The PuZZling Li-Rich Red Giant Associated With NGC 6819

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dc.contributor.utaustinauthorShetrone, Matthewen_US
dc.creatorCarlberg, Joleen K.en_US
dc.creatorSmith, Verne V.en_US
dc.creatorCunha, Katiaen_US
dc.creatorMajewski, Steven R.en_US
dc.creatorMeszaros, Szabolcsen_US
dc.creatorShetrone, Matthewen_US
dc.creatorPrieto, Carlos Allendeen_US
dc.creatorBizyaev, Dmitryen_US
dc.creatorStassun, Keivan G.en_US
dc.creatorFleming, Scott W.en_US
dc.creatorZasowski, Gailen_US
dc.creatorHearty, Freden_US
dc.creatorNidever, David L.en_US
dc.creatorSchneider, Donald P.en_US
dc.creatorHoltzman, Jon A.en_US
dc.creatorFrinchaboy, Peter M.en_US
dc.date.accessioned2016-04-28T19:33:12Z
dc.date.available2016-04-28T19:33:12Z
dc.date.issued2015-03en
dc.description.abstractA Li-rich red giant (RG) star (2M19411367+4003382) recently discovered in the direction of NGC 6819 belongs to the rare subset of Li-rich stars that have not yet evolved to the luminosity bump, an evolutionary stage where models predict Li can be replenished. The currently favored model to explain Li enhancement in first-ascent RGs like 2M19411367+4003382 requires deep mixing into the stellar interior. Testing this model requires a measurement of C-12/C-13, which is possible to obtain from Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra. However, the Li-rich star also has abnormal asteroseismic properties that call into question its membership in the cluster, even though its radial velocity and location on color-magnitude diagrams are consistent with membership. To address these puzzles, we have measured a wide array of abundances in the Li-rich star and three comparison stars using spectra taken as part of the APOGEE survey to determine the degree of stellar mixing, address the question of membership, and measure the surface gravity. We confirm that the Li-rich star is a RG with the same overall chemistry as the other cluster giants. However, its log g is significantly lower, consistent with the asteroseismology results and suggestive of a very low mass if the star is indeed a cluster member. Regardless of the cluster membership, the C-12/C-13 and C/N ratios of the Li-rich star are consistent with standard first dredge-up, indicating that Li dilution has already occurred, and inconsistent with internal Li enrichment scenarios that require deep mixing.en_US
dc.description.departmentAstronomyen_US
dc.description.sponsorshipNational Science Foundation AST1109888en_US
dc.description.sponsorshipNSF AST-1358862, AST 1109718, AST 1312863en_US
dc.description.sponsorshipAlfred P. Sloan Foundationen_US
dc.description.sponsorshipNational Science Foundationen_US
dc.description.sponsorshipU.S. Department of Energy Office of Scienceen_US
dc.description.sponsorshipUniversity of Arizonaen_US
dc.description.sponsorshipBrazilian Participation Groupen_US
dc.description.sponsorshipBrookhaven National Laboratoryen_US
dc.description.sponsorshipCarnegie Mellon Universityen_US
dc.description.sponsorshipUniversity of Floridaen_US
dc.description.sponsorshipFrench Participation Groupen_US
dc.description.sponsorshipGerman Participation Groupen_US
dc.description.sponsorshipHarvard Universityen_US
dc.description.sponsorshipInstituto de Astrofisica de Canariasen_US
dc.description.sponsorshipMichigan State/NotreDame/JINA Participation Groupen_US
dc.description.sponsorshipJohns Hopkins Universityen_US
dc.description.sponsorshipLawrence Berkeley National Laboratoryen_US
dc.description.sponsorshipMax Planck Institute for Astrophysicsen_US
dc.description.sponsorshipMax Planck Institute for Extraterrestrial Physicsen_US
dc.description.sponsorshipNew Mexico State Universityen_US
dc.description.sponsorshipNew York Universityen_US
dc.description.sponsorshipOhio State Universityen_US
dc.description.sponsorshipPennsylvania State Universityen_US
dc.description.sponsorshipUniversity of Portsmouthen_US
dc.description.sponsorshipPrinceton Universityen_US
dc.description.sponsorshipSpanish Participation Groupen_US
dc.description.sponsorshipUniversity of Tokyoen_US
dc.description.sponsorshipUniversity of Utahen_US
dc.description.sponsorshipVanderbilt Universityen_US
dc.description.sponsorshipUniversity of Virginiaen_US
dc.description.sponsorshipUniversity of Washingtonen_US
dc.description.sponsorshipYale Universityen_US
dc.description.sponsorshipNational Aeronautics and Space Administrationen_US
dc.description.sponsorshipTwo Micron All Sky Surveyen_US
dc.description.sponsorshipUniversity of Massachusettsen_US
dc.description.sponsorshipInfrared Processing and Analysis Center/California Institute of Technologyen_US
dc.description.sponsorshipU.S. Government NAG W-2166en_US
dc.identifierdoi:10.15781/T2WC0X
dc.identifier.Filename2015_03_ngc6819.pdfen_US
dc.identifier.citationCarlberg, Joleen K., Verne V. Smith, Katia Cunha, Steven R. Majewski, Szabolcs M�sz�ros, Matthew Shetrone, Carlos Allende Prieto et al. "The Puzzling Li-Rich Red Giant Associated With Ngc 6819." The Astrophysical Journal, Vol. 802, No. 1 (Mar., 2015): 7.en_US
dc.identifier.doi10.1088/0004-637x/802/1/7en_US
dc.identifier.issn0004-637Xen_US
dc.identifier.urihttp://hdl.handle.net/2152/34719
dc.language.isoEnglishen_US
dc.relation.ispartofen_US
dc.relation.ispartofserialAstrophysical Journalen_US
dc.rightsAdministrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University.en_US
dc.rights.restrictionOpenen_US
dc.subjectopen clusters and associations: individual (ngc 6819)en_US
dc.subjectstars:en_US
dc.subjectabundancesen_US
dc.subjectstars: chemically peculiaren_US
dc.subjectstars: late-typeen_US
dc.subjectgalactic evolution experimenten_US
dc.subjectdigital sky surveyen_US
dc.subjectsdss-iii apogeeen_US
dc.subjectchemical-compositionen_US
dc.subjectopen clustersen_US
dc.subjectevolved starsen_US
dc.subjectradial-velocitiesen_US
dc.subjectclump starsen_US
dc.subjectabundancesen_US
dc.subjectkepleren_US
dc.subjectastronomy & astrophysicsen_US
dc.titleThe PuZZling Li-Rich Red Giant Associated With NGC 6819en_US
dc.typeArticleen_US

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