J/AJ/147/36ivo://CDS.VizieR/J/AJ/147/36doi:10.26093/cds/vizier.51470036CDSTorres G.Vaz L.P.R.Lacy C.H.S.Claret A.2017-07-10T06:22:08Z2014-09-19T08:57:55ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsradial-velocityvisible-astronomybroad-band-photometryWe report differential photometric observations and radial-velocity measurements of the detached, 1.69 day period, double-lined eclipsing binary AQ Ser. Accurate masses and radii for the components are determined to better than 1.8% and 1.1%, respectively, and are M_1_=1.417+/-0.021M_{sun}_, M_2_=1.346+/-0.024M_{sun}_, R_1_=2.451+/-0.027R_{sun}_, and R_2_=2.281+/-0.014R_{sun}_. The temperatures are 6340+/-100K (spectral type F6) and 6430+/-100K (F5), respectively. Both stars are considerably evolved, such that predictions from stellar evolution theory are particularly sensitive to the degree of extra mixing above the convective core (overshoot). The component masses are different enough to exclude a location in the H-R diagram past the point of central hydrogen exhaustion, which implies the need for extra mixing. Moreover, we find that current main-sequence models are unable to match the observed properties at a single age even when allowing the unknown metallicity, mixing length parameter, and convective overshooting parameter to vary freely and independently for the two components. The age of the more massive star appears systematically younger. AQ Ser and other similarly evolved eclipsing binaries showing the same discrepancy highlight an outstanding and largely overlooked problem with the description of overshooting in current stellar theory.2014AJ....147...36Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/147/36CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/128 : Chromospherically Active Binaries. Third version (Eker+, 2008)B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)J/AJ/147/1 : Spectroscopy and photometry of HP Aur (Lacy+, 2014)J/AJ/143/129 : BF Dra photometric & spectroscopic observations (Lacy+, 2012)J/AJ/139/2347 : CO And Vr light curves and RV curve (Lacy+, 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/147/36https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/147/36http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/147/36https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/147/36https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/147/36http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/147/36GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/147/36/table1Differential V-band measurements of AQ Ser from the the URSA WebScope (at Kimpel Observatory, Arkansas)DVmagDifferential V band magnitudemagphot.mag;em.opt.V;arith.difffloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date (HJD-2400000)dtime.epochdoublePhase[0/1] Orbital phase (G1)time.phasefloatJ/AJ/147/36/table2Differential V-band measurements of AQ Ser from the NFO WebScope (near Silver City, New Mexico)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date (HJD-2400000)dtime.epochdoublePhase[0/1] Orbital phase (G1)time.phasefloatDVmagDifferential V band magnitudemagphot.mag;em.opt.V;arith.difffloatJ/AJ/147/36/table3Heliocentric radial velocities for AQ SerrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date (HJD-2400000)dtime.epochdoublePhase[0/1] Orbital phase (G1)time.phasefloatRV1Primary radial velocitykm/sspect.dopplerVelocfloate_RV1Error in RA1km/sstat.errorfloatRV2Secondary radial velocitykm/sspect.dopplerVelocfloate_RV2Error in RA2km/sstat.errorfloatO-C1Primary (O-C) residualkm/sstat.fit.residual;stat.fit.omcfloatO-C2Secondary (O-C) residualkm/sstat.fit.residual;stat.fit.omcfloatJ/AJ/147/36/table5Eclipse timing measurements for AQ SerrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date (HJD-2400000)dtime.epochdoublee_HJDUncertainty in HJD (1)dstat.error;time.epochdoubleTypeEclipse type (primary or secondary) (2)meta.notecharSrcSource of the measurement (3)meta.ref;pos.framecharO-CResidual (4)dstat.fit.residualfloat