J/MNRAS/447/1267ivo://CDS.VizieR/J/MNRAS/447/1267doi:10.26093/cds/vizier.74471267CDSMurphy S.J.Lawson W.A.2024-08-14T20:19:32Z2015-01-15T16:20:07ZCDS support team

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

cds-question@unistra.frstellar-associationspre-main-sequence-starsstellar-spectral-typesradial-velocityproper-motionsstellar-distanceThe Octans association is one of several young stellar moving groups recently discovered in the Solar neighbourhood and hence a valuable laboratory for studies of stellar, circumstellar disc and planetary evolution. However, a lack of low-mass members or any members with trigonometric parallaxes means the age, distance and space motion of the group are poorly constrained. To better determine its membership and age, we present the first spectroscopic survey for new K- and M-type Octans members, resulting in the discovery of 29 UV-bright K5-M4 stars with kinematics, photometry and distances consistent with existing members. Nine new members possess strong LiI 6708 absorption, which allow us to estimate a lithium age of 30-40Myr, similar to that of the Tucana-Horologium association and bracketed by the firm lithium depletion boundary ages of the beta Pictoris (20Myr) and Argus/IC 2391 (50Myr) associations. Several stars also show hints in our medium-resolution spectra of fast rotation or spectroscopic binarity. More so than other nearby associations, Octans is much larger than its age and internal velocity dispersion imply. It may be the dispersing remnant of a sparse, extended structure which includes some younger members of the foreground Octans-Near association recently proposed by Zuckerman and collaborators.2015MNRAS.447.1267Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/447/1267CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/447/1267https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/447/1267http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/447/1267https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/447/1267https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/447/1267http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/447/1267GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/447/1267/table1 (Spectroscopy of Octans candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/447/1267/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/447/1267/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/447/1267/table1?GETtext/xml+votable180.050000true83.068125-41.54572220.005555555555555556Cone search capability for table J/MNRAS/447/1267/table2 (Previously proposed Octans members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/447/1267/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/447/1267/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/447/1267/table2?GETtext/xml+votable180.050000true62.9819475-58.02982940.0055555555555555566/20528 20564 20696 20715 21070 32790 32897 33032 33050 33057 33066 33157 33208 33240 33268 33622 33666 33812 33832 33872 34047 34056 34073 34077 34088 34099 34135 34151 34168 34180 34283 34286 34327 36946 37023 37032 37542 39080 39094 39464 39532 39610 39615 40977 41031 41044 41047 41072 41098 41140 41217 41234 41254 45072 45101 45145 45205 45208 45278 45329 45581 45598 45606-45607 45631 45634 45670 45678 45687 457448.650015785639275e-20 9.710690472292815e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/447/1267?format=asciidefaultJ/MNRAS/447/1267/table1Spectroscopy of Octans candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMore[*] indicates more data in tables 3, 4, and/or 5meta.ref.urlcharName[1/61] Candidate identifiermeta.id;meta.mainintprimarym_Name[AB] Multiplicity index on Namemeta.code.multipchar2MASS2MASS designation (HHMMSSss+DDMMSSs)meta.idcharVmag? Apparent V magnitude (1)magphot.mag;em.opt.VfloatnullableKmag? 2MASS Ks magnitudemagphot.mag;em.IR.KfloatnullablepmRA? Proper motion RA component (2)mas/yrpos.pm;pos.eq.rafloatnullablepmDE? Proper motion Dec component (2)mas/yrpos.pm;pos.eq.decfloatnullableSpTMK spectral typesrc.spTypecharHRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatEWLi[10/365]? Equivalent width of LiI 6708{AA}0.1pmspect.line.eqWidthintnullablee_EWLi[10/20]? Error on Li equivalent width0.1pmstat.errorintnullableB_EWLi[30/50]? Upper limit on LiI detection0.1pminstr.saturation;stat.maxintnullableEWHa[-9/1.4] Equivalent width of Halpha emission0.1nmspect.line.eqWidth;em.line.HalphafloatRemarksNotes on binarity and CCFmeta.notechar_RAPositions from 2MASS name (right ascension part)degpos.eq.ra;meta.main_DEPositions from 2MASS name (declination part)degpos.eq.dec;meta.mainJ/MNRAS/447/1267/table2Previously proposed Octans membersSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of proposed membermeta.id;meta.maincharRefMembership reference, in refs.dat filemeta.bibcharVmagApparent V magnitude (1)magphot.mag;em.opt.VfloatKsmag2MASS Ks magnitudemagphot.mag;em.IR.KfloatpmRAProper motion RA component (2)mas/yrpos.pm;pos.eq.rafloatpmDEProper motion Dec component (2)mas/yrpos.pm;pos.eq.decfloatSpTMK spectral typesrc.spTypecharHRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV? Error on radial velocitykm/sstat.errorfloatnullabler_HRVRadial velocity reference, in refs.dat filemeta.ref;pos.framecharEWLi? Equivalent width of Li 6708{AA} line (3)0.1pmspect.line.eqWidthintnullableRemarksNotes on binarity and rotationmeta.notechar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/MNRAS/447/1267/table3New kinematic members of OctansrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName or ID of membermeta.id;meta.mainchardkinBest kinematic distancepcpos.distance;pos.heliocentricintVMAGAbsolute V at kinematic distancemagphys.magAbs;em.opt.BfloatDmuObserved total proper motion residual {Delta}{mu}mas/yrstat.fit.residualfloatDHRVObserved radial velocity residualkm/sstat.fit.residualfloatDvObserved total space motion residualkm/sstat.fit.residualfloatUHeliocentric U velocity componentkm/sphys.veloc;pos.cartesian.xfloatVHeliocentric V velocity componentkm/sphys.veloc;pos.cartesian.yfloatWHeliocentric W velocity componentkm/sphys.veloc;pos.cartesian.zfloatXHeliocentric X coordinatepcpos.cartesian.x;pos.galacticfloatYHeliocentric Y coordinatepcpos.cartesian.y;pos.galacticfloatZHeliocentric Z coordinatepcpos.cartesian.z;pos.galacticfloatJ/MNRAS/447/1267/table4Provisional Octans membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameID of provisional membermeta.id;meta.mainintm_Name[AB] Multiplicity index on Namemeta.code.multipchardkinBest kinematic distancepcpos.distance;pos.heliocentricintVMAGAbsolute V at kinematic distance (1)magphys.magAbs;em.opt.BfloatDmuObserved total proper motion residual {Delta}{mu}mas/yrstat.fit.residualfloatDHRVObserved radial velocity residual {Delta}HRVkm/sstat.fit.residualfloatDvObserved total space motion residual {Delta}vkm/sstat.fit.residualfloatUHeliocentric U velocity componentkm/sphys.veloc;pos.cartesian.xfloatVHeliocentric V velocity componentkm/sphys.veloc;pos.cartesian.yfloatWHeliocentric W velocity componentkm/sphys.veloc;pos.cartesian.zfloatXHeliocentric X coordinatepcpos.cartesian.x;pos.galacticfloatYHeliocentric Y coordinatepcpos.cartesian.y;pos.galacticfloatZHeliocentric Z coordinatepcpos.cartesian.z;pos.galacticfloatRemarksReason for provisional membership (2)meta.notecharJ/MNRAS/447/1267/table5Candidates observed by ROSATrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameID of candidatemeta.id;meta.mainintSurveyROSAT Bright or Faint Source Catalogmeta.idchar1RXSROSAT identifiermeta.idcharoffsetOffset from optical positionarcsecpos;arith.diffintPosErrROSAT positional uncertaintyarcsecstat.error;posintCR0.1-2.4keV count ratect/sphot.count;em.X-rayfloate_CRError on count ratect/sstat.errorfloatHR1[-1/1] ROSAT HR1 hardness ratiophot.flux;arith.ratiofloate_HR1[0.1/0.5] Error on hardness ratiostat.errorfloatlogLxlog X-ray luminosity (1)log(1e-07W)phys.luminosity;em.X-rayfloatlog(Lx/bol)log X-ray to bolometric luminosity ratio (2)phys.luminosity;em.X-rayfloatMember[Y] Octans kinematic member?meta.code.membercharJ/MNRAS/447/1267/refsMembership and RV referencesBibCodeBibcodemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharComCommentsmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference code from Table 2meta.notecharprimary