J/ApJ/682/L117ivo://CDS.VizieR/J/ApJ/682/L117doi:10.26093/cds/vizier.16829117CDSGies D.R.Dieterich S.Richardson N.D.Riedel A.R.Team B.L.,McAlister H.A.Bagnuolo W.G.JrGrundstrom E.D.Stefl S.Rivinius T.,Baade D.2017-07-06T06:25:43Z2010-11-23T12:31:23ZCDS support team

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

cds-question@unistra.frspectroscopic-binary-starsb-starsradial-velocityWe present a radial velocity study of the rapidly rotating B star Regulus that indicates the star is a single-lined spectroscopic binary. The orbital period (40.11 days) and probable semimajor axis (0.35AU) are large enough that the system is not interacting at present. However, the mass function suggests that the secondary has a low mass (M_2_>0.30M_{sun}_), and we argue that the companion may be a white dwarf. Such a star would be the remnant of a former mass donor that was the source of the large spin angular momentum of Regulus itself.2008ApJ...682L.117Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/682/L117CatalogResearchIsServedByTAP VizieR generic servicerelated-toIII/252 : Pulkovo radial velocities for 35493 HIP stars (Gontcharov, 2006)III/190 : WEB Catalog of Radial Velocities (Duflot+ 1995)J/MNRAS/389/869 : Multiplicity among bright stellar systems (Eggleton+, 2008)J/AJ/133/889 : Faint companions of Hipparcos stars (Lepine+, 2007)J/ApJ/663/960 : Radial velocities of Leo I stars (Sohn+, 2007)J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)J/A+A/379/162 : Binaries with post-T Tauri secondaries (Gerbaldi+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/682/L117https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/682/L117http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/682/L117https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/682/L117https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/682/L117http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/682/L117GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/682/L117/table1Journal of spectroscopyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRunning sequence numbermeta.id;meta.mainintprimaryDate1Date of observation in Besselian year (first)yrtime.epochfloatDate2? Date of last observation in Besselian yearyrtime.epochfloatnullableRangeRange in Angstrom0.1nminstr.filter;em.wl.centralcharPowerResolving power ({lambda}/{Delta}{lambda})spect.resolutionintNspNumber of observed spectrameta.numberintTelObservatory/Telescope/Spectrographmeta.notecharJ/ApJ/682/L117/table2Radial velocity measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateHJDdtime.epochdoublePhaseOrbital phase from ascending nodetime.phasefloatHRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRVMean error on HRVkm/sstat.errorfloatO-CObserved minus calculated residualkm/sstat.fit.residual;stat.fit.omcfloatSeqRunning sequence number from Table 1meta.id;meta.mainint