J/A+A/619/A8ivo://CDS.VizieR/J/A+A/619/A8doi:10.26093/cds/vizier.36190008CDSGroenewegen M.A.T.2018-12-03T15:08:28Z2018-11-06T07:35:35ZCDS support team

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

cds-question@unistra.frstellar-distancevisible-astronomytrigonometric-parallaxWe use parallax data from the Gaia second data release (GDR2), combined with parallax data based on HIPPARCOS and HST data, to derive the period-luminosity-metallicity (PLZ) relation for Galactic classical cepheids (CCs) in the V, K, and Wesenheit WVK bands. An initial sample of 452 CCs are extracted from the literature with spectroscopically derived iron abundances. Reddening values, classifications, pulsation periods, and mean V- and K-band magnitudes are taken from the literature. Based on nine CCs with a goodness-of-fit (GOF) statistic smaller than 8 and with an accurate non-Gaia parallax ({sigma}_{pi}_ comparable to that in GDR2), a parallax zero-point offset of -0.049+/-0.018mas is derived. Selecting a GOF statistic smaller than 8 removes about 40% of the sample most likely related due to binarity. Excluding first overtone and multi-mode cepheids and applying some other criteria reduces the sample to about 200 stars. The derived PL(Z) relations depend strongly on the parallax zero-point offset. The slope of the PL relation is found to be different from the relations in the LMC at the 3{sigma} level. Fixing the slope to the value found in the LMC leads to a distance modulus (DM) to the LMC of order 18.7mag, larger than the canonical distance. The canonical DM of around 18.5 mag would require a parallax zero-point offset of order -0.1mas. Given the strong correlation between zero point, period and metallicity dependence of the PL relation, and the parallax zero-point offset there is no evidence for a metallicity term in the PLZ relation. The GDR2 release does not allow us to improve on the current distance scale based on CCs. The value of and the uncertainty on the parallax zero-point offset leads to uncertainties of order 0.15mag on the distance scale. The parallax zero-point offset will need to be known at a level of 3{mu}as or better to have a 0.01mag or smaller effect on the zero point of the PL relation and the DM to the LMC.2018A&A...619A...8Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/619/A8CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)I/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/619/A8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/619/A8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/619/A8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/619/A8https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/619/A8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/619/A8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/619/A8/table1 (stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/619/A8/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/619/A8/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/619/A8/table1?GETtext/xml+votable180.050000true91.645608126.32922360.0055555555555555565/9482 6/1239 1331 1340 1348 1388 1402 1411 1421 1426 1429 1431-1432 1441 1445 1467 1625 1631 1765 1824 1829 1836 1858 1920 1985 2805 3000 3005 3008 3022 3033 3045 3047 3050 3052 3054 3059-3060 3063 3131 3157 3239 3252 3255 3261 3263 3284-3285 3304 3306 3309 3322 3328 3342 3361-3362 3365 3459 3589 3599-3601 3616 3627 3629 3631-3632 3641 3645 3656 3663 3712-3714 3722 3731 3849 4095 12321 12436 12685 12846 12934 12963 12968 12970-12971 13166 13201 13288 13309-13310 13931 13933 13961 13990 14009 14047 14059 14075 14205 14212 14229 14238-14239 14246 14251 14260 14262 14265 14267 14271 14282-14283 14291-14292 14295 14301 14303 14317 14320-14321 14323-14324 14328-14329 14404 14407 14409 14411 14424 14427 14430 14436 14445 14449 14453 14455 14457 14469 14533 14601-14602 14607 14625 14629-14630 14634 14637 14640 14653 14690 14698 14709 14718 14736 14770 15360 15378 15388 15392-15393 15396 15425 15429 15461 15585 15618 15632-15633 15660 15698 20827 20833 21514 21542 21632 21648 21671 21679 21683 21686 22020 22044 22064 22068-22069 22071 22074 22106 22115-22116 22122 22124 22149 22169 22207 22210 22214 22219 22221 22223 22227 22255 22267 22438 23619 23622 23635 23660 23662 23669-23670 23762 23778 23841 23846 23852 23922 23936 24002 24146 24153 24226 24326 24340 24372 24411 24424 24450 24453 24478-24479 24527 28717 28779 28808 28819 28831 28875 28893 28916 28991 29032 29081 29089-29090 29095 29104 29106 29110 29126 29166 29173 29216 29468 29519 29523 29533 29665 29772 29852 29875 29897 29999 30128 30211 30219 30222-30223 30235 30245 30256 30258 30265 30270 30307 30311 30321-30322 30333 30438 30504 30580 30596 30609 30641 30646 32012 32064 32074 33804 37203 37223 37235 37245 37273 37303 37330 37332 37334 37336 37339-37340 37357 37364 37674 37713 37721 37723 37729 37741 37745-37746 37757 37828-37829 37856 37867 37870 37888 37895 37903-37904 37915 37917 37923 37926-37927 37938 37963 38020 38022-38024 38026 38029 38049 38627 39125 39216-39217 39231-39232 39244-39245 39348 39374 39410 39766 39771 39790 39794 39796 39883 39886 39889 39891-39892 39908 39920 39926 39933 39935 40491 40494 40580 40608 41375 41383 41385 41419 41461 41556 41599 41605 41608 41631 41667 41673-41674 41681 41697-41698 41721-41722 41737 41761-41762 41768 41810 41813 41833 41842 41862 42153 42155-42156 42185 42297 42352 42378 42385 42445 42500 42820 43013 43022 43028 43041 43047 43056-43057 43060https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/619/A8?format=asciiOpticaldefaultJ/A+A/619/A8/table1starsSimbadNameSimbad column added by the CDSmeta.idcharVmagV-band magnitudemagphot.mag;em.opt.VfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameVariable star name (1)meta.id;meta.maincharTypeClassification of the variability (2)meta.code.class;src.varcharn_Type[+] Note on Type (3)meta.notecharPeriodPulsation period, taken from the VSX catalog (Watson et al., 2006, Cat. B/vsx)dtime.periodfloatr_VmagReference for V magnitude (4)meta.ref;pos.frameintJmagJ-band magnitudemagphot.mag;em.IR.Jfloatr_JmagReference for JHK magnitudes (5)meta.ref;pos.framecharHmagH-band magnitudemagphot.mag;em.IR.HfloatKmagK-band magnitudemagphot.mag;em.IR.Kfloato_Kmag? Available number of K magnitudes if multiple singe-epoch data was used to obtain the median magnitude (6)meta.numbercharQualIn case of single-epoch 2MASS data the quality-flag is listed if it is not AAAmeta.code.qualcharE(B-V)Colour excess (some corrections have been applied, see main text)magphot.color.excessfloatr_E(B-V)Reference for E(B-V) (7)meta.ref;pos.frameinte_E(B-V)rms uncertainty on colour excessmagstat.errorfloat[Fe/H]1? Iron abundancephys.abund.Fefloatnullabler_[Fe/H]1? Reference for [Fe/H]1 (8)meta.refintnullable[Fe/H]2? Iron abundancephys.abund.Fefloatnullabler_[Fe/H]2? Reference for [Fe/H]2 (8)meta.refintnullable[Fe/H]3? Iron abundancephys.abund.Fefloatnullabler_[Fe/H]3? Reference for [Fe/H]3 (8)meta.refintnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main