J/AJ/154/195ivo://CDS.VizieR/J/AJ/154/195doi:10.26093/cds/vizier.51540195CDSBriceno C.Tokovinin A.2018-09-28T08:44:09Z2018-08-02T13:52:42ZCDS support team

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

cds-question@unistra.fropen-star-clustersmultiple-starsinfrared-photometryvisible-astronomyphotometrystellar-distancestellar-spectral-typespre-main-sequence-starsWe present Adaptive Optics-aided speckle observations of 47 young stars in the {epsilon} Cha association made at the 4 m Southern Astrophysical Research Telescope in the I-band. We resolved 10 new binary pairs, 5 previously known binaries, and 2 triple systems, also previously known. In the separation range between 4 and 300 au, the 30 association members of spectral types G0 and later host 6 binary companions, leading to the raw companion frequency of 0.010+/-0.04 per decade of separation, comparable to the main sequence dwarfs in the field. On the other hand, all five massive association members of spectral types A and B have companions in this range. We discuss the newly resolved and known binaries in our sample. Observed motions in the triple system {epsilon} Cha, composed of three similar B9V stars, can be described by tentative orbits with periods 13 and ~900 years and a large mutual inclination.2017AJ....154..195Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/154/195CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/239 : The Hipparcos and Tycho Catalogues (ESA 1997)B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)I/337 : Gaia DR1 (Gaia Collaboration, 2016)J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)J/MNRAS/435/1325 : Membership of the {epsilon} Cha association (Murphy+, 2013)J/AJ/150/50 : Speckle interferometry at SOAR in 2014 (Tokovinin+, 2015)J/AJ/151/153 : Speckle interferometry at SOAR in 2015 (Tokovinin+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/154/195https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/154/195http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/154/195https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/154/195https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/154/195http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/154/195GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/154/195/table1 (Targets Observed in the epsilon Cha Stellar Group)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/195/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/195/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/195/table1?GETtext/xml+votable180.050000true142.087917-78.2597220.005555555555555556Cone search capability for table J/AJ/154/195/table2 (Measurements of Resolved Multiples in epsilon Cha)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/195/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/195/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/195/table2?GETtext/xml+votable180.050000true167.0058225-77.70793860.0055555555555555566/36884 36946 36947 36948 36949 36956 36969 37120 37121 37122 37125 37137 37138 37173 41122 41128 41130 41135 41472 41474 41484 41505 41526 41528 41600 416012.367228618189496e-19 2.6706780932288093e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/154/195?format=asciiInfraredOpticaldefaultJ/AJ/154/195/table1Targets Observed in the epsilon Cha Stellar GroupSimbadNameSimbad column added by the CDSmeta.idcharDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainf_Sep[*T] Flag on separation (3)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharMembDesignation from Murphy et al. (2013, J/MNRAS/435/1325) (1)meta.idcharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainImag[5.39/14.0] Cousins I-band magnitudemagphot.mag;em.opt.IfloatSpTypeMK spectral typesrc.spTypecharDist1[90/477]? Distance from Gaia DR1 parallax (Cat. I/337)pcpos.distance;pos.heliocentricintnullablee_Dist1[5/157]? Uncertainty in Dist1pcstat.errorintnullableDist2[94/165]? Distance from Murphy et al. (2013, J/MNRAS/435/1325)pcpos.distance;pos.heliocentricintnullabler_Dist2[H] Reference for Dist2 (2)meta.ref;pos.framecharSep[0.03/4.2]? Separation between componentsarcsecpos.angDistancefloatnullableJ/AJ/154/195/table2Measurements of Resolved Multiples in epsilon ChaSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWDSWashington Double Star catalog designation (HHMMm+DDMM)meta.id;meta.maincharNameStar name (1)meta.idcharEpoch[16.0474/17.3719] Besselian epoch of observation (minus 2000)yrtime.epoch;obsfloatFilter[Iy] Filter usedinstr.setup;instr.filterchartheta[5.5/311.3] Position angle {theta}degpos.posAngfloatrho[0.0306/4.2409] Separation {rho}arcsecpos.angDistancefloatDm[0/5.7] Magnitude difference {Delta}m between componentsmagphot.mag;arith.difffloatf_Dm[*:q] Flag on Dm (2)meta.codecharNoteShort notemeta.notechar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullableJ/AJ/154/195/table3Detection Limits for Unresolved TargetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget namemeta.id;meta.maincharrho(min)[0.04/0.1] Minimum separation {rho}_min_ (1)arcsecpos.angDistancefloatDm(0.15)[0.7/2.6] Magnitude difference for 0.15 arcsec separation (2)magpos.angDistance;arith.difffloatDm(1)[2.2/6.1] Magnitude difference for 1 arcsec separation (2)magpos.angDistance;arith.difffloat