J/AJ/159/189ivo://CDS.VizieR/J/AJ/159/189doi:10.26093/cds/vizier.51590189CDSLi K.Kim C.-H.Xia Q.-Q.Michel R.Hu S.-M.Gao X.Guo D.-F.Chen Xu2021-12-07T01:01:56Z2020-10-12T06:39:23ZCDS support team

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

cds-question@unistra.frmultiple-starsvisible-astronomystellar-radiistellar-massesIn this paper, we present the first light curve synthesis and orbital period change analysis of nine contact binaries around the short-period limit. It is found that all these systems are W-subtype contact binaries. One of them is a medium contact system while the others are shallow contact ones. Four of them manifest obvious O'Connell effect explained by a dark spot or hot spot on one of the component stars. Third light was detected in three systems. By investigating orbital period variations, we found that four of the targets display a secular period decrease while the others exhibit a long-term period increase. The secular period decrease is more likely caused by angular-momentum loss while the long-term period increase is due to mass transfer from the less massive component to the more massive one. Based on the statistic of 19 ultrashort-period contact binaries with known orbital period changes, we found that seven of them display long-term decrease (three of them also exhibit cyclic variations), ten of them manifest long-term increase while two of them only show cyclic variation, and that most of them are shallow contact binaries supporting the long timescale angular-momentum loss theory suggested by Stepien. For the three deep contact systems, we found that they are probably triple systems. The tertiary companion plays an essential role during their formation and evolution.2020AJ....159..189Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/159/189CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/345 : Gaia DR2 (Gaia Collaboration, 2018)V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)V/146 : LAMOST DR1 catalogs (Luo+, 2015)J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)J/ApJ/629/1055 : Evolution of close binary systems (Yakut+, 2005)J/AJ/134/2398 : Stellar SEDs in SDSS and 2MASS filters (Covey+, 2007)J/AJ/137/236 : CC Com and BV Dra light curves (Yang+, 2009)J/MNRAS/405/1930 : Period changes of EA-, EB- & EW-types binaries (Liao+, 2010)J/other/JAVSO/38.183 : Time of minima of eclipsing binaries (Samolyk+, 2010)J/A+A/528/A90 : SuperWASP short period eclipsing binaries (Norton+, 2011)J/AcA/62/97 : Times of minima for 13 eclipsing binaries (Zasche, 2012)J/AJ/145/100 : Differential BVR light curves of EP And (Lee+, 2013)J/A+A/549/A86 : Period change 143 SuperWASP eclipsing binaries (Lohr+, 2013)J/A+A/558/A71 : Times of minima for 1SWASP J234401.81-212229.1 (Lohr+, 2013)J/AJ/146/58 : Eclipse timings for NGC 6819-259 (Jeffries+, 2013)J/AJ/146/101 : LINEAR. III. Catalog of periodic variables (Palaversa+,2013)J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/AJ/150/1 : Eclipse timings of 27 eclipsing binaries (Hong+, 2015)J/AJ/157/207 : BVR_c_I_c_ light curve observations for VZ Lib (Liao+, 2019)http://wasp.cerit-sc.cz/form : SuperWASP data homepagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/159/189https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/159/189http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/159/189https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/159/189https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/159/189http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/159/189GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/159/189/stars (Informations and absolute parameters of the studied stars (Paste of table 1 and 8))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/159/189/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/159/189/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/159/189/stars?GETtext/xml+votable180.050000true7.637958357.72980560.0055555555555555566/420 678 3040 6585 9263 10817 20131 25949 27605https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/159/189?format=asciiOpticaldefaultJ/AJ/159/189/starsInformations and absolute parameters of the studied stars (Paste of table 1 and 8)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameEclipsing binary namemeta.id;meta.maincharf_Name[a] Flag on Name (1)meta.codecharIDIdentification as used in this articlemeta.idcharRAJ2000[0/22] Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000[1/57] Degree of declination (J2000)pos.eq.dec;meta.mainPer[0.19/0.23] Perioddtime.perioddoubleHJD[7675/8542] Heliocentric Julian Date; JD-2450000dtime.epochdoubleVmag[14.06/16.27] Visual magnitudemagphot.mag;em.opt.VfloatAmpl[0.21/0.68] Amplitudesrc.var.amplitudefloatf_Ampl[b] Flag on Ampl (1)meta.codecharRefReferences (2)meta.refNobsNumber of observations for this eclisping binary (link to table6)meta.numberintnullableMass1[0.13/0.68] Primary star masssolMassmeta.id;meta.mainfloatMass2[0.4/0.79] Secondary star masssolMassmeta.idfloata[1.26/1.66] Semi major axissolRadphys.angSize.smajAxis;src.orbitalfloatRad1[0.37/0.69] Primary star radiussolRadmeta.idfloatRad2[0.54/0.77] Secondary star radiussolRadmeta.idfloatLum1[0.04/0.23] Primary star luminositysolLumphys.luminosityfloatLum2[0.08/0.23] Secondary star luminositysolLumphys.luminosityfloatdM1/dt[-8.56/1.8] Mass loss of primary star0.1solMass.yr**-1phys.mass.lossfloate_dM1/dt[0.08/0.92] Error on dM1/dt0.1solMass.yr**-1stat.errorfloatJ/AJ/159/189/table6Eclipse timings for the nine starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identificationmeta.id;meta.maincharHJD[1491/8542] Heliocentric Julian Date; JD-2450000dtime.epochdoublee_HJD[0.0001/0.003] Error on HJDdstat.error;time.epochdoubleE[-29027/2590] Eclipsing time (1)time.epochdoubleO-C[-0.04/0.06] Computed O-C valuedstat.fit.residualdoubleRes[-0.02/0.008] Residualdstat.fit.residualdoubleRef[1/5] Reference used (2)meta.ref;instr.setupint