J/MNRAS/491/215ivo://CDS.VizieR/J/MNRAS/491/215doi:10.26093/cds/vizier.74910215CDSBinks A.S.Chalifour M.Kastner J.H.Rodriguez D.Murphy S.J.,Principe D.A.Punzi K.Sacco G.G.Hernandez J.2024-08-20T20:14:32Z2020-04-01T14:17:41ZCDS support team

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

cds-question@unistra.frspectroscopic-binary-starslate-type-starsx-ray-sourcesstellar-agesline-intensitiesradial-velocityThe past two decades have seen dramatic progress in our knowledge of the population of young stars of age <200Myr that lie within 150pc of the Sun. These nearby, young stars, most of which are found in loose, comoving groups, provide the opportunity to explore (among many other things) the dissolution of stellar clusters and their diffusion into the field star population. Here, we exploit the combination of astrometric and photometric data from Gaia and photometric data from GALEX (UV) and 2MASS (near-IR) in an attempt to identify additional nearby, young, late-type stars. Specifically, we present a sample of 146 GALEX UV-selected late-type (predominantly K-type) field stars with Gaia-based distances <125pc (based on Gaia Data Release 1) that have isochronal ages <80Myr even if equal-components binaries. We investigate the spectroscopic and kinematic properties of this sample. Despite their young isochronal ages, only ~10 per cent of stars among this sample can be confidently associated with established nearby, young moving groups (MGs). These candidate MG members include five stars newly identified in this study. The vast majority of our sample of 146 nearby young star candidates have anomalous kinematics relative to the known MGs. These stars may hence represent a previously unrecognized population of young stars that has recently mixed into the older field star population. We discuss the implications and caveats of such a hypothesis - including the intriguing fact that, in addition to their non-young-star-like kinematics, the majority of the UV-selected, isochronally young field stars within 50pc appear surprisingly X-ray faint.2020MNRAS.491..215Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/491/215CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/491/215https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/491/215http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/491/215https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/491/215https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/491/215http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/491/215GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/491/215/table1 (Spectral-types, photometry and X-ray data for CYS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/491/215/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/491/215/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/491/215/table1?GETtext/xml+votable180.050000true1.2007094-49.99731330.005555555555555556Cone search capability for table J/MNRAS/491/215/table2 (Sub observed spectroscopically)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/491/215/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/491/215/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/491/215/table2?GETtext/xml+votable180.050000true4.048283330.53257860.0055555555555555566/151 321 576 1058 1156 1165 1172 1232 1775 3493 4669 4734 4863 4915 5022 5054 5081 5104 5234 5399 5447 5591 5706 6448 6487 6788 6868 6885 7060 7179 7466 7583 7767 7950 7954 8169 8265 8434 8607 8857 9320 9496 9621 9724 10109 10359 10678 10697 10911 11062 11302 11913 11926 12752 12844 13373 13482 13512 13614 13687 13857 13897 15181 15302 15926 16155 16345 16913 16930 17018 17080 17288 17517 17893 18092 18254 18345 18497 20327 21135 21851 22460 23113 23158 23173 23246 24249 24280 26050 26250 26572 26834 28080 28272 28386 28432 28499 28620 28643 29720 30766 31012 31196 32237 32956 32992 33022 33153 33160 33631 33636 33850 33988 34220 34360 34676 34762 35197 35291 35360 35398 35574 36139 36883 37125 38188 38359 38382 38738 38800 38827 39091 40204 41481 43246 43547 43756 44144 44272 44882 45367 45678 45684 46053 46207 46238 46291 46300 46546 47212 47285 47381 47555 48213 482628.650015785639275e-20 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/491/215?format=asciiX-raydefaultJ/MNRAS/491/215/table1Spectral-types, photometry and X-ray data for CYSSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS source identifier (HHMMSSss-DDMMSSs)meta.id;meta.maincharSpTypecSpectral-type interpolated from G-Ks coloursrc.spTypecharSpTyperSpectral-type quoted in SIMBADsrc.spTypecharNUVGalex NUV magnitudemagphot.mag;em.UVfloate_NUVUncertainty in Galex NUV magnitudemagstat.errorfloatGmagGaia DR2 G-band magnitudemagphot.mag;em.optfloatBPmagGaia DR2 RP-band magnitudemagphot.mag;em.opt.BfloatRPmagGaia DR2 BP-band magnitudemagphot.mag;em.opt.RfloatKsmag2MASS Ks-band magnitudemagphot.mag;em.IR.Kfloate_KsmagUncertainty in 2MASS Ks-band magnitudemagstat.error;phot.magfloatFX/FBol? X-ray to bolometric flux ratiophot.flux;arith.ratiofloatnullableNUVdiffExcess NUV magnitude compared to main-sequencemagphot.color.excessfloatSNameShort name, 2MASS JHHMM+DDMM (added by CDS)meta.idchar_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/491/215/table2Sub observed spectroscopicallySimbadSimbad column added by the CDSmeta.ref.urlcharSpTypeSpectral type (3)src.spTypecharEWHa? H{alpha} equivalent width0.1pmspect.line.eqWidthfloatnullable_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.mainSNRSignal-to-noise ratio (4)stat.snrcharl_EWLi2{sigma} upper limit flag on EWLimeta.code.errorcharInstInstrument (1)meta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS name (HHMMSSss+HHMMSSs), added by CDSmeta.id;meta.maincharSNameShort name (2MASS JHHMM+DDMM)meta.idcharn_SNameNotes on SName (2)meta.notecharGmagGaia DR2 G magnitudemagphot.mag;em.optfloatdDistancepcpos.distancefloatHJDHeliocentric Julain date (HJD-2450000)dtime.epochdoubleRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV? rms uncertainty on RVkm/sstat.errorfloatnullableEWLi? Lithium equivalent width0.1pmspect.line.eqWidthintnullablee_EWLi? rms uncertainty on EWLi0.1pmstat.errorintnullableJ/MNRAS/491/215/table3H{alpha} and Li EW datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS name (HHMMSSss+HHMMSSs), added by CDSmeta.id;meta.maincharSNameShor name (2MASS JHHM+DDMM)meta.idcharBP-RPGaia DR2 BP-RP colour indexmagphot.color;em.opt.B;em.opt.RfloatEWHa? H{alpha} equivalent width0.1nmspect.line.eqWidthdoublenullabler_EWHaReferences for EWHa (1)meta.ref;pos.framecharl_EWLiLimit flag on EWLimeta.code.errorcharEWLi? Lithium equivalent width0.1pmspect.line.eqWidthintnullabler_EWLiReferences for EwLi (1)meta.ref;pos.framecharl_Age[~<] Limit flag on Agemeta.code.error;time.agecharAge? Age or lower value of age intervalMyrtime.ageintnullableAgeu? Upper value of age intervalMyrtime.age;stat.maxintnullableJ/MNRAS/491/215/table4Gaia DR2 data for CPMCsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS source identifier (HHMMSSss+DDMMSSs)meta.id;meta.mainchardasAngular distance between source and CPMCpos.angDistancefloatplxsGaia DR2 parallax of sourcemaspos.parallax.trigfloate_plxsUncertainty in plxmasstat.errorfloatplxcParallax of CPMCmaspos.parallax.trigfloate_plxcUncertainty in plxmasstat.errorfloatpmRAsProper motion in right ascension of sourcemas/yrpos.pm;pos.eq.radoublee_pmRAsUncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmRAcProper motion in right ascension of CPMCmas/yrpos.pm;pos.eq.radoublee_pmRAcUncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEsProper motion in declination of sourcemas/yrpos.pm;pos.eq.decdoublee_pmDEsUncertainty in pmDEsmas/yrstat.error;pos.pm;pos.eq.decfloatpmDEcProper motion in declination of CPMCmas/yrpos.pm;pos.eq.decdoublee_pmDEcUncertainty in pmDEcmas/yrstat.error;pos.pm;pos.eq.decfloatGmagsG magnitude of sourcemagphot.mag;em.opt.Rfloate_GmagsUncertainty in Gmagmagstat.error;phot.magfloatGmagcG magnitude of CPMCmagphot.mag;em.opt.Rfloate_GmagcUncertainty in Gmagmagstat.error;phot.magfloatJ/MNRAS/491/215/table5Astrometry and kinematics for CYSe_U? Uncertainty in Ukm/sstat.error;pos.cartesian.xfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGDR2NameGaia DR2 source identifiermeta.idplxParallaxmaspos.parallax.trigfloate_plxUncertainty in plxmasstat.error;pos.parallaxfloatpmRAProper motion in right ascensionmas/yrpos.pm;pos.eq.radoublee_pmRAUncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declinationmas/yrpos.pm;pos.eq.decdoublee_pmDEUncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatRV1? Radial velocity measurement 1km/sspect.dopplerVelocfloatnullablee_RV1? Uncertainty in RV1km/sstat.errorfloatnullableRV2? Radial velocity measurement 1km/sspect.dopplerVelocfloatnullablee_RV2? Uncertainty in RV1km/sstat.errorfloatnullableRV3? Radial velocity measurement 1km/sspect.dopplerVelocfloatnullablee_RV3? Uncertainty in RV1km/sstat.errorfloatnullableRV4? Radial velocity measurement 1km/sspect.dopplerVelocfloatnullablee_RV4? Uncertainty in RV1km/sstat.errorfloatnullableRV5? Radial velocity measurement 1km/sspect.dopplerVelocfloatnullablee_RV5? Uncertainty in RV1km/sstat.errorfloatnullableRVfin? Final designated radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RVfin? Uncertainty in RVfinkm/sstat.errorfloatnullabler_RVReferences for RV measurements (1)meta.ref;pos.framecharbflagsMultiplicity flags (2)meta.code.errorcharUVelocity or lower value of velocity in direction of Galactic centre (3)km/sphys.velocfloatUu? Upper value of velocity in direction of Galactic centrekm/sphys.veloc;pos.dirCos;stat.maxfloatnullableVVelocity or lower value of velocity in direction of Galactic rotation (3)km/sphys.velocfloate_V? Uncertainty in Vkm/sstat.error;pos.cartesian.yfloatnullableVu? Upper value of velocity in direction of Galactic rotationkm/sphys.veloc;pos.dirCos;stat.maxfloatnullableWVelocity or lower value of velocity in direction of Galactic north pole (3)km/sphys.velocfloate_W? Uncertainty in Wkm/sstat.error;pos.cartesian.zfloatnullableWu? Upper value of Velocity in direction of Galactic north polekm/sphys.veloc;pos.dirCos;stat.maxfloatnullable2MASS2MASS source identifier (HHMMSSss+DDMMSSs)meta.id;meta.mainchar