J/ApJ/743/176ivo://CDS.VizieR/J/ApJ/743/176doi:10.26093/cds/vizier.17430176CDSGerke J.R.Kochanek C.S.Prieto J.L.Stanek K.Z.Macri L.M.2013-08-07T08:00:03Z2013-07-23T09:48:35ZCDS support team

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

cds-question@unistra.frgalaxieshst-photometryvariable-starsWe identify and phase a sample of 107 Cepheids with 10days<P<100days in M81 (NGC 3031) using the Large Binocular Telescope and calibrate their B, V, and I mean magnitudes with archival Hubble Space Telescope (HST) data. The use of a ground-based telescope to identify and phase the Cepheids and HST only for the final calibration reduces the demand on this highly oversubscribed spacecraft by nearly an order of magnitude and yields period-luminosity (PL) relations with dispersions comparable to the best LMC samples. We fit the sample using the OGLE-II LMC PL relations and are unable to find a self-consistent distance for different band combinations or radial locations within M81. We find a distance modulus for M81, relative to the LMC, of {mu}M_81_-{mu}_LMC_=9.39+/-0.14mag, including uncertainties due to the metallicity corrections. This corresponds to a distance to M81 of 3.6+/-0.2Mpc, assuming an LMC distance modulus of 18.41mag.2011ApJ...743..176Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/743/176CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/ApJ/734/L22 : ACS Nearby Galaxy Survey Treasury (Williams+, 2011)J/ApJ/730/119 : HST/WFC3 observations of Cepheids in SN Ia (Riess+, 2011)J/ApJ/715/277 : Insights into the Cepheid distance scale (Bono+, 2010)J/A+A/504/959 : Amplitudes of single-mode Cepheids (Klagyivik+, 2009)J/ApJ/699/539 : Cepheids in SN-Ia host galaxies (Riess+, 2009)J/AcA/58/163 : VI light curves of LMC classical Cepheids (Soszynski+, 2008)J/other/A+ARV/15.289 : Distances of local galaxies (Tammann+, 2008)J/A+A/411/361 : VI photometry of extra-galactic Cepheids (Kanbur+, 2003)http://www.nearbygalaxies.org/ : ANGST (ACS Nearby Galaxy Survey Treasury)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/743/176https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/743/176http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/743/176https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/743/176https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/743/176http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/743/176GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/743/176/table1 (Cepheid parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/743/176/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/743/176/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/743/176/table1?GETtext/xml+votable180.050000true149.062291769.02805560.0055555555555555566/76062.0401237512456292e-19 3.9057996558789745e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/743/176?format=asciiOpticaldefaultJ/ApJ/743/176/table1Cepheid parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintM81CCepheid identification (HHMMSS.ss+DDMMSS.s; J2000) (1)meta.id;meta.maincharf_M81CRemoved Cepheid from final sample (3)meta.codecharPer[10/99] Perioddtime.periodfloatBmagCalibrated phase-averaged mean B-band magnitudemagphot.mag;em.opt.Bfloate_BmagBmag uncertaintymagstat.error;phot.mag;em.opt.BfloatVmagCalibrated phase-averaged mean V-band magnitudemagphot.mag;em.opt.Rfloate_VmagVmag uncertaintymagstat.error;phot.mag;em.opt.VfloatImagCalibrated phase-averaged mean I-band magnitudemagphot.mag;em.opt.Ifloate_ImagImag uncertaintymagstat.error;phot.mag;em.opt.IfloatF94ID from Freedman et al. (2)meta.id.crosschar_RAPositions from Cepheid names (right ascension part)degpos.eq.ra;meta.main_DEPositions from Cepheid names (declination part)degpos.eq.dec;meta.main