J/A+A/507/803ivo://CDS.VizieR/J/A+A/507/803doi:10.26093/cds/vizier.35070803CDSDekany I.Kovacs G.2017-11-29T11:48:27Z2010-01-09T18:18:15ZCDS support team

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

cds-question@unistra.frglobular-star-clustersvariable-starsinfrared-photometryvisible-astronomyphotometryWe study the variable star content of the globular cluster M53 to compute the physical parameters of the constituting stars and the distance of the cluster. Covering two adjacent seasons in 2007 and 2008, new photometric data are gathered for 3048 objects in the field of M53. By using the OIS (optimal image subtraction) method and subsequently TFA (trend filtering algorithm), we search for variables in the full sample by using discrete Fourier transformation and box-fitting least squares method. We select variables based on the statistics related to these methods combined with visual inspection. We identified 12 new variables (2 RR Lyrae stars, 7 short periodic stars - 3 of them are SX Phe stars - and 3 long-period variables). No eclipsing binaries were found in the present sample. Except for the 3 (hitherto unknown) Blazhko RR Lyrae (two RRab and an RRc) stars, no multiperiodic variables were found. We showed that after proper period shift, the PLC (period-luminosity-color) relation for the first overtone RR Lyrae sample tightly follows the one spanned by the fundamental stars. Furthermore, the slope is in agreement with that derived from other clusters. Based on the earlier Baade-Wesselink calibration of the PLC relations, the derived reddening-free distance modulus of M53 is 16.31+/-0.04mag, corresponding to a distance modulus of 18.5mag for the Large Magellanic Cloud. From the Fourier parameters of the RRab stars we obtained an average iron abundance of -1.58+/-0.03 (error of the mean). This is ~0.5dex higher than the overall abundance of the giants as given in the literature and derived in this paper from the three-color photometry of giants. We suspect that the source of this discrepancy (observable also in other, low-metallicity clusters) is the lack of a sufficient number of low-metallicity objects in the calibrating sample of the Fourier method.2009A&A...507..803Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/507/803CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/109/269 : Photometry of NGC 5053 (Sarajedini+ 1995)J/PAZh/23/454 : Identification and coordinates in M 53 (Evstigneeva+, 1997)J/AJ/116/1775 : BV photometry of M53 (Rey+, 1998)J/A+A/358/547 : M53 variable stars V light curves (Kopacki, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/507/803https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/507/803http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/507/803https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/507/803https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/507/803http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/507/803GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/507/803/stars (Properties of the RR Lyrae stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/507/803/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/507/803/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/507/803/stars?GETtext/xml+votable180.050000true198.23458318.12050.0055555555555555566/27975 27981 279923.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/507/803?format=asciiOpticalInfrareddefaultJ/A+A/507/803/starsProperties of the RR Lyrae starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification name, VNNmeta.id;meta.maincharprimaryn_ID[*] * for new detectionsmeta.notecharTypeVariability type (1)meta.code;src.varcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.maindRadial distance (2)arcsecphys.angSizefloatPer? Perioddtime.perioddoublenullablee_Per? rms uncertainty on Per1e-07dstat.errorintnullableSNRSignal-to-noise ratio (3)stat.snrfloatl_Vmag[~] Limit flag on Vmagmeta.code.errorcharVmag? Average Johnson V magnitude (4)magphot.mag;em.opt.VfloatnullableV-Ic? Average Johnson-Cousins V-I colour index (4) (5)magphot.color;em.opt.V;em.opt.IfloatnullableFreq? Frequencyd**-1em.freqdoublenullableFSimbad column added by the CDSmeta.ref.urlcharLCDisplay V, I relative fluxes curvesmeta.ref.urlcharJ/A+A/507/803/rrlvcoeFourier decompositions of cluster RR Lyrae stars with magnitude-transformed light curves in V colorNNumber of data pointsmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identification in CVSGC, VNN, Cl* NGC 5024 GOR VNN in Simbadmeta.id;meta.maincharTypeRR Lyrae type (RR0 or RR1)meta.notecharPerPerioddtime.perioddoublet0Epoch of Fourier decomposition (1)time.epochdoubleA0Zero-frequency constant (magnitude average) (1)magphot.mag;stat.meanfloatsigmaResidual standard deviationmagstat.stdev;phot.magfloatATotal amplitudemagsrc.var.amplitudefloatMOrder of the Fourier decompositionstat.fit.paramintA1A1 Fourier amplitude (1)magsrc.var.amplitudefloatphi1{phi}1 Fourier phase (1)radstat.FourierfloatA2A2 Fourier amplitude (1)magsrc.var.amplitudefloatphi2{phi}2 Fourier phase (1)radstat.FourierfloatA3A3 Fourier amplitude (1)magsrc.var.amplitudefloatphi3{phi}3 Fourier phase (1)radstat.FourierfloatA4A4 Fourier amplitude (1)magsrc.var.amplitudefloatphi4{phi}4 Fourier phase (1)radstat.FourierfloatA5A5 Fourier amplitude (1)magsrc.var.amplitudefloatphi5{phi}5 Fourier phase (1)radstat.FourierfloatA6A6 Fourier amplitude (1)magsrc.var.amplitudefloatphi6{phi}6 Fourier phase (1)radstat.FourierfloatA7A7 Fourier amplitude (1)magsrc.var.amplitudefloatphi7{phi}7 Fourier phase (1)radstat.FourierfloatA8A8 Fourier amplitude (1)magsrc.var.amplitudefloatphi8{phi}8 Fourier phase (1)radstat.FourierfloatA9A9 Fourier amplitude (1)magsrc.var.amplitudefloatphi9{phi}9 Fourier phase (1)radstat.FourierfloatA10A10 Fourier amplitude (1)magsrc.var.amplitudefloatphi10{phi}10 Fourier phase (1)radstat.Fourierfloat