J/ApJ/809/159ivo://CDS.VizieR/J/ApJ/809/159doi:10.26093/cds/vizier.18090159CDSRoettenbacher R.M.Monnier J.D.Fekel F.C.Henry G.W.Korhonen H.,Latham D.W.Muterspaugh M.W.Williamson M.H.Baron F.,ten Brummelaar T.A.Che X.Harmon R.O.Schaefer G.H.Scott N.J.,Sturmann J.Sturmann L.Turner N.H.2017-06-26T11:49:44Z2016-01-14T15:21:34ZCDS support team

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

cds-question@unistra.frmultiple-starsradial-velocityinterferometryvisible-astronomyWide-band photometryTo measure the stellar and orbital properties of the metal-poor RS CVn binary o Draconis (o Dra), we directly detect the companion using interferometric observations obtained with the Michigan InfraRed Combiner at Georgia State University's Center for High Angular Resolution Astronomy (CHARA) Array. The H-band flux ratio between the primary and secondary stars is the highest confirmed flux ratio (370+/-40) observed with long-baseline optical interferometry. These detections are combined with radial velocity data of both the primary and secondary stars, including new data obtained with the Tillinghast Reflector Echelle Spectrograph on the Tillinghast Reflector at the Fred Lawrence Whipple Observatory and the 2m Tennessee State University Automated Spectroscopic Telescope at Fairborn Observatory. We determine an orbit from which we find model-independent masses and ages of the components (M_A_=1.35+/-0.05M_{sun}_, M_B_=0.99+/-0.02M_{sun}_, system age =3.0+-0.5Gyr). An average of a 23-year light curve of o Dra from the Tennessee State University Automated Photometric Telescope folded over the orbital period newly reveals eclipses and the quasi-sinusoidal signature of ellipsoidal variations. The modeled light curve for our system's stellar and orbital parameters confirm these ellipsoidal variations due to the primary star partially filling its Roche lobe potential, suggesting most of the photometric variations are not due to stellar activity (starspots). Measuring gravity darkening from the average light curve gives a best-fit of {beta}=0.07+/-0.03, a value consistent with conventional theory for convective envelope stars. The primary star also exhibits an anomalously short rotation period, which, when taken with other system parameters, suggests the star likely engulfed a low-mass companion that had recently spun-up the star.2015ApJ...809..159Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/809/159CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/pastel : The PASTEL catalogue (Soubiran+, 2010-)I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)J/ApJ/807/23 : RS CVn primaries. I. sig Gem (Roettenbacher+, 2015)J/A+A/579/A68 : CANDID code for interferometric obs. (Gallenne+, 2015)J/AJ/149/63 : Radial velocities of HD54371, HR 2692 & 16 UMa (Fekel+, 2015)J/A+A/553/A95 : PCA approach to effective temperatures (Bermejo+, 2013)J/A+A/547/A91 : Spectroscopic analysis of 348 red giants (Zielinski+, 2012)J/MNRAS/427/343 : Infrared excesses of Hipparcos stars (McDonald+, 2012)J/ApJ/746/101 : Diameters and temperatures of AFG stars (Boyajian+, 2012)J/ApJS/190/203 : 3.6 years of DIRBE NIR stellar light curves (Price+, 2010)J/other/A+ARV/17.251 : Stars observed with Doppler imaging (Strassmeier, 2009)J/AJ/135/209 : Rotational & radial vel. of HIP giants (Massarotti+, 2008)J/AJ/130/794 : Radial velocities & BV photometry of HD 144110 (Fekel+, 2005)J/A+A/430/165 : Radial velocities for 6691 K and M giants (Famaey+, 2005)J/AJ/128/3012 : Speckle interferometry at USNO. X. (Mason+, 2004)J/ApJ/578/943 : vsini of binaries with evolved component (de Medeiros+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/809/159https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/809/159http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/809/159https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/809/159https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/809/159http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/809/159GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/809/159/table3Radial velocity data of o Draconis (AST/TSU)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[54384.7/57134] Heliocentric Julian Date; HJD-2400000time.epochdoubleRV1[-43.1/3.8] Primary star radial velocity (1)km/sspect.dopplerVelocfloatRV2[-54/10.9]? Secondary star radial velocity (1)km/sspect.dopplerVelocfloatnullableJ/ApJ/809/159/table2Radial velocity data of o Draconis (Wyeth & Tillinghast/CfA)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[53249.7/56210.6] Heliocentric Julian Date; HJD-2400000time.epochdoubleRV1[-42.7/4.1] Primary star radial velocity (1)km/sspect.dopplerVelocfloatJ/ApJ/809/159/table4Johnson B and V differential magnitudes of o Draconis (APT/TSU)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[48705.9/57156] Heliocentric Julian Date; HJD-2400000time.epochdoubleVarB[-1.2/-1]? B mag diff: o Dra - HD175511 (1)magphot.mag;arith.difffloatnullableVarV[-2.4/-2.2]? V mag diff: o Dra - HD175511 (1)magphot.mag;arith.difffloatnullableChkB[-0.2/0]? B mag diff: 48 Dra - HD175511 (1)magphot.mag;arith.difffloatnullableChkV[-1.4/-1.2]? V mag diff: 48 Dra - HD175511 (1)magphot.mag;arith.difffloatnullable