J/AJ/144/149ivo://CDS.VizieR/J/AJ/144/149doi:10.26093/cds/vizier.51440149CDSChristopoulou P.-E.Papageorgiou A.Vasileiadis T.Tsantilas S.2017-06-29T08:55:46Z2013-12-18T12:38:42ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsccd-photometryinfrared-photometryvisible-astronomybroad-band-photometryNew CCD four-color light curves of TY Boo made on eight nights over 2010-2011 were analyzed in comparison with historical light curves obtained from 1969 through 2011. The light curves could all be represented by a unique geometry and by wavelength consistent photometric parameters of a two-spot model on either stellar component. It is confirmed that TY Boo is a shallow W-type contact binary system with a degree of contact factor of f=7.6%(+/-0.8). A period investigation based on all available data shows a long-term decrease (dP/dt=-3.65x10^-8^days/yr) and an oscillation (P_3_=58.9yr, A=0.0254days). Without ruling out the presence of a tertiary companion, the weight of evidence points to an active cyclic magnetic activity that causes spot formation rather than an unseen companion. Mass transfer between the components and angular momentum loss are also considered as possible mechanisms.2012AJ....144..149Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/144/149CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2013)J/AN/334/860 : Catalogue of eclipsing variables. Ver. 2 (Avvakumova+, 2013)J/AJ/143/99 : Photometry of W UMa eclipsing binaries (Terrell+, 2012)J/AJ/143/30 : CCD photometry of V380 Cas (Christopoulou+, 2012)J/AJ/142/99 : BVRI observations of TZ Boo (Christopoulou+, 2011)J/AJ/134/179 : Ligth minimum times of TY Boo (Yang+, 2007)J/A+A/446/785 : Catalogue of eclipsing variables (Malkov+, 2006)J/AJ/131/621 : A catalog of 1022 bright contact binary stars (Gettel+, 2006)J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)J/AcA/54/207 : Ephemerids of eclipsing binaries (Kreiner, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/144/149https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/144/149http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/144/149https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/144/149https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/144/149http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/144/149GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/144/149/table2BVR_c_I_c_ observational data for the eclipsing binary TY BoorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFlt[BVRI] Filter used in the observation among B, V, R=R_c_, I=I_c_instr.setup;obscharHJDHeliocentric Julian Date of the observationdtime.epochdoubleDmagDifferential magnitude in Fltmagphot.mag;arith.difffloatJ/AJ/144/149/table4Added times of minimum for TY Boo (2006-2011)EEpoch (cycle number)meta.number;time.periodfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date of minimum lightdtime.epochdoubleMethDetection method (ccd, pe=photoelectric)meta.code;obscharType[PS] Type of minimum (P=primary, S=secondary)meta.codecharO-CThe O-C value of the new minima (1)dstat.fit.residualdoubleResResidual from Eq.(4) (2)dstat.fit.residualdoubleObsObserverobs.observercharRefReference; in refs.dat filemeta.ref;pos.frameintJ/AJ/144/149/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference identifierpos.framecharBibCodeBibliographic codemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharComCommentsmeta.notechar