J/A+A/709/A151ivo://CDS.VizieR/J/A+A/709/A151CDSHocde V.Moskalik P.Nardetto N.Kervella P.Pilecki B.Smolec R.,PietrzyNski G.Gieren W.Hajdu G.Gallenne A.Bailleul M.C.Bras G.,Wielgorski P.Breuval L.Merand A.Rathour R.S.Espinoza-Arancibia F.,Kiviaho W.Apostolova B.Sivkova K.2026-05-19T14:14:26Z2026-05-13T07:57:55ZCDS support team

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

cds-question@unistra.frvariable-starsphotometryvisible-astronomyradial-velocityRadial velocity (RV) curves of Cepheids are essential for studying their pulsation properties and also for measuring their distance via the parallax-of-pulsation method. Although precise RV curves are available for hundreds of Cepheids, it is still not possible to predict the complete RV curve from other observables such as their pulsation period or metallicity. This paper aims to develop the first method of reconstructing the shape of the RV curves of short-period fundamental-mode Cepheids, based exclusively on their pulsation period and the morphology of their V-band light curves (LCs). We compiled a dataset of high-quality spectroscopic and photometric measurements from the literature for 81 short-period fundamental-mode Galactic Cepheids up to a pulsation period of 8 days, enabling the precise determination of the Fourier parameters and their uncertainties. By performing a detailed comparative analysis of their shapes, we investigated correlations between LC and RV Fourier parameters and used these relations to reconstruct the RV curves. We further assessed the accuracy of these reconstructions by examining potential metallicity effects with an additional dataset of 24 metal-poor Cepheids. For pulsation periods between 3.5 and 7.0 days, we found tight correlations between different combinations of LC and RV Fourier parameters up to order 7. In particular, we discovered that the ratios R_21_(RV)/R_21_(LC) and R_31_(RV)/R_31_(LC) are tightly correlated with the pulsation period. These relationships enable the reconstruction of RV curves of Cepheids with their LC. The reconstructed curve has an uncertainty of about 0.60km/s relative to the Fourier fit of true spectroscopic RV measurements. For individual Cepheids, the reconstructed RV curves integrated along the pulsation cycle (i.e. the linear radius variations) are accurate to less than 1% and precise to within 4.16% in comparison to the integrated true spectroscopic RV curves. Last, our sample of metal-poor Cepheids shows a good agreement with the empirical relations calibrated on Galactic pulsators, indicating that the method of reconstruction is weakly dependent on metallicity. For the first time, we present a method of reconstructing the shape of the RV curves of Cepheids using solely the V-band LC and the pulsation period. This approach provides a valuable tool for the reconstruction of RV curves for extragalactic Cepheids through photometric data alone. It opens the road to a purely photometric parallax-of-pulsation method in the context of photometric surveys, such as the Vera Rubin Telescope. Further calibration in different photometric bands and for a larger metallicity baseline will be useful to improve the method.2026A&A...709A.151Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/709/A151CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/709/A151https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/709/A151http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/709/A151https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/709/A151https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/709/A151http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/709/A151GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/709/A151/table_rv (Fourier parameters of RV curves for the calibrating (table A4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/709/A151/table_rv?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/709/A151/table_rv?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/709/A151/table_rv?GETtext/xml+votable180.050000true243.7281369-53.33842890.005555555555555556Cone search capability for table J/A+A/709/A151/table_lc (Fourier parameters of V-band LC curves for the calibrating (table A3))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/709/A151/table_lc?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/709/A151/table_lc?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/709/A151/table_lc?GETtext/xml+votable180.050000true243.7281369-53.33842890.0055555555555555566/1239 3000 3005 3033 3252 3255 3261 13201 13931 13933 13990 14047 14260 14271 14295 14301 14436 14601 14637 14770 15429 15632-15633 21683 21686 22068-22069 22122 22169 22207 22214 22219 22255 23635 23662 23778 24411 28893 28991 29032 29081 29104 29110 29160 29216 29772 29875 30211 30580 30641 33054 33075 33098 33104-33105 33136-33137 33295 37713 37829 38627 39348 39883 39920 41721 41737 41862 42155-42156 42171 42297 42820 43022 43028 43060https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/709/A151?format=asciiOpticaldefaultJ/A+A/709/A151/table_rvFourier parameters of RV curves for the calibrating (table A4)SimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarCepheid identifiermeta.id;meta.maincharOrderOrder of the Fourier fitstat.fit.param;meta.modelledcharNdat[20/355] Number of data points (1)meta.numberintPeriodPulsation perioddtime.perioddoublesigmaFit residual scatterkm/sstat.fit.residual;stat.fit.param;meta.modelledfloatA1Fourier amplitude of first harmonickm/ssrc.var.amplitudefloate_A1Error of A1km/sstat.errorfloatR21Fourier amplitude ratio R21 = A2/A1src.var.amplitude;arith.ratiofloate_R21Error of R21stat.errorfloatphi21Fourier phase phi21 = phi2 - 2*phi1stat.fit.paramfloate_phi21Error of phi21stat.errorfloatR31Fourier amplitude ratio R31 = A3/A1src.var.amplitude;arith.ratiofloate_R31Error of R31stat.errorfloatphi31Fourier phase phi31 = phi3 - 3*phi1stat.fit.paramfloate_phi31Error of phi31stat.errorfloatR41? Fourier amplitude ratio R41 = A4/A1src.var.amplitude;arith.ratiofloatnullablee_R41? Error of R41stat.errorfloatnullablephi41? Fourier phase phi41 = phi4 - 4*phi1stat.fit.paramfloatnullablee_phi41? Error of phi41stat.errorfloatnullableR51? Fourier amplitude ratio R51 = A5/A1src.var.amplitude;arith.ratiofloatnullablee_R51? Error of R51stat.errorfloatnullablephi51? Fourier phase phi51 = phi5 - 5*phi1stat.fit.paramfloatnullablee_phi51? Error of phi51stat.errorfloatnullableR61? Fourier amplitude ratio R61 = A6/A1src.var.amplitude;arith.ratiofloatnullablee_R61? Error of R61stat.errorfloatnullablephi61? Fourier phase phi61 = phi6 - 6*phi1stat.fit.paramfloatnullablee_phi61? Error of phi61stat.errorfloatnullableR71? Fourier amplitude ratio R71 = A7/A1src.var.amplitude;arith.ratiofloatnullablee_R71? Error of R71stat.errorfloatnullablephi71? Fourier phase phi71 = phi7 - 7*phi1stat.fit.paramfloatnullablee_phi71? Error of phi71stat.errorfloatnullable_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.mainJ/A+A/709/A151/table_lcFourier parameters of V-band LC curves for the calibrating (table A3)SimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarCepheid identifiermeta.id;meta.maincharNdat[20/1909] Number of data points (1)meta.numberintPeriodPulsation perioddtime.perioddoublesigmaFit residual scattermagstat.error;phot.magfloatA1Fourier amplitude of first harmonicmagsrc.var.amplitudefloate_A1Error of A1magstat.errorfloatR21Fourier amplitude ratio R21 = A2=- /A1src.var.amplitude;arith.ratiofloate_R21Error of R21stat.errorfloatphi21Fourier phase phi21 = phi2 - 2*phi1stat.fit.paramfloate_phi21Error of phi21stat.errorfloatR31? Fourier amplitude ratio R31 = A3=- /A1src.var.amplitude;arith.ratiofloatnullablee_R31? Error of R31stat.errorfloatnullablephi31? Fourier phase phi31 = phi3 - 3*phi1stat.fit.paramfloatnullablee_phi31? Error of phi31stat.errorfloatnullableR41? Fourier amplitude ratio R41 = A4=- /A1src.var.amplitude;arith.ratiofloatnullablee_R41? Error of R41stat.errorfloatnullablephi41? Fourier phase phi41 = phi4 - 4*phi1stat.fit.paramfloatnullablee_phi41? Error of phi41stat.errorfloatnullableR51? Fourier amplitude ratio R51 = A5=- /A1src.var.amplitude;arith.ratiofloatnullablee_R51? Error of R51stat.errorfloatnullablephi51? Fourier phase phi51 = phi5 - 5*phi1stat.fit.paramfloatnullablee_phi51? Error of phi51stat.errorfloatnullableR61? Fourier amplitude ratio R61 = A6=- /A1src.var.amplitude;arith.ratiofloatnullablee_R61? Error of R61stat.errorfloatnullablephi61? Fourier phase phi61 = phi6 - 6*phi1stat.fit.paramfloatnullablee_phi61? Error of phi61stat.errorfloatnullableR71? Fourier amplitude ratio R71 = A7=- /A1src.var.amplitude;arith.ratiofloatnullablee_R71? Error of R71stat.errorfloatnullablephi71? Fourier phase phi71 = phi7 - 7*phi1stat.fit.paramfloatnullablee_phi71? Error of phi71stat.errorfloatnullable_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.mainOrderOrder of the Fourier fitstat.fit.param;meta.modelledchar