J/A+A/703/A166ivo://CDS.VizieR/J/A+A/703/A166CDSHernandez-Diaz S.Stelzer B.Schwope A.Munoz-Giraldo D.2025-11-14T08:05:58Z2025-11-14T09:05:23ZCDS support team

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

cds-question@unistra.frcataclysmic-variable-starsorbitsphotometryvisible-astronomyDetermining the orbital periods of cataclysmic variable stars (CVs) is essential for confirming candidates and for the understanding of their evolutionary state. The Transiting Exoplanet Survey Satellite (TESS) provides month-long photometric data across nearly the entire sky that can be used to search for periodic variability in such systems. This study aims to identify and confirm the orbital periods for members of a recent compilation of magnetic CVs (known as polars) using TESS light curves. In addition to providing the periods, we set out to investigate their reliability, and hence the relevance of TESS for variability studies of CVs. Four period-search methods were used, namely the Lomb-Scargle periodogram, the autocorrelation function (ACF), sine fitting, and Fourier power spectrum analysis, to detect periodic signals in TESS light curves. We investigated the correlation between noise level and TESS magnitude by "flattening" the observed TESS light curves, effectively isolating the noise from the periodic modulation. To evaluate the reliability of the period detections, we developed a probabilistic framework for the detection success across signal-to-noise ratios in the power spectral density of observed light curves. Ninety-five of the 217 polars in our sample have pipeline-produced TESS two-minute cadence light curves available. The results from our period search are overall in good agreement with the previously reported values. Out of the 95 analysed systems, 85 exhibit periods consistent with the literature values. Among the remaining ten objects, four are asynchronous polars, where TESS light curves resolve the orbital period, the white dwarf's spin period, and additional beat frequencies. For four systems, the periods detected from the TESS data differ from those previously reported. For two systems, a period detection was not possible due to the high noise levels in their light curves. Our analysis of the flattened TESS light curves reveals a positive correlation between noise levels - expressed as the standard deviation of the flattened light curve - and TESS magnitude. Our noise level estimates resemble the rmsCDPP, a measure of white noise provided with the TESS pipeline products. However, our values for the noise level are systematically higher than the rmsCDPP indicating red noise and high-frequency signals hidden in the flattened light curves. Additionally, we present a statistical methodology to assess the reliability of period detections in TESS light curves. We find that for TESS magnitudes >~17, period detections become increasingly unreliable. Our study shows that TESS data can be used to reliably and efficiently determine orbital periods in CVs. The developed methodology for period detection, noise characterisation, and reliability assessment can be systematically applied to other variable star studies, thus improving the robustness of period measurements in large photometric data sets.2025A&A...703A.166Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/703/A166CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/703/A166https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/703/A166http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/703/A166https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/703/A166https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/703/A166http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/703/A166GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/703/A166/tablea1 (properties and period search results for 95 polars with TESS 2-minute cadence light)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/703/A166/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/703/A166/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/703/A166/tablea1?GETtext/xml+votable180.050000true286.776001849651769.1456804519520.0055555555555555566/529 763 974 1387 2012 2134-2135 4144 4377 5120 5558 5570 6193 6467 6750 7607 7810 7828 8552 8693 8877 9577 9618 9765 10126 11112 11122 11333 11351 12574 12627 12649 13024 13902 14641 15090 15255 15385 15869 16072 17818 18703 19363 20025 20212 20436 20847 21630 21966 22020 22977 23469 24481 25909 26287 27545 28221 28561 29795 30129 31361 31997 33360 33378 33498 33713 33930 34097 34655 35824 35936 36129 36234 36721 37204 37891 38492 39207 40113 40235 40271 40293 40640 41823 41876 43321 43386 43908 45671 45814 45855 46737 47313 47496 491121.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/703/A166?format=asciiOpticaldefaultJ/A+A/703/A166/tablea1properties and period search results for 95 polars with TESS 2-minute cadence lightrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSystemObject's common namemeta.id;meta.maincharGaiaDR3Gaia identifier from data release 3meta.idRA_ICRSGaia DR3 Right Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSGaia DR3 Declination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainTICTESS Input Catalogue identifiermeta.idSectorsObserved TESS sectorsobs.fieldcharTmagTESS magnitudemagphot.mag;em.optfloate_TmagUncertainty in TESS magnitudemagstat.error;phot.magfloatBPmagGaia BP mean magnitudemagphot.mag;em.opt.BfloatRPmagGaia RP mean magnitudemagphot.mag;em.opt.RfloatGmagGaia G mean magnitudemagphot.mag;em.optfloatPorbLS? Lomb-Scargle sector-average orbital periodmintime.perioddoublenullablee_PorbLS? Uncertainty in PorbLSminstat.errordoublenullablePorbACF? Autocorrelation function sector-average orbital periodmintime.perioddoublenullablee_PorbACF? Uncertainty in PorbACFminstat.errorfloatnullablePorbSINE? Sine fitting sector-average orbital periodmintime.perioddoublenullablee_PorbSINE? Uncertainty in PorbSINEminstat.errorfloatnullablePorbFS? Fourier power spectrum sector-average orbital periodmintime.perioddoublenullablee_PorbFS? Uncertainty in PorbFSminstat.errordoublenullablePorb? Final adopted orbital periodmintime.perioddoublenullablee_Porb? Uncertainty in final Porbminstat.errordoublenullableCorrFlag[0/1] 1/2Porb correction flag (1)meta.codeintPorblitLiterature-reported orbital periodmintime.perioddoubler_PorblitLiterature source for Porblitmeta.ref;pos.framecharSimbadNameSimbad column added by the CDSmeta.idcharnullable