J/ApJ/951/118ivo://CDS.VizieR/J/ApJ/951/118doi:10.26093/cds/vizier/ba-xq-3pCDSBreuval L.Riess A.G.Macri L.M.Li S.Yuan W.Casertano S.,Konchady T.Trahin B.Durbin M.J.Williams B.F.2026-02-10T20:05:42Z2025-09-24T12:57:52ZCDS support team

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

cds-question@unistra.frvariable-starshst-photometrystellar-distanceapparent-magnitudevisible-astronomyinfrared-astronomysurveysWe present a low-dispersion period-luminosity relation (PL) based on 154 Cepheids in Messier 33 (M33) with Hubble Space Telescope (HST) photometry from the PHATTER survey. Using high-quality ground-based light curves, we recover Cepheid phases and amplitudes for multi-epoch HST data and we perform template fitting to derive intensity-averaged mean magnitudes. HST observations in the SH0ES near-infrared Wesenheit system significantly reduce the effect of crowding relative to ground-based data, as seen in the final PL scatter of {sigma}=0.11mag. We adopt the absolute calibration of the PL based on HST observations in the Large Magellanic Cloud and a distance derived using late-type detached eclipsing binaries to obtain a distance modulus for M33 of {mu}=24.622+/-0.030mag (d=840+/-11kpc), a best-to-date precision of 1.3%. We find very good agreement with past Cepheid-based measurements. Several tip of the red giant branch estimates bracket our result while disagreeing with each other. Finally, we show that the flux contribution from star clusters hosting Cepheids in M33 does not impact the distance measurement and we find only ~3.7% of the sample is located in (or nearby) young clusters. M33 offers one of the best sites for the cross-calibration of many primary distance indicators. Thus, a precise independent geometric determination of its distance would provide a valuable new anchor to measure the Hubble constant.2023ApJ...951..118Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/951/118CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/121/870 : BVI photometry of Variables in M33 (Macri+, 2001)J/AJ/128/224 : VI photometry in M33 outer regions (Tiede+, 2004)J/ApJ/652/313 : BV phot. of a detached EB in M 33 (Bonanos+, 2006)J/MNRAS/371/1405 : Variables in M33 (Hartman+, 2006)J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)J/AJ/132/1361 : RR Lyrae variables in M33 (Sarajedini+, 2006)J/AJ/134/447 : Star cluster candidates in M 33 (Sarajedini+, 2007)J/ApJ/696/729 : Fluxes and abundances of PNe in M33 (Magrini+, 2009)J/ApJ/699/539 : Cepheids in SN-Ia host galaxies (Riess+, 2009)J/ApJS/193/26 : The M33 synoptic stellar survey. I. (Pellerin+, 2011)J/ApJ/758/11 : Bayesian distances to M31 satellites (Conn+, 2012)J/ApJ/759/146 : Spitzer/IRAC phot. for 37 Galactic Cepheids (Monson+, 2012)J/ApJ/745/156 : M31 Cepheids with HST/WFC3 (Riess+, 2012)J/A+A/576/A30 : NIR LC templates for classical Cepheids (Inno+, 2015)J/MNRAS/451/724 : PHAT. XIII. M31 Cepheid P-L relation (Wagner-Kaiser+, 2015)J/AJ/151/88 : LMC NIR Synoptic Survey. II. (Bhardwaj+, 2016)J/ApJ/864/59 : M31 PAndromeda Cepheids in four HST bands (Kodric+, 2018)J/AJ/156/112 : NIR Mira period-luminosity relations in M33 (Yuan+, 2018)J/ApJ/876/85 : HST observations for LMC Cepheids (Riess+, 2019)J/ApJ/904/13 : RVel for 10 giant eclipsing binaries (Graczyk+, 2020)J/ApJ/902/145 : Cosmicflows-4: Tully-Fisher distances (Kourkchi+, 2020)J/ApJ/902/26 : HST opt. & H-band obs. of Cepheids in NGC4151 (Yuan+, 2020)J/ApJ/913/38 : Compilation of Cepheids in the MW and MCs (Breuval+, 2021)J/ApJ/920/84 : HST photometry of 55 cepheids in M31 (Li+, 2021)J/ApJS/253/53 : PHATTER. I. 22 million stars in M33 (Williams+, 2021)J/ApJ/938/81 : PHATTER. IV. Star cluster catalog (Johnson+, 2022)J/ApJ/939/44 : CHAOS. VII. Large-scale abundances in M33 (Rogers+, 2022)J/A+A/658/A29 : LMC classical Cepheids Fe and O content (Romaniello+, 2022)J/AJ/165/137 : Light curve and observed properties in M33 (Ou+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/951/118https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/951/118http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/951/118https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/951/118https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/951/118http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/951/118GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/951/118/table9 (*Full HST M33 Cepheids used in this analysis and their mean magnitudes obtained from template fitting)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/951/118/table9?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/951/118/table9?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/951/118/table9?GETtext/xml+votable180.050000true23.3586230.555480.0055555555555555566/21551.1796835550914393e-19 2.706461185444514e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/951/118?format=asciiOpticalInfrareddefaultJ/ApJ/951/118/table9*Full HST M33 Cepheids used in this analysis and their mean magnitudes obtained from template fittingrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDCepheid identifier (HHMMSSss+DDMMSSs)meta.id;meta.maincharf_ID[*] *: a cluster Cepheids in Section 5meta.codecharRAJ2000[23.3/23.7] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[30.4/30.9] Declination (J2000)degpos.eq.dec;meta.mainlogP[0.53/1.9] Log periodlog(d)time.periodfloatF160Wmag[16.19/20.5] Apparent HST/WFC3 F160W band magnitudemagphot.mag;em.IR.Hfloate_F160Wmag[12/294] Uncertainty in F160Wmagmmagstat.error;phot.mag;em.IR.HintF475Wmag[19.16/22.7] Apparent HST F475W band magnitudemagphot.mag;em.opt.Bfloate_F475Wmag[4/634] Uncertainty in F475Wmagmmagstat.error;phot.mag;em.opt.BintF814Wmag[17.74/21.53] Apparent HST F814W band magnitudemagphot.mag;em.opt.Ifloate_F814Wmag[2/358] Uncertainty in F814Wmagmmagstat.error;phot.mag;em.opt.IintmWH[15.64/20.2] NIR HST/WFC3 Wesenheit index (1)magphot.mag;arith.diff;em.IR.NIRfloate_mWH[21/300] Uncertainty in mWHmmagstat.errorintdGC[0.43/5.43] Deprojected galactocentric distancekpcpos.distance;pos.galactocentricfloatDelCor[-0.005/0.008] Geometric correctionmagphot.mag;arith.difffloatSetSample identifier; (G)old or (S)ilvermeta.code;src.samplecharH06Display data from Hartman+ 2006, J/MNRAS/371/1405meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar