J/MNRAS/381/602ivo://CDS.VizieR/J/MNRAS/381/602doi:10.26093/cds/vizier.73810602CDSYuan J.Qian S.2024-07-05T20:15:38Z2008-12-17T12:01:27ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsvisible-astronomybroad-band-photometryWe present two new sets of complete light curves of EQ Tauri (EQ Tau) observed in 2000 October and 2004 December. These were analysed, together with the light curves obtained by Yang & Liu (2002AJ....124.3358Y) in 2001 December, with the 2003 version of the Wilson-Devinney code. In the three observing seasons, the light curves show a noticeable variation in the time-scale of years. The more massive component of EQ Tau is a solar-type star (G2) with a very deep convective envelope, which rotates about 80 times as fast as the Sun. Therefore, the change can be explained by dark-spot activity on the common convective envelope. The assumed unperturbed part of the light curve and the radial velocities published by Rucinski et al. (2001AJ....122.1974R) were used to determine the basic parameters of the system, which were kept fixed for spot modelling in the three sets of light curves. The results reveal that the total spotted area on the more massive component covers 18, 3 and 20 per cent of the photospheric surface in the three observing seasons, respectively. Polar spots and high-latitude spots are found. The analysis of the orbital period has demonstrated that it undergoes cyclical oscillation, which is due to either a tertiary component or periodic magnetic activity in the more massive component.2007MNRAS.381..602Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/381/602CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/132/960 : V(RI)c light-curves of EQ Tauri (Hrivnak+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/381/602https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/381/602http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/381/602https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/381/602https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/381/602http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/381/602GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/MNRAS/381/602/table1CCD photometric data of EQ Tau in the B band observed on 2000 October 30 and 31, and 2004 December 11, 12 and 18recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian datedtime.epochdoubleDmagDifferential magnitude in B or V bandmagphot.mag;em.opt.BfloatJ/MNRAS/381/602/table2CCD photometric data of EQ Tau in the V band observed on 2000 October 30 and 31, and 2004 December 11, 12, 18, and 21recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian datedtime.epochdoubleDmagDifferential magnitude in B or V bandmagphot.mag;em.opt.BfloatJ/MNRAS/381/602/table4Time of light minimum for EQ TaurirecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian datedtime.epochdoublen_HJD[a] Partial coverage (1)meta.notecharMin[I II] First (I) or second (II) minimummeta.notecharMethodMethod used (pg, pe, sp or CCD)meta.code;obscharEEphemerisdtime.phasedoubleO-CO-C valuestat.fit.residualfloatResResidualsstat.fit.residualfloatRefReferences, in refs.dat filemeta.ref;meta.fileintJ/MNRAS/381/602/refsReferencesRefReference numbermeta.id;meta.mainintprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBibCodeBibCodemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharComCommentsmeta.notechar