J/ApJ/652/1133ivo://CDS.VizieR/J/ApJ/652/1133doi:10.26093/cds/vizier.16521133CDSMacri L.M.Stanek K.Z.Bersier D.Greenhill L.J.Reid M.J.2017-06-13T11:09:15Z2008-11-18T14:15:06ZCDS support team

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

cds-question@unistra.frgalaxiesvariable-starsinfrared-photometryvisible-astronomybroad-band-photometryWe present initial results from a time series BVI survey of two fields in NGC 4258 using the HST ACS. This galaxy was selected because of its accurate maser-based distance, which is anticipated to have a total uncertainty of 3%. The goal of the HST observations is to provide an absolute calibration of the Cepheid distance scale and to measure its dependence on chemical abundance (the so-called metallicity effect). We carried out observations of two fields at different galactocentric distances with a mean abundance difference of 0.5dex. We discovered a total of 281 Cepheids with periods ranging from 4 to 45 days (the duration of our observing window).2006ApJ...652.1133Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/652/1133CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/652/1133https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/652/1133http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/652/1133https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/652/1133https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/652/1133http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/652/1133GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/652/1133/table2 (Secondary standards)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/652/1133/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/652/1133/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/652/1133/table2?GETtext/xml+votable180.050000true184.8007083347.181977780.005555555555555556Cone search capability for table J/ApJ/652/1133/cep (Cepheid variables: basic data and photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/652/1133/cep?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/652/1133/cep?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/652/1133/cep?GETtext/xml+votable180.050000true184.8361166747.175330560.005555555555555556Cone search capability for table J/ApJ/652/1133/table5 (Rejected Cepheid candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/652/1133/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/652/1133/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/652/1133/table5?GETtext/xml+votable180.050000true184.8380333347.191058330.0055555555555555566/10977 10979 10980 109822.367228618189496e-19 4.920466254354166e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/652/1133?format=asciiOpticalInfrareddefaultJ/ApJ/652/1133/table1Log of ObservationsNVisVisit Number (A-NN) (G1)meta.id;obscharObsObservation numbermeta.id;obscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_NVis[b] Note for For Visit No 7 (1)meta.notecharNorb[1/2] First or second orbit during the visitmeta.idintDateUT Datetime.epochnullableJD(B)B-band JD at midexposuredtime.epochdoubleJD(I)I-band JD at midexposuredtime.epochdoubleJD(V)V-band JD at midexposuredtime.epochdoubleJ/ApJ/652/1133/table2Secondary standardsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[MSB2006]Star identification, A-NNNNN (G1)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainXpixThe X pixel coordinatepixpos.cartesian.xfloatYpixThe Y pixel coordinatepixpos.cartesian.yfloatVmagThe V band magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmag in millimagnitudesmmagstat.error;phot.mag;em.opt.VintImagThe I band magnitudemagphot.mag;em.opt.Ifloate_ImagUncertainty in Imag in millimagnitudesmmagstat.error;phot.mag;em.opt.IintBmagThe B band magnitudemagphot.mag;em.opt.Bfloate_BmagUncertainty in Bmag in millimagnitudesmmagstat.error;phot.mag;em.opt.BintJ/ApJ/652/1133/cepCepheid variables: basic data and photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[MSB2006]Cepheid identification (G1)meta.id;meta.maincharprimaryPerPerioddtime.periodfloatRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainXpixThe X pixel coordinatepixpos.cartesian.xfloatYpixThe Y pixel coordinatepixpos.cartesian.yfloatVmagThe V band magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmag in millimagnitudesmmagstat.error;phot.mag;em.opt.VintImag? The I band magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag? Uncertainty in Imag in millimagnitudesmmagstat.error;phot.mag;em.opt.IintnullableBmag? The B band magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag? Uncertainty in Bmag in millimagnitudesmmagstat.error;phot.mag;em.opt.BintnullableVampThe V band semi-amplitudemmagsrc.var.amplitudeintIamp? The I band semi-amplitudemmagsrc.var.amplitudeintnullableBamp? The B band semi-amplitudemmagsrc.var.amplitudeintnullableLVModified Welch-Stetson V-band variability index valuemeta.code;meta.code.multipfloatLCLight curve, from the data in table7meta.ref.urlcharDM.VIExtinction corrected distance modulus determined from V and I data onlymagphot.mag.distModfloate_DM.VIUncertainty in muVI in millimagnitudesmmagstat.errorintE(V-I)The (V-I) color excessmagphot.color.excessfloate_E(V-I)Uncertainty in E(V-I) in millimagnitudesmmagstat.errorintDM.avgAverage extinction corrected distance modulus from B, V and I data (2)magphot.mag.distModfloate_DM.avgUncertainty in DM.avg in millimagnitudesmmagstat.errorintE(B-V)Average (B-V) color excess from B, V and I data (2)magphot.color.excessfloate_E(B-V)Uncertainty in E(B-V) in millimagnitudesmmagstat.errorintRGalDeprojected galactocentric radius in units of the isophotal radius (3)pos.distancefloatJ/ApJ/652/1133/table7Cepheid photometryPerPerioddtime.periodfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[MSB2006]Cepheid identification (G1)meta.id;meta.maincharObsObservation number (2)meta.id;obscharVmag? V band magnitude (3)magphot.mag;em.opt.Vfloatnullablee_Vmag? Uncertainty in Vmag in millimagnitudesmmagstat.error;phot.mag;em.opt.Vintnullableu_Vmag[*] Rejected measurement (4)meta.code.errorcharImag? I band magnitude (3)magphot.mag;em.opt.Ifloatnullablee_Imag? Uncertainty in Imag in millimagnitudesmmagstat.error;phot.mag;em.opt.Iintnullableu_Imag[*] Rejected measurement (4)meta.code.errorcharBmag? B band magnitude (3)magphot.mag;em.opt.Bfloatnullablee_Bmag? Uncertainty in Bmag in millimagnitudesmmagstat.error;phot.mag;em.opt.Bintnullableu_Bmag[*] Rejected measurement (4)meta.code.errorcharJ/ApJ/652/1133/table5Rejected Cepheid candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[MSB2006]Cepheid identification (G1)meta.id;meta.maincharPerPerioddtime.periodfloatRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainXpixThe X pixel coordinatepixpos.cartesian.xfloatYpixThe Y pixel coordinatepixpos.cartesian.yfloatVmagThe V band magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmag in millimagnitudesmmagstat.error;phot.mag;em.opt.VintImag? The I band magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag? Uncertainty in Imag in millimagnitudesmmagstat.error;phot.mag;em.opt.IintnullableBmag? The B band magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag? Uncertainty in Bmag in millimagnitudesmmagstat.error;phot.mag;em.opt.BintnullableVampThe V band semi-amplitudemmagsrc.var.amplitudeintIamp? The I band semi-amplitudemmagsrc.var.amplitudeintnullableBamp? The B band semi-amplitudemmagsrc.var.amplitudeintnullableLVModified Welch-Stetson V-band variability index valuemeta.code;meta.code.multipfloatRej[A-F] Reason for Cepheid candidate rejection (2)meta.codechar