J/A+AS/127/167ivo://CDS.VizieR/J/A+AS/127/167CDSRichtler T.Grebel E.K.Subramaniam A.Sagar S.1998-02-04T08:54:31Z1998-02-04T09:52:13ZCDS support team

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

cds-question@unistra.frglobular-star-clustersccd-photometryWe present CCD photometry in V and I for the metal-rich globular cluster NGC 6528. A comparison with previous photometry reveals discrepancies of the order 0.1 to 0.2mag in V, emphasizing the need for independent photometry. As found previously, the giant branch (or the asymptotic giant branch, which cannot be distinguished) of the cluster extends to V-I=7. Population synthesis in V-I must take these red stars into account in order to understand integrated red colours of bulge populations. Currently available theoretical isochrones do not reproduce the shape of the RGB/AGB. The derivation of reliable values for reddening, distance and metallicity of NGC 6528 is hampered by uncertainties in the extrapolation to high metallicity, which dominate the absolute error rather than the photo metric uncertainty does. Together with other properties (old age derived from HST data, high radial velocity), this object is more likely a member of the bulge than of the disk population.1998A&AS..127..167Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/127/167CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/127/167https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/127/167http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/127/167https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/127/167https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/127/167http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/127/167GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+AS/127/167/table6Position and photometry of 24999 stars in a field of view of 5.7'x5.7'recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential numbermeta.id;meta.mainintXposX position (1)pixpos.cartesian.x;instr.detfloatyposY position (1)pixpos.cartesian.y;instr.detfloatVmagV magnitudemagphot.mag;em.opt.Vfloate_Vmagrms uncertainty on Vmagmagstat.errorfloatV-IV-I colour indexmagphot.color;em.opt.V;em.opt.Ifloate_V-Irms uncertainty on V-Imagstat.errorfloatChichi-value returned from DAOPHOTstat.fit.chi2float