J/AJ/157/207ivo://CDS.VizieR/J/AJ/157/207doi:10.26093/cds/vizier.51570207CDSLiao W.-P.Qian S.-B.Sarotsakulchai T.2019-11-22T14:59:30Z2019-08-14T07:31:18ZCDS support team

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

cds-question@unistra.frmultiple-starseclipsing-binary-starsinfrared-photometryvisible-astronomybroad-band-photometryVZ Lib is a southern triple-lined system. By analyzing all available times of light minima, orbital period changes are revisited in detail. We discovered that the observed-calculated (O-C) curve shows a long-term period decrease at a rate of dP/dt=-2.25x10^-7^ days/yr, revealing a mass transfer from the more massive component to the less massive one. A cyclic variation covering more than three cycles was discovered, which was analyzed for the light-travel-time effect via the presence of the tertiary companion. The cyclic variation has a short period of 2.96 (+/-0.04) yr and a small semiamplitude of 0.0039 (+/-0.0004) days. The mass of the third body was determined to be M_3_sini_3_=0.52 (+/-0.07) M_{sun}_ and an orbital semimajor axis shorter than 1.93 (+/-0.31) au was obtained. Orbital properties of this close-in companion should provide valuable information on the formation of close binaries and stellar dynamical interaction. New complete BVR_c_I_c_ light curves of VZ Lib were obtained and modeled with the Wilson-Devinney code. The light curves show a small but significant O'Connell effect that was not detectable in 1981 and 2007 but in 2004, so we derived a new photometric solution with assuming spot and a third light in the system. It is found that the light-curve subtype changed from A-type to W-type, which was possibly caused by a dark spot on the massive component. Our photometric solutions are in agreement with the spectroscopic results given by previous authors.2019AJ....157..207Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/157/207CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)J/A+A/465/943 : BVI and RV curves of 5 eclipsing binaries (Szalai+, 2007)J/AJ/134/2353 : Observations of contact binaries (Rucinski+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/157/207https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/157/207http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/157/207https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/157/207https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/157/207http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/157/207GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/157/207/table2Light curve observations for VZ LibrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFilt[B V Rc Ic] Light curve filtermeta.notecharHJD[2458250.1413/2458256.2813] Heliocentric Julian Datedtime.epochdoubleDmag[-2.975/-1.971] Differential magnitude in Filtmagphot.mag;arith.difffloatJ/AJ/157/207/table3A total of 98 times of light minima for VZ LibrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[2428731.308/2458256.16677] Heliocentric Julian Date of light minimumdtime.epochdoublee_HJD[0.0001/0.003]? Uncertainty in HJDdstat.error;time.epochdoublenullableMethObservational method (1)stat.fitcharRef[1/24] Reference (2)meta.ref;pos.frameint