J/A+A/561/A87ivo://CDS.VizieR/J/A+A/561/A87doi:10.26093/cds/vizier.35610087CDSCarretta E.Bragaglia A.Gratton R.G.D'Orazi V.Lucatello S.,Sollima A.2014-06-29T08:49:44Z2014-01-07T07:12:21ZCDS support team

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

cds-question@unistra.frglobular-star-clustersinfrared-photometryvisible-astronomybroad-band-photometryradial-velocityMassive globular clusters (GCs) contain at least two generations of stars with slightly different ages and clearly distinct light elements abundances. The Na-O anticorrelation is the best studied chemical signature of multiple stellar generations. Low-mass clusters appear instead to be usually chemically homogeneous. We are investigating low-mass GCs to understand what is the lower mass limit where multiple populations can form, mainly using the Na and O abundance distribution. We used VLT/FLAMES spectra of giants in the low-mass, metal-poor GC Terzan 8, belonging to the Sagittarius dwarf galaxy, to determine abundances of Fe, O, Na, alpha-, Fe-peak, and neutron-capture elements in six stars observed with UVES and 14 observed with GIRAFFE. The average metallicity is [Fe/H]=-2.27+/-0.03 (rms=0.08), based on the six high-resolution UVES spectra. Only one star, observed with GIRAFFE, shows an enhanced abundance of Na and we tentatively assign it to the second generation. In this cluster, at variance with what happens in more massive GCs, the second generation seems to represent at most a small minority fraction. We discuss the implications of our findings, comparing Terzan 8 with the other Sgr dSph GCs, to GCs and field stars in the Large Magellanic Cloud, Fornax, and in other dwarfs galaxies.2014A&A...561A..87Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/561/A87CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/82/71 : Deep photometry of NGC 5694 and Terzan 8 (Ortolani+, 1990)J/AJ/136/614 : Arp 2 and Ter 8 red giants equivalent widths (Mottini+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/561/A87https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/561/A87http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/561/A87https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/561/A87https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/561/A87http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/561/A87GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/561/A87/table2 (ID, coordinates, magnitudes, RVs for stars in Terzan 8)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/561/A87/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/561/A87/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/561/A87/table2?GETtext/xml+votable180.050000true295.462375-34.06420560.0055555555555555566/47901 479032.367228618189496e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/561/A87?format=asciiOpticalInfrareddefaultJ/A+A/561/A87/table2ID, coordinates, magnitudes, RVs for stars in Terzan 8ID[11/3115] Star identification (from Montegriffo et al. 1998MNRAS.294..315M)meta.id;meta.mainintprimaryRAJ2000Right Ascension J2000pos.eq.ra;meta.mainDEJ2000Declination J2000pos.eq.dec;meta.mainVmagJohnson V magnitudemagphot.mag;em.opt.VfloatImagCousins I magnitudemagphot.mag;em.opt.IfloatKmag? 2MASS K magnitudemagphot.mag;em.IR.KfloatnullableHRV? Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatnullablee_HRV? Error on HRVkm/sstat.errorfloatnullableNoteAdditional information (1)meta.notechar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar