J/ApJ/733/124ivo://CDS.VizieR/J/ApJ/733/124doi:10.26093/cds/vizier.17330124CDSShappee B.J.Stanek K.Z.2017-06-30T05:48:50Z2012-12-12T12:43:44ZCDS support team

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

cds-question@unistra.frhst-photometryvariable-starsgalaxiesstellar-distanceWe accurately determine a new Cepheid distance to M101 (NGC 5457) using archival Hubble Space Telescope (HST)/Advanced Camera for Surveys V and I time series photometry of two fields within the galaxy. We make a slight modification to the ISIS image subtraction package to obtain optimal differential light curves from HST data. We discovered 827 Cepheids with periods between 3 and 80 days, the largest extragalactic sample of Cepheids observed with HST by a factor of two. With this large Cepheid sample, we find that the relative distance of M101 from the Large Magellanic Cloud is {Delta}{mu}_LMC_=10.63+/-0.04 (random) +/-0.06 (systematic) mag. If we use the geometrically determined maser distance to NGC 4258 as our distance anchor, the distance modulus of M101 is {mu}_0_=29.04+/-0.05 (random) +/-0.18 (systematic) mag or D=6.4+/-0.2 (random) +/-0.5 (systematic) Mpc. The uncertainty is dominated by the maser distance estimate (+/-0.15mag), which should improve over the next few years.2011ApJ...733..124Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/733/124CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/ApJ/715/277 : Insights into the Cepheid distance scale (Bono+, 2010)J/other/A+ARV/15.289 : Distances of local galaxies (Tammann+, 2008)J/ApJ/508/491 : M101 Cepheids (Stetson+, 1998)J/ApJ/463/26 : VI photometry of 29 Cepheids in M101. (Kelson+ 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/733/124https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/733/124http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/733/124https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/733/124https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/733/124http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/733/124GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/733/124/cepheids (Cepheid variables data })https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/733/124/cepheids?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/733/124/cepheids?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/733/124/cepheids?GETtext/xml+votable180.050000true210.8701908354.34667250.005555555555555556Cone search capability for table J/ApJ/733/124/table2 (Secondary standards)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/733/124/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/733/124/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/733/124/table2?GETtext/xml+votable180.050000true210.8685202854.354186940.005555555555555556Cone search capability for table J/ApJ/733/124/table4 (Rejected Cepheid Candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/733/124/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/733/124/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/733/124/table4?GETtext/xml+votable180.050000true210.8607013954.354151390.0055555555555555566/114342.0401237512456292e-19 4.2441532724171825e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/733/124?format=asciiOpticaldefaultJ/ApJ/733/124/cepheidsCepheid variables data }recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDCepheid identification (F[12]-NNNNNN)meta.id;meta.maincharPerPerioddtime.perioddoublee_PerUncertainty in Perdstat.errordoubleRAJ2000Right Ascension in decimal degrees (J2000) (1)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000) (1)degpos.eq.dec;meta.mainXpixX pixel locationpixpos.cartesian.xfloatYpixY pixel locationpixpos.cartesian.yfloatVmagMean HST V band magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatImagMean HST I band magnitudemagphot.mag;em.opt.Ifloate_ImagUncertainty Imagmagstat.error;phot.mag;em.opt.IfloatVampSemi-amplitude of V bandmagsrc.var.amplitudefloatIampSemi-amplitude of I bandmagsrc.var.amplitudefloatVarWelch-Stetson variability index value I_V_ (G1)src.var.indexfloatS98Cross-match wih the cepheids from Stetson et al., 1998, Cat. J/ApJ/508/491 within 1.5"meta.ref.urlintnullableF-TestF-Test ratio of reduced {chi}^2^stat.fit.goodnessfloatDMRelative distance modulusmagphot.mag.distModfloate_DMUncertainty in DMmmagstat.errorintE(V-I)E(V-I) color excessmagphot.color.excessfloate_E(V-I)Uncertainty in E(V-I)mmagstat.errorintE(B-V)E(B-V) color excessmagphot.color.excessfloate_E(B-V)Uncertainty in E(B-V)mmagstat.errorintrhoDeprojected galactoradius as fraction of isophotal radiuspos.distancefloat[O/H]Oxygen abundance at location (12+log[O/H])phys.abundfloatSimbadSimbad column added by the CDSmeta.refcharJ/ApJ/733/124/table2Secondary standardsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDCepheid identification (F[12]-NNNNN)meta.id;meta.maincharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainXpixX pixel locationpixpos.cartesian.xfloatYpixY pixel locationpixpos.cartesian.yfloatVmagMean HST V band magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatImagMean HST I band magnitudemagphot.mag;em.opt.Ifloate_ImagUncertainty Imagmagstat.error;phot.mag;em.opt.IfloatVarWelch-Stetson (1993AJ....105.1813W) variability index value I_V_ (G1)src.var.indexfloatJ/ApJ/733/124/table4Rejected Cepheid CandidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDCepheid identification (F[12]-NNNNNN)meta.id;meta.maincharPerPerioddtime.perioddoublee_PerUncertainty in Perdstat.errordoubleRAJ2000Right Ascension in decimal degrees (J2000) (1)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000) (1)degpos.eq.dec;meta.mainXpixX pixel locationpixpos.cartesian.xfloatYpixY pixel locationpixpos.cartesian.yfloatVmagMean HST V band magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatImagMean HST I band magnitudemagphot.mag;em.opt.Ifloate_ImagUncertainty Imagmagstat.error;phot.mag;em.opt.IfloatVampSemi-amplitude of V bandmagsrc.var.amplitudefloatIampSemi-amplitude of I bandmagsrc.var.amplitudefloatVarWelch-Stetson variability index value I_V_ (G1)src.var.indexfloatRej[A-F] Reason for rejection (for table 4 only) (2)meta.codechar