J/ApJ/810/157ivo://CDS.VizieR/J/ApJ/810/157doi:10.26093/cds/vizier.18100157CDSVaccaro T.R.Wilson R.E.Van Hamme W.Terrell D.2017-06-12T08:25:08Z2016-01-19T08:15:28ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsradial-velocityinfrared-photometryvisible-astronomybroad-band-photometryV471 Tauri, a white dwarf-red dwarf eclipsing binary (EB) in the Hyades, is well known for stimulating development of common envelope theory, whereby novae and other cataclysmic variables form from much wider binaries by catastrophic orbit shrinkage. Our evaluation of a recent imaging search that reported negative results for a much postulated third body shows that the object could have escaped detection or may have actually been seen. The balance of evidence continues to favor a brown dwarf companion about 12 AU from the EB. A recently developed algorithm finds unified solutions from three data types. New radial velocities (RVs) of the red dwarf and BVRcIc light curves are solved simultaneously along with white dwarf and red dwarf RVs from the literature, uvby data, the Microvariability and Oscillations of Stars mission light curve, and 40 years of eclipse timings. Precision-based weighting is the key to proper information balance among the various data sets. Timewise variation of modeled starspots allows unified solution of multiple data eras. Light-curve amplitudes strongly suggest decreasing spottedness from 1976 to about 1980, followed by approximately constant spot coverage from 1981 to 2005. An explanation is proposed for lack of noticeable variation in 1981 light curves, in terms of competition between spot and tidal variations. Photometric-spectroscopic distance is estimated. The red dwarf mass comes out larger than normal for a K2 V star, and even larger than adopted in several structure and evolution papers. An identified cause for this result is that much improved red dwarf RV curves now exist.2015ApJ...810..157Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/810/157CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)B/sb9 : 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)J/A+A/559/A43 : Pan-STARRS1 (PS1) observations of the Hyades (Goldman+, 2013)J/ApJS/187/149 : StarCAT: STIS UV echelle spectra of stars (Ayres, 2010)J/other/A+ARV/17.251 : Stars observed with Doppler imaging (Strassmeier, 2009)J/other/IBVS/5802 : Minima and maxima of 735 variables (Hubscher+, 2007)J/AJ/134/2353 : Observations of contact binaries (Rucinski+, 2007)J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)J/A+A/446/785 : Catalogue of eclipsing variables (Malkov+, 2006)J/AcA/54/207 : Ephemerids of eclipsing binaries (Kreiner, 2004)J/MNRAS/349/1069 : Chromospherically active binaries (Karatas+, 2004)J/A+A/381/446 : Astrometric Radial Velocities. III. (Madsen+, 2002)J/A+A/367/111 : A Hipparcos study of the Hyades cluster (de Bruijne+, 2001)J/A+A/281/811 : Long-term variations in V471 Tau (Ibanoglu+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/810/157https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/810/157http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/810/157https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/810/157https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/810/157http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/810/157GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfraredOpticaldefaultJ/ApJ/810/157/table1Red dwarf 1998 radial velocities (RVs)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Datedtime.epochdoubleHJEDHeliocentric Julian Ephemeris Datedtime.epoch;pos.heliocentricdoubleRV[-122/187] Radial Velocitykm/sphys.veloc;pos.heliocentricfloate_RV[1/5] Individual RV standard errorkm/sstat.errorfloatJ/ApJ/810/157/table2B, V, R_c_, I_c_ 1998 light curves (LCs)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD(B)B band Heliocentric Julian Datedtime.epochdoubleHJED(B)B band Heliocentric Julian Ephemeris Date (1)dtime.epochdoubledBmag[-0.5/-0.2] Differential B magnitude (2)magphot.mag;em.opt.B;arith.difffloatHJD(V)V band Heliocentric Julian Datedtime.epochdoubleHJED(V)V band Heliocentric Julian Ephemeris Date (1)dpos.cartesian.ydoubledVmag[-0.2/0.02]? Differential V magnitude (2)magphot.mag;em.opt.V;arith.difffloatnullableHJD(R)R_c_ band Heliocentric Julian Datedtime.epochdoubleHJED(R)R_c_ band Heliocentric Julian Ephemeris Date (1)dtime.epoch;pos.heliocentricdoubledRmag[0.05/0.2]? Differential R_c_ magnitude (2)magphot.mag;arith.difffloatnullableHJD(I)I_c_ band Heliocentric Julian Datedtime.epochdoubleHJED(I)I_c_ band Heliocentric Julian Ephemeris Date (1)dtime.epoch;pos.heliocentricdoubledImag[0.3/0.5]? Differential I_c_ magnitude (2)magphot.mag;arith.difffloatnullable