J/AJ/109/269ivo://CDS.VizieR/J/AJ/109/269doi:10.26093/cds/vizier.51090269CDSSarajedini A.Milone A.A.E.2023-04-06T16:50:11Z1997-12-09T20:25:14ZCDS support team

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

cds-question@unistra.frglobular-star-clustersccd-photometryWe present (V,B-V), (V,V-I), and (V,B-I) color-magnitude diagrams for NGC 5053, which is the most metal-poor globular cluster known in the galaxy. The horizontal branch (HB) is predominantly blueward of the RR Lyrae instability strip and the slope of the red giant branch (RGB) is relatively steep, both characteristic of a metal-poor system. Monte- Carlo simulations show that both the RGB and HB are underpopulated relative to those of the metal-poor cluster M15, indicative of the relatively lower total luminosity of NGC 5053. Based on the mean magnitude of stars located at the red and blue edges of the instability strip, we find V(HB) = 16.65 +/- 0.03. At this magnitude, polynomial fits to the cluster RGBs in the two measured colors yield (B-V)_g = 0.71 +/- 0.016 and (V-I)_g = 0.93 +/- 0.016. Using the BVI two-color diagram in a differential manner with respect to M68 and M15 gives a reddening of E(B-V) = 0.06 +/- 0.02 for NGC 5053. We have utilized these quantities to extend the calibration of the simultaneous reddening and metallicity method [Sarajedini, AJ, 107, 618 (1994a)] to [Fe/H] = -2.4. Another feature of the color-magnitude diagram that is evident is the rich population of blue straggler stars (BSSs). We are able to recover 22 of 24 previously known BSSs, and we have added 3 more BSSs.1995AJ....109..269Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/109/269CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/109/269https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/109/269http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/109/269https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/109/269https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/109/269http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/109/269GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/109/269/table2 (NGC 5053 photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/109/269/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/109/269/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/109/269/table2?GETtext/xml+votable180.050000true199.166998917.75228170.0055555555555555566/27984 279863.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/109/269?format=asciiOpticaldefaultJ/AJ/109/269/table2NGC 5053 photometryStarStar numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXposX pixel positionpixpos.cartesian.xdoubleYposY pixel positionpixpos.cartesian.ydoubleVmagV magnitudemagphot.mag;em.opt.VfloatB-V[]? B-V colormagphot.color;em.opt.B;em.opt.VfloatnullableV-I[]? V-I colormagphot.color;em.opt.V;em.opt.Ifloatnullableo_B-VNumber of frame pairs on which each B-V measurement was mademeta.numberinto_V-INumber of frame pairs on which each V-I measurement was mademeta.numberint_RAPosition computed from a comparison with 2MASS (Cat. II/246) ({sigma}=0.09'') (right ascension part)degpos.eq.ra;meta.main_DEPosition computed from a comparison with 2MASS (Cat. II/246) ({sigma}=0.09'') (declination part)degpos.eq.dec;meta.main