J/ApJS/276/25ivo://CDS.VizieR/J/ApJS/276/25doi:10.26093/cds/vizier/bb-8m-sCDSKleftogiannis G.D.Christopoulou P.-E.Papageorgiou A.2026-08-03T07:26:00Z2025-12-04T12:31:36ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsvariable-starssurveysphotometryvisible-astronomyAsymmetries between the two maxima of the light curves of contact binaries, known as the O'Connell effect, have been identified using the All Sky Automated Survey, All-Sky Automated Survey for Supernovae, Northern Sky Variability Survey, Optical Gravitational Lensing Experiment, and Optical Monitoring Camera sky surveys. The morphology of the mean light curve has been analyzed for a total of 43659 objects already classified as contact binaries. After applying several filters and criteria, we present a sample of 797 systems representing the largest sample to date of maxima asymmetries of EW-type binaries with |{Delta}m| up to 0.13 mag. We also added information on distance and temperature from Gaia DR3 and The Large Sky Area Multi-Object Fiber Spectroscopic Telescope. We investigated the statistical distributions of periods, temperatures, signs of maximum asymmetry, O'Connell effect ratio and light-curve asymmetry indices of asymmetry, and their correlations. While starspots could explain the different maxima asymmetries in stars with convection zones and differential rotations, the discovery of sizeable asymmetric maxima in 161 early-type systems above the upper limit of the Kraft break (T>6700K) may indicate a different mechanism. We also report systems with peculiar unequal maxima.2025ApJS..276...25Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/276/25CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/287 : Northern Sky Variability Survey (NSVS) (Wozniak+, 2004)II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)J/AcA/48/563 : BVI phot. of OGLE SMC eclipsing binaries (Udalski+, 1998)J/AJ/119/1901 : ROTSE all-sky surveys for variable stars (Akerlof+, 2000)J/AcA/53/1 : OGLE eclipsing binaries in LMC (Wyrzykowski+, 2003)J/AJ/138/466 : NSVS variables automated classification (Hoffman+, 2009)J/AcA/61/103 : VI light curves of LMC eclipsing binaries (Graczyk+, 2011)J/AJ/141/83 : Kepler Mission. I. Eclipsing binaries in DR1 (Prsa+, 2011)J/A+A/548/A79 : INTEGRAL-OMC opt. variable sources (Alfonso-Garzon+, 2012)J/AJ/145/80 : LCs of HS Aqr, EG Cep, VW LMi, DU Boo (Djurasevic+, 2013)J/AcA/63/323 : OGLE-III SMC eclipsing binary stars (Pawlak+, 2013)J/AcA/63/115 : OGLE-III Gal. disk eclipsing binaries (Pietrukowicz+, 2013)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/AJ/151/68 : Kepler Mission. VII. Eclipsing binaries in DR3 (Kirk+, 2016)J/AcA/66/421 : Eclipsing binaries in the Magellanic System (Pawlak+, 2016)J/AcA/66/405 : Gal. bulge eclipsing & ellipsoidal bin. (Soszynski+, 2016)J/AJ/153/231 : BVR photometry of EPIC 211957146 (Sriram+, 2017)J/AJ/156/241 : A first cat. of var. stars measured by ATLAS (Heinze+, 2018)J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)J/ApJS/255/1 : Morphology of OGLE LCs of Eclipsing binaries (Bodi+, 2021)J/ApJS/254/10 : Compilation of W UMa stars (Latkovic+, 2021)J/MNRAS/507/104 : Ellipsoidal variables in ASAS-SN catalog (Rowan+, 2021)J/A+A/663/A115 : Contact binary var. X-ray emission within 1kpc (Liu+, 2022)J/ApJS/258/16 : TESS Eclipsing Binary stars. I. Sectors 1-26 (Prsa+, 2022)J/A+A/674/A19 : Ellipsoidal variables with compact companions (Gomel+ 2023)J/MNRAS/522/29 : 15000 ellipsoidal binary candidates in TESS (Green+, 2023)J/AJ/165/259 : TESS phot. & radial velocities for 6 K-binaries (Liu+, 2023)J/A+A/677/A137 : Stellar variability in Gaia DR3 (Maiz Apellaniz+, 2023)J/AJ/167/280 : Photometry and spectroscopy of V505 Lac (Jeong+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/276/25https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/276/25http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/276/25https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/276/25https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/276/25http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/276/25GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/276/25/table2 (Properties of 797 systems with maxima asymmetry (MA))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/276/25/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/276/25/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/276/25/table2?GETtext/xml+votable180.050000true237.35589-33.746280.0055555555555555565/9482 6/57 237 654 734 872 1024 1033 1060 1214 1305 1570 1669 1679 2151 2173 2290 2551 2680 2702 2824 2827 2875 2906 2988 3042 3245 3352 3450 3513 3558-3559 3631 3737 3912 4012 4061 4149 4216 4280 4376 4629 4707 4810 4983 4986 5043 5084 5108 5469 5653 5836 5979 6181 6239 6258 6471 6569 6590 6653 6671 6674 6707 6725 6740 6779 6790 6844-6845 6949 7006 7057 7064 7074 7325 7429 7512 7724 7758 7804 7828 7840 7895 7918 8088 8204 8356 8550-8551 8608 8663 8696 8843 9325 9438 9576 9582-9583 9605 9613 9730 9775 9817 10007 10075 10168 10308 10450 10530 10792 11128 11278 11336 11552 11601 11614 11645 11805 11977 12127 12150 12330 12612 12755 12772 12792 12795 12995 13111 13160 13165 13281 13396 13451 13479 13490 13507 13578 13617 13664 13722 13755 13800 13848 13926 13933 13946 14019 14217 14337 14350 14413 14479 14684 14756 14878 14974 14989 15032 15144 15206 15246 15259 15284 15584 15616 15900 15973 16066 16311 16400 16411 16434 16781 16903 16978 17246 17280 17328 17375 17378 17594 17741 18180 18470 18531 18756 18892 18986 18988 19019 19230 19236 19255 19282 19301 19307 19466 19831 19934 20060 20074 20096 20105 20112 20121 20385 20441 20463 20496 20538 20590 20633 20705 20731 20762 20776 20782 20803 20837 20946 21080 21142 21219 21243 21349 21411 21425 21552 21596 21655 21659 21669 21713 21732 21749 21768 21777 21783 21850 22004 22042 22107 22178 22284 22293 22495 22704 22742 22755 22792 22835 22876 22991 23003 23053 23125 23135 23368 23494 23503 23777 23833 24041 24172 24426 24531 24567 24637 24820 25063 25164 25514 25591 25748 26002 26018 26221 26275 26401 26571 26607 26650 26790 26815 26818 26967 27011 27113 27277 27285 27369 27441 27708 27749 27821 27948 28064 28143 28149 28457 28679 28735 28775 28866 28869 28925 29058 29077 29123 29149 29151 29333 29346 29470 29488 29506 29516 29678 29724 29851 29880 30046 30106 30162 30291 30376-30377 30456 30540 30566 30712 30770 30794 30823 30843 30894 30899 30908 31002 31039 31052 31252 31338 31439 31533 31597 31602 31789 31831 31834 31859 31888 32101 32131 32146 32231 32287 32385 32478 32551 32553 32664 32701 32773 32822 32838 32932 32984 33041 33047 33054 33090-33091 33099 33168 33273 33294-33295 33324 33398 33915 33977 34071 34077 34253 34284 34636 35034 35176 35208 35279 35298 35394 35435 35507 35647 35814 35849 35903 36128 36136 36149 36154 36158 36181 36237 36537 36672 36784 37060 37141 37231 37243 37245-37247 37317 37328-37329 37332-37333 37371-37372 37458 37475 37495 37530 37546 37607 37638 37652 37674 37721 37818 37843 37852 37871 37904-37905 37912 37914 37922-37923 37975 38031 38076 38200 38224 38251 38284 38387 38435 38552 38627 38674 38917 38939 38982 39088 39187 39204 39215 39240 39289 39298 39336 39507 39509 39534 39539 39567 39670 39765 39768 39779-39780 39835 39893 39931 39957 39998 40092 40133 40145 40195 40199 40279 40309 40316 40353 40387 40412 40427 40445 40474 40552 40581 40678 40727 40804 40902 40938 41019 41187 41211 41216 41311 41432-41433 41621 41623 41628-41629 41631 41666-41667 41672-41673 41706 41755 41807 41882 41896 41917 41950 42023 42040 42156 42186 42238 42325 42359 42473 42485 42487 42541 42624 42658 42671 42740 42853 42923 43023 43040 43199 43282 43332 43411 43594 43650 43696 43730 43836 43841 43974 44049 44058 44212 44232 44428 44454 44577 44608 44611 44646 44684 44690 44741 44968 45010 45103 45106 45135 45297 45685 45707 45755 45810 45851 45989 46181 46247 46390 46445 46469 46557 46636 46644 46683 46829 46975 47199 47211 47259 47264 47298 47382 47418 47458 47523 47539 47547 47564 47674 47804 47874 47925 47950 48164 48310 48408 48474 48522 48554 48659 48668 48726 48749 48755 48779 48810 48824 48876 48895 48912 48928 49042 49082https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/276/25?format=asciiOpticaldefaultJ/ApJS/276/25/table2Properties of 797 systems with maxima asymmetry (MA)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSystem Namemeta.id;meta.maincharFlagFlag (1)meta.code.errorcharRAJ2000Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainPer[0.2/1.9] Perioddtime.perioddoubleNobs[77/3100] Number of observationsmeta.numberintDelm[-0.13/0.1] Difference in magnitude between two maxima, {Delta}mmagphot.mag;arith.difffloatDelm/Afit[-0.09/0.12] Ratio, Delm to amplitude, |{Delta}m|/A_fit_src.var.amplitude;arith.ratiofloatDeltaINormalized flux, {Delta}Iphot.flux;arith.ratio;em.opt.IcharOER[0.499/1.88] O'Connell Effect Ratio indicator of asymmetry, equation 3stat.fit.paramfloatLCA[0.007/0.31] LC Asymmetry indicator of asymmetry, equation 4stat.fit.paramfloatONameOther namemeta.idcharASASSNDisplay data from ASAS-SN (II/366) within 1.5"meta.ref.urlintnullableASAS3Display data from ASAS (II/264) within 10"meta.ref.urlintnullableNSVSDisplay data from NSVS (Hoffman+ 2009, J/AJ/138/466) within 10.5"meta.ref.urlintnullableOGLEDisplay data from OGLE (Udalski+ 1998, J/AcA/48/563; Wyrzykowski+ 2003, J/AcA/53/1; Graczyk+ 2011, J/AcA/61/103; Pawlak+ 2013, J/AcA/63/323 and Pietrukowicz+ 2013, J/AcA/63/115) within 3"meta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idcharnullable