J/A+A/707/A58ivo://CDS.VizieR/J/A+A/707/A58doi:10.26093/cds/vizier/bc-p3/lfiCDSHajdu G.Jurcsik J.Catelan M.Pietrzynski G.Hocde V.Soszynski I.,Udalski A.Lee C.-U.Kim D.-J.2026-04-02T20:03:14Z2026-02-26T08:25:23ZCDS support team

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

cds-question@unistra.frvariable-starsphotometryvisible-astronomyA number of RR Lyrae stars show variable mean magnitudes in the OGLE survey light curves of the Galactic bulge. Hitherto this phenomenon was not studied, as it was generally assumed to be related to problems with the photometry. We investigate whether the mean magnitude variability of RR Lyrae variables is due to genuine astrophysical phenomena. We make use of the extended, and in many cases overlapping, light curves from multiple microlensing surveys, to study RR Lyrae stars with apparent mean-magnitude variations. A modified Fourier-series based fitting method is introduced to analyze the light curves showing mean-magnitude variations. Data from infrared surveys are also used to construct spectral energy distributions (SEDs). 72 stars are presented where the mean-magnitude variations are most probably of genuine astrophysical origin, and not the result of problems with the photometry. The ratio of variation between the V and I bands is compatible with variable extinction by dust in most cases, but no infrared excess is detected in the SEDs. The occurrence rate of the phenomenon, after correcting for selection effects, is ~0.9% among RR Lyrae variables in the OGLE bulge fields.2026A&A...707A..58Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/707/A58CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AcA/64/177 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2014)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/707/A58https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/707/A58http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/707/A58https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/707/A58https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/707/A58http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/707/A58GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/707/A58/table1 (Property results of analysis for RR Lyrae with detected mean-magnitude changes final sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/707/A58/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/707/A58/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/707/A58/table1?GETtext/xml+votable180.050000true261.6742958-29.58309530.0055555555555555565/7183 7205 6/28717-28718 28723 28728 28776 28778-28779 28782 28801 28819 28829 28838 28844-28845 28857 28860 28865-28868 28870-28871 28876-28877 28880 28882-28884 28905https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/707/A58?format=asciiOpticaldefaultJ/A+A/707/A58/table1Property results of analysis for RR Lyrae with detected mean-magnitude changes final samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameOGLE ID of RR Lyrae star (Star)meta.id;meta.maincharPPulsation period adopted for the analysis (Period)dtime.perioddoubleCorType of phase correction applied to data (OmC) (1)meta.codecharNbpsAdopted number of breakpoints per season (Nbps)meta.numberintNIbandNumber of data points in the I band (NI)meta.numberintNIrNumber of removed I band data points (NI_r)meta.numberintNVbandNumber of data points in the V band (NV)meta.numberintNVrNumber of removed V band data points (NV_r)meta.numberintAmpAmplitude of mean-magnitude changes (dIDR)magphot.mag;src.var.amplitude;em.optfloatrIVAmplitude ratio of the mean-magnitude changes between the I and V bands (rIV)src.var.amplitude;arith.ratio;em.optfloate_rIVUncertainty in rIV (e_rIV)stat.errorfloatu_rIV[*] Flag for uncertain rIV values (n_rIV)meta.code.errorcharNFINumber of harmonics adopted for the Fourier series in the I band (FI)meta.numberintNFVNumber of harmonics adopted for the Fourier series in the V band (FV)meta.numberintdAICAkaike Information Criterion difference in the V band between the mean-magnitude changing and simple Fourier series models (dAIC) (2)stat.param;arith.diff;meta.modelledfloatSimbadSimbad column added by the CDSmeta.ref.urlcharLCLong-term light-curve behavior (LC) (3)meta.codeintSoszynski+2014Display the VI light curves of Galactic Bulge RR Lyrae from Soszynski et al. 2014AcA....64..177S, Cat. J/AcA/64/177meta.ref.urlcharOGLELink for OGLE OCVS object pagemeta.ref.urlchar_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