J/ApJ/851/132ivo://CDS.VizieR/J/ApJ/851/132doi:10.26093/cds/vizier.18510132CDSCzekala I.Andrews S.M.Torres G.Rodriguez J.E.Jensen E.L.N.,Stassun K.G.Latham D.W.Wilner D.J.Gully-Santiago M.A.Grankin K.N.,Lund M.B.Kuhn R.B.Stevens D.J.Siverd R.J.James D.Gaudi B.S.,Shappee B.J.Holoien T.W.-S.2018-10-22T13:16:28Z2018-09-10T14:15:03ZCDS support team

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

cds-question@unistra.frmultiple-starsvisible-astronomyspectroscopyradial-velocityinfrared-photometryphotometryWe present spatially and spectrally resolved Atacama Large Millimeter/submillimeter Array (ALMA) observations of gas and dust orbiting the pre-main-sequence hierarchical triple-star system GW Ori. A forward modeling of the ^13^CO and C^18^O J=2-1 transitions permits a measurement of the total stellar mass in this system, 5.29+/-0.09M_{sun}_, and the circumtriple disk inclination, 137.6{deg}+/-2.0{deg}. Optical spectra spanning a 35yr period were used to derive new radial velocities and, coupled with a spectroscopic disentangling technique, revealed that the A and B components of GW Ori form a double-lined spectroscopic binary with a period of 241.50+/-0.05d; a tertiary companion orbits that inner pair with a period of 4218+/-50d. Combining the results from the ALMA data and the optical spectra with three epochs of astrometry in the literature, we constrain the individual stellar masses in the system (M_A_~2.7M_{sun}_, M_B_~1.7M_{sun}_, M_C_~0.9M_{sun}_) and find strong evidence that at least one of the stellar orbital planes (and likely both) is misaligned with the disk plane by as much as 45{deg}. A V-band light curve spanning 30yr reveals several new ~30-day eclipse events 0.1-0.7mag in depth and a 0.2mag sinusoidal oscillation that is clearly phased with the AB-C orbital period. Taken together, these features suggest that the A-B pair may be partially obscured by material in the inner disk as the pair approaches apoastron in the hierarchical orbit. Lastly, we conclude that stellar evolutionary models are consistent with our measurements of the masses and basic photospheric properties if the GW Ori system is ~1Myr old.2017ApJ...851..132Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/851/132CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)B/eso : ESO Science Archive Catalog (ESO, 1991-2018)VI/110 : Final Merged Log of IUE Observations (NASA-ESA, 2000)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+AS/124/75 : Multiple star catalogue (MSC) (Tokovinin 1997-1999)J/AJ/118/1043 : Herbig Ae/Be stars catalog (Herbst+, 1999)J/AJ/121/2124 : {lambda} Ori pre-main-sequence stars photom. (Dolan+, 2001)J/AJ/123/387 : {lambda} Ori star-forming region VRI photom. (Dolan+, 2002)J/ApJS/147/305 : IUE atlas of pre-main-sequence stars (Valenti+, 2003)J/A+A/461/183 : Variability of classical T Tauri (Grankin+, 2007)J/MNRAS/389/869 : Multiplicity among bright stellar systems (Eggleton+, 2008)J/ApJ/720/1118 : i-band photometry of HAT-P-16 (Buchhave+, 2010)J/ApJ/744/121 : Far-UV spectroscopy of T Tau stars (Yang+, 2012)J/ApJ/761/123 : KELT-1 photometry and spectroscopy follow-up (Siverd+, 2012)J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/AJ/151/146 : IRS sp. with features of crystalline silicates (Chen+, 2016)J/ApJ/834/142 : Gould's Belt Distances Survey (GOBELINS) II. (Kounkel+, 2017)J/ApJ/844/103 : Orbit alignment in triple stars (Tokovinin, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/851/132https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/851/132http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/851/132https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/851/132https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/851/132http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/851/132GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap3.322582951404819e-19 3.852589004194616e-19InfraredOpticaldefaultJ/ApJ/851/132/table3Photometric measurements of GW OriTelTelescope used in the observation (1)instr.setup;obscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[47031.4/57829.8] Heliocentric Julian Date; HJD-2400000dtime.epochdoubleVmag[9.4/30] Apparent V band magnitudemagphot.mag;em.opt.Vfloate_Vmag[0.001/0.2]? The 1{sigma} uncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatnullableJ/ApJ/851/132/table2Heliocentric RV measurements of GW OrirecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[44919/57863.7] Heliocentric Julian Date; HJD-2400000 (1)dtime.epochdoubleRVelA[12/39.5] Radial velocity of primarykm/sphys.veloc;pos.heliocentricfloate_RVelA[0.4/11] The 1{sigma} uncertainty in RVelAkm/sstat.errorfloatRVelB[-10/50] Radial velocity of secondarykm/sphys.veloc;pos.heliocentricfloate_RVelB[1/38] The 1{sigma} uncertainty in RVelBkm/sstat.errorfloat