensePUBLISHER_POLICYen_US


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