J/AJ/169/310ivo://CDS.VizieR/J/AJ/169/310CDSDonev E.Ivezic Z.2026-03-18T08:19:42Z2026-03-18T09:00:41ZCDS support team

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

cds-question@unistra.frvariable-starsphotometryvisible-astronomyWe analyzed the incidence and properties of RR Lyrae stars that show evidence for amplitude and phase modulation (the so-called Blazhko Effect) in a sample of ~3000 stars with LINEAR and ZTF light curve data collected during the periods of 2002-2008 and 2018-2023, respectively. A preliminary subsample of about ~500 stars was algorithmically preselected using various data quality and light curve statistics, and then 228 stars were confirmed visually as displaying the Blazhko effect. This sample increases the number of field RR Lyrae stars displaying the Blazhko effect by more than 50% and places a lower limit of (11.4+/-0.8)% for their incidence rate. We find that ab type RR Lyrae that show the Blazhko effect have about 5% (0.030 day) shorter periods than starting sample, a 7.1{sigma} statistically significant difference. We find no significant differences in their light curve amplitudes and apparent magnitude (essentially, signal-to-noise ratio) distributions. No period or other differences are found for c type RR Lyrae. We find convincing examples of stars where the Blazhko effect can appear and disappear on timescales of several years. With time-resolved photometry expected from the Legacy Survey of Space and Time, a similar analysis will be performed for even larger samples of field RR Lyrae stars in the southern sky and we anticipate a higher fraction of discovered Blazhko stars due to better sampling and superior photometric quality.2025AJ....169..310Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/169/310CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/ApJ/598/597 : Frequency analysis of fundamental-mode RR Lyrae (Alcock+, 2003)J/MNRAS/377/1263 : Multiperiodic RR Lyrae in ASAS catalog (Szczygiel+, 2007)J/AcA/59/1 : VI light curves of LMC RR Lyrae stars (Soszynski+, 2009)J/A+A/520/A108 : CoRoT 101128793 light curves (Poretti+, 2010)J/ApJ/708/717 : Light curve templates of RR Lyrae stars (Sesar+, 2010)J/AcA/60/165 : VI light curves of SMC RR Lyrae (Soszynski+, 2010)J/AcA/61/1 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2011)J/MNRAS/411/1744 : Observations of RR Lyr stars in M5 (Szeidl+, 2011)J/AJ/146/101 : LINEAR. III. Catalog of periodic variables (Palaversa+, 2013)J/AJ/146/21 : LINEAR. II. Catalog of RR Lyrae stars (Sesar+, 2013)J/A+A/549/A101 : Known Galactic field Blazhko stars (Skarka, 2013)J/ApJS/213/31 : Blazhko effect from 4yr of Kepler data (Benko+, 2014)J/A+A/570/A100 : BVRc light curves of 5 CoRoT RR Lyrae stars (Szabo+, 2014)J/MNRAS/466/2602 : Blazhko effect in Galactic RR Lyrae (Prudil+, 2017)J/MNRAS/480/1229 : Blazhko effect in the 1st overtone RR Lyrae (Netzel+, 2018)J/MNRAS/494/1237 : Blazhko effect in Galactic RR Lyrae II (Skarka+, 2020)J/A+A/674/A18 : Gaia DR3. The RR Lyrae sample (Clementini+, 2023)J/A+A/678/A104 : M80 anomalous variable stars (Molnar+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/169/310https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/169/310http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/169/310https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/169/310https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/169/310http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/169/310GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/169/310/table1 (Confirmed Blazhko stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/169/310/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/169/310/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/169/310/table1?GETtext/xml+votable180.050000true120.751256751.86618750.0055555555555555566/4164 4171 4177 4192 4209 4253 4295 4335 4399 4406 4419 4426 4450 4503 4514 4830 4882 4920 4927 4937 5140 5158 5189 5194 5249 5253 5353 5367 5392 5439 5647 5970 5975 5979 6037 6462 6527 6652 7176 7244 7255 7308 7373 7404 8216 8253 8414 8464 8494 8573 8588 8612 8621 8682 8887 8890 8913 9006 9031 9050 9062 9145 9202 9223 9249 9294 9332-9333 9360 9370 9429 9447 9451 9510 9518 9801 9850 9862 9865 9868 9888 9890 9898 9931 9984 10025 10030-10031 10158 10182 10196 10199 10211 10385 10393 10458 10473 10479 10533 10611 10634 10661 10735 10758 10813 10866 10901 10920 11048 11107 11130 11333 11354 11464 11478 11552 11609 11768 11777 11851 11938 25590 25597 25851 25896 25949 25966 25973 25983 25993 25998 26023 26046 26054 26101 26110 26125 26136 26157 26174 26208 26213 26215 26217 26261 26272 26305 26322 26375 26403 26409 26534 26562 26901 26956 26958 26962 26975 26990 26993 27058 27080 27083 27085 27090 27094 27099 27120 27126 27252 27327 27353 27367 27371 27435 27513 27516 27533 27551 27588 27616 27644 27666 27669 27682 27693-27694 27706 27714 27719-27720 27728 27736 27803 27810 27972 28077 28141 28157 28163 28205 28344 28375 28386 28456 28471 28483 28501 28566 28589 28624 28652 28670 31332 31352 31457 31616 31698 32433 32446 32502 44792https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/169/310?format=asciiOpticaldefaultJ/AJ/169/310/table1Confirmed Blazhko starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLINEAR[158779/24216004] LINEAR identifiermeta.id;meta.mainintPer-L[0.26/0.73] Computed light-curve period, LINEARdtime.perioddoublePer-Z[0.26/0.73] Computed light-curve period, ZTFdtime.perioddoubleN-L[150/638] Number of data points, LINEARmeta.numberintN-Z[168/3881] Number of data points, ZTFmeta.numberintchi2r-L[0.7/6.6] Robust {chi}^2^ per degree of freedom, LINEARstat.fit.chi2floatchi2r-Z[1.1/11.6] Robust {chi}^2^ per degree of freedom, ZTFstat.fit.chi2floatchi2-L[0.5/121.4] Ordinary {chi}^2^ per degree of freedom, LINEARstat.fit.chi2floatchi2-Z[1.3/186.9] Ordinary {chi}^2^ per degree of freedom, ZTFstat.fit.chi2floatAmp-L[0.26/1.24] Light-curve amplitude, LINEARmagsrc.var.amplitudefloatAmp-Z[0.23/1.49] Light-curve amplitude, ZTFmagsrc.var.amplitudefloatdAmp[0/0.5] Difference, |Amp-L - Amp-Z|magsrc.var.amplitudefloatStr-Bp-L[1.4/3.8] Strength, Blazhko peaks, LINEARspect.line.strength;stat.maxfloatSimbadSimbad column added by the CDSmeta.ref.urlcharStr-Bp-Z[1.37/3.84] Strength, Blazhko peaks, ZTFspect.line.strength;stat.maxfloatPer-Bp-L[6.6/357.8] Period of Blazhko peaks, LINEARdtime.perioddoublePer-Bp-Z[6.5/356.6] Period of Blazhko peaks, ZTFdtime.perioddoubleType[1,2] Light-curve type (1)meta.code;stat.fit;src.classintFlagDetection significance flag (2)meta.code.errorcharB-s[0/9] Selection score, number of points scored from the selection algorithm (Section 3.1) (3)meta.code.qualintB-f[1/2] Selection score, Section 3.2 (4)meta.code.qualintZTFLink to ZTF catalog (J/ApJS/249/18) data for objects within 1"meta.ref.urlintnullable_RAPosition from Simbad (right ascension part)degpos.eq.ra;meta.main_DEPosition from Simbad (declination part)degpos.eq.dec;meta.main