J/AJ/116/1775ivo://CDS.VizieR/J/AJ/116/1775doi:10.26093/cds/vizier.51161775CDSRey S.-C.Lee Y.-W.Byun Y.-I.Chun M.-S.2023-04-06T16:50:30Z1999-04-07T14:36:24ZCDS support team

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

cds-question@unistra.frglobular-star-clustersccd-photometryThe first large-format CCD color-magnitude diagram (CMD) in the B and V passbands is presented for the Galactic globular cluster M53 (NGC 5024). The observations consist of 40 pairs of B and V CCD frames with FWHM<1.2" in a pattern covering a 12'x13' region of M53. These frames were used to produce color-magnitude data for more than 20,000 stars from the tip of the red giant branch (RGB) to about 2 mag below the main-sequence turnoff (V~22). The CMD reveals a classic example of a metal-poor stellar system, with the horizontal branch (HB) predominantly blueward of the RR Lyrae instability strip and the relatively steep RGB. The blue HB of M53 does not show the blue tail phenomenon that is observed in M15. The relative age dating based on the color difference between the turnoff and the base of RGB reveals no significant age difference ({Delta}t<1Gyr) between M53 and M92. We have discovered 114 new blue straggler stars (BSSs) in the field of M53. The analysis of bright (V<19.39) BSSs clearly shows a bimodal radial distribution with a high frequency in the inner and outer regions but a distinct dip in the intermediate region. The distribution is similar to that found in M3, a globular cluster with a similar central density and concentration.1998AJ....116.1775Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/116/1775CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/97 : Updated 3rd Cat Variable Stars in Globular Clusters (Clement+ 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/116/1775https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/116/1775http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/116/1775https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/116/1775https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/116/1775http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/116/1775GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/116/1775/table2CCD photometry for M 53recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRLB/BSSSequential number (1)meta.id;meta.mainintxposX coordinate (2)pixpos.cartesian.x;instr.detdoubleHC91? Heasley & Christian (1991AJ....101..967H) numbermeta.idintnullableyposY coordinate (2)pixpos.cartesian.y;instr.detdoubleVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colour indexmagphot.color;em.opt.B;em.opt.VfloatJ/AJ/116/1775/table3Identified RR Lyrae variablesNameName (2)meta.id.part;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion designation (1)obs.fieldcharRLBRLB numbermeta.idintBand[BV] Bandinstr.bandpasscharmag1? Magnitude in Band at JD=2449807.872magphot.mag;em.IR.Kfloatnullablemag2? Magnitude in Band at JD=2449807.895magphot.mag;em.IR.Kfloatnullablemag3Magnitude in Band at JD=2449807.939magphot.mag;em.IR.Kfloatmag4Magnitude in Band at JD=2449807.965magphot.mag;em.IR.Kfloatmag5Magnitude in Band at JD=2449808.796magphot.mag;em.IR.Kfloatmag6Magnitude in Band at JD=2449808.881magphot.mag;em.IR.Kfloatmag7Magnitude in Band at JD=2449808.932magphot.mag;em.IR.Kfloatmag8Magnitude in Band at JD=2449809.007magphot.mag;em.IR.Kfloatmag9Magnitude in Band at JD=2449809.046magphot.mag;em.IR.Kfloatmag10? Magnitude in Band at JD=2449809.065magphot.mag;em.IR.Kfloatnullablemag11? Magnitude in Band at JD=2449809.113magphot.mag;em.IR.KfloatnullableJ/AJ/116/1775/table4New RR Lyrae candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion designation (1)obs.fieldcharNameName (2)meta.id.part;meta.maincharRLBRLB numbermeta.idintBand[BV] Bandinstr.bandpasscharmag1? Magnitude in Band at JD=2449807.872magphot.mag;em.IR.Kfloatnullablemag2? Magnitude in Band at JD=2449807.895magphot.mag;em.IR.Kfloatnullablemag3Magnitude in Band at JD=2449807.939magphot.mag;em.IR.Kfloatmag4Magnitude in Band at JD=2449807.965magphot.mag;em.IR.Kfloatmag5Magnitude in Band at JD=2449808.796magphot.mag;em.IR.Kfloatmag6Magnitude in Band at JD=2449808.881magphot.mag;em.IR.Kfloatmag7Magnitude in Band at JD=2449808.932magphot.mag;em.IR.Kfloatmag8Magnitude in Band at JD=2449809.007magphot.mag;em.IR.Kfloatmag9Magnitude in Band at JD=2449809.046magphot.mag;em.IR.Kfloatmag10? Magnitude in Band at JD=2449809.065magphot.mag;em.IR.Kfloatnullablemag11? Magnitude in Band at JD=2449809.113magphot.mag;em.IR.KfloatnullableJ/AJ/116/1775/table7M 53 blue straggler starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRLB/BSSSequential number (1)meta.id;meta.mainintxposX coordinate (2)pixpos.cartesian.x;instr.detdoubleyposY coordinate (2)pixpos.cartesian.y;instr.detdoubleVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colour indexmagphot.color;em.opt.B;em.opt.VfloatHC91? Heasley & Christian (1991AJ....101..967H) numbermeta.idintnullable