J/ApJ/897/78ivo://CDS.VizieR/J/ApJ/897/78doi:10.26093/cds/vizier.18970078CDSPlacco V.M.Santucci R.M.Yuan Z.Mardini M.K.Holmbeck E.M.Wang X.,Surman R.Hansen T.T.Roederer I.U.Beers T.C.Choplin A.Ji A.P.,Ezzeddine R.Frebel A.Sakari C.M.Whitten D.D.Zepeda J.2022-03-15T04:12:46Z2021-10-12T07:38:40ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frchemically-peculiar-starschemical-abundancesvisible-astronomyspectroscopyWe report on the spectroscopic analysis of RAVE-J183013.5-455510, an extremely metal-poor star, highly enhanced in CNO, and with discernible contributions from the rapid neutron-capture process. There is no evidence of binarity for this object. At [Fe/H]=-3.57, this star has one of the lowest metallicities currently observed, with 18 measured abundances of neutron-capture elements. The presence of Ba, La, and Ce abundances above the solar system r-process predictions suggests that there must have been a non-standard source of r-process elements operating at such low metallicities. One plausible explanation is that this enhancement originates from material ejected at unusually high velocities in a neutron star merger event. We also explore the possibility that the neutron-capture elements were produced during the evolution and explosion of a rotating massive star. In addition, based on comparisons with yields from zero-metallicity faint supernova, we speculate that RAVE-J1830-4555 was formed from a gas cloud pre-enriched by both progenitor types. From analysis based on Gaia DR2 measurements, we show that this star has orbital properties similar to the Galactic metal-weak thick-disk stellar population.2020ApJ...897...78Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/897/78CatalogResearchIsServedByTAP VizieR generic servicerelated-toIII/279 : RAVE 5th data release (Kunder+, 2017)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)I/349 : StarHorse, Gaia DR2 photo-astrometric distances (Anders+, 2019)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)J/ApJ/724/975 : Heavy elements abundances of metal-poor stars (Roederer+, 2010)J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/ApJ/773/33 : Chemical analysis of metal-poor subgiant BD+44 493 (Ito+, 2013)J/ApJ/794/58 : Metal-poor stars in the thick disk of the Galaxy (Beers+, 2014)J/ApJ/781/40 : Metal-poor stars from HES survey. II. Spectro. (Placco+, 2014)J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)J/AJ/147/136 : Stars very low metal abundance. VI. Abundances (Roederer+,2014)J/ApJ/807/171 : SkyMapper Survey metal-poor star spectroscopy (Jacobson+, 2015)J/ApJ/812/109 : HST & Keck spectroscopy of bright CEMP-s stars (Placco+, 2015)J/ApJ/824/L19 : Carbon-enhanced metal-poor star BD+44493 EWs (Roederer+, 2016)J/ApJ/833/20 : Carbon-enhanced metal-poor (CEMP) star abundances (Yoon+, 2016)J/ApJ/835/81 : Bright metal-poor stars from HES Survey. II. (Beers+, 2017)J/ApJ/838/44 : Abundances of the brightest member of Tuc III (Hansen+, 2017)J/ApJ/864/43 : Abundances of 3 bright extremely metal-poor giants (Cain+,2018)J/A+A/618/A133 : Non standard s-process massive rotating stars (Choplin+, 2018)J/ApJ/862/174 : Spectroscopy obs. of RAVE J094921.8-161722 (Gull+, 2018)J/ApJ/858/92 : RPA Southern Pilot Search of 107 Stars (Hansen+, 2018)J/ApJS/237/13 : Models and yields of 13-120M{sun} massive stars (Limongi+,2018)J/ApJ/852/99 : Abundances 3 metal-poor stars in Horologium I (Nagasawa+, 2018)J/AJ/155/256 : Spectroscopic validation RAVE metal-poor stars (Placco+, 2018)J/AJ/156/179 : Highly r-process-enhanced field stars kine. (Roederer+, 2018)J/ApJ/865/129 : Abundance analysis of HD 222925 (Roederer+, 2018)J/ApJ/868/110 : R-Process Alliance: 1st release in Galactic halo (Sakari+,2018)J/A+A/623/A128 : Galactic halo CEMP stars abundances&kinematics (Hansen+, 2019)J/ApJ/882/40 : Lanthanide fraction distribution of metal-poor stars (Ji+,2019)J/ApJ/875/89 : Metal-poor stars with APF. I. LAMOST CEMP stars (Mardini+,2019)J/ApJ/882/27 : Metal-poor stars with APF obs II. MW halo stars (Mardini+,2019)J/ApJ/882/177 : Abundances of 4 member stars of Tucana III (Marshall+, 2019)J/ApJ/870/122 : Spectroscopy of low-metallicity star candidates (Placco+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/897/78https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/897/78http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/897/78https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/897/78https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/897/78http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/897/78GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/897/78/table3Equivalent-width measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpeciesphys.atmol.ionStagecharlambda[3360/8335] Wavelength, Angstroms0.1nmem.wldoubleExPot[0/4.34]? Excitation potentialeVphys.atmol.excitationfloatnullableloggf[-9.82/0.76]? Log oscillator strengthphys.atmol.oscStrengthfloatnullablef_EWFlag on EW (1)meta.codecharEW[6.78/162]? Equivalent width1e-13mspect.line.eqWidthfloatnullablel_logeps(x)Limit flag on logepsmeta.code.errorcharlogeps(x)[-2.85/7.36] Log number abundance of Ionlog(Sun)meta.id;meta.mainfloat