J/AJ/129/1001ivo://CDS.VizieR/J/AJ/129/1001doi:10.26093/cds/vizier.51291001CDSFekel F.C.Barlow D.J.Scarfe C.D.Jancart S.Pourbaix D.2017-06-01T08:52:15Z2016-10-04T06:41:55ZCDS support team

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

cds-question@unistra.frspectroscopic-binary-starsradial-velocityWe have obtained extensive spectroscopic and velocity spectrometer observations of HD166181, a previously known single-lined spectroscopic binary. Our improved orbit for the G6 V primary has a period of 1.8098343days and is circular. Although the lines of additional components have not been detected, radial velocity measurements confirm that the system has additional velocity variations with a period of 2092days, or 5.73yr. This long-period orbit has an eccentricity of 0.76. An analysis of the Hipparcos observations produces a well-determined astrometric orbit for the long-period system that has an inclination of 78{deg}. Mass estimates of the components in this zero-age main-sequence multiple system indicate that the unseen secondary in the 5.73yr orbit may also be a binary. Thus, HD 166181 is at least a triple system and possibly quadruple.2005AJ....129.1001Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/129/1001CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/362/223 : 1984-1998 BV photometry of V815 Her (Jetsu+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/129/1001https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/129/1001http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/129/1001https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/129/1001https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/129/1001http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/129/1001GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/129/1001/table1Radial velocities of HD 166181SPhase[0/1] Phase in the short-period orbit ({Phi}_S_)time.phasefloatRV[-70.7/57.2] Radial velocitykm/sphys.veloc;pos.heliocentricfloatw_RV[0/1] Weight of RVstat.weightfloatf_RV[a] Flag on RV (a=lithium region) (1)meta.codecharO-C[-15.9/15.7] The radial velocity residualkm/sstat.fit.residual;spect.dopplerVelocfloatObsObservatory code (DDO, DAO, OHP, or KPNO) (2)meta.code;instr.obstycharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Datedtime.epochdoubleDelT[-0.001/0.015] Light time correctiondtime.epochfloatLPhase[0/1] Phase in the long-period orbit ({Phi}_L_)time.phasefloat