J/other/NewA/37.ivo://CDS.VizieR/J/other/NewA/37.48CDSYang Y.Zhang L.Dai H.Li H.2015-09-17T08:58:22Z2015-08-24T15:10:04ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsphotometryWe present new photometry of the eclipsing binary ZZ Cyg. From all accumulated eclipsing times, we constructed the (O-C) curve, which can be described by a downward parabola with a possible light-time orbit. The period decrease rate is source dP/dt=-5.73(+/-0.18)d/yr. The modulated period, semi-amplitude and eccentricity for the light-time orbit are Pmod=71.4(+/-1.1)yr, A=0.0071(+/-0.0005)day and e=0.420(+/-0.053), respectively. After removing effects of the magnetic activity, this kind of cyclic oscillation may be attributed to light-time effect via an additional companion. By using the W-D code, the photometric model was updated, which identified that ZZ Cyg is a near-contact binary. We find that a hot spot may occur on the primary that explains the asymmetric light curve. The secular period decrease may possibly cause the fill-out factor of the primary to increase. Finally it will finally fill its Roche lobe. This kind of binary, ZZ Cyg, may evolve into contact binary star.2015NewA...37...48Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/other/NewA/37.48CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/other/NewA/37.48https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/other/NewA/37.48http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/other/NewA/37.48https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/other/NewA/37.48https://vizier.iucaa.in/viz-bin/votable?-source=J/other/NewA/37.48http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/other/NewA/37.48GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/other/NewA/37.48/table2All compiled light minimum times of ZZ CygrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Datedtime.epochdoubleEpoch[-47692/18349.5] Epoch (cycle)meta.number;time.perioddoubleMethodObservational method used: vi=visual, pg=photographic, pe=photoeletric, or CCDinstr.setupcharMin[I II] Minimum typemeta.codenullable(O-C)1[-0.06/0.03] Eclipse time residual of the linear fitdstat.fit.residualfloat(O-C)2[-0.03/0.03] Eclipse time residual of the parabolic fitdstat.fit.residualfloat