J/A+A/686/A161ivo://CDS.VizieR/J/A+A/686/A161doi:10.26093/cds/vizier.36860161CDSZerjal M.Martin E.L.Perez-Garrido A.2025-08-26T20:01:04Z2024-06-07T09:20:05ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyopen-star-clustersspectroscopySigma Orionis is an open cluster in the nearest giant star formation site -- Orion. Its youth (3-5Myr), low reddening, and relative vicinity make it an important benchmark cluster to study stellar and substellar formation and evolution. Young star-forming sites are complex and hierarchical. Precision astrometry from Gaia DR3 enables the exploration of their fine structure. We used the modified convergent point technique to kinematically re-evaluate the members in the Sigma Orionis cluster and its vicinity. We present clear evidence for three kinematically distinct groups in the Sigma Orionis region. The second group, the RV Orionis association, is adjacent to the Sigma Orionis cluster and is composed only of low-mass stars. The third group, the Flame association, whose age is comparable to that of Sigma Orionis, overlaps with the younger NGC 2024 in the Flame Nebula. In total, we have discovered 105 members of this complex not previously found in the literature (82 in Sigma Orionis, 19 in the Flame association, and 4 in the RV Orionis association).2024A&A...686A.161Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/686/A161CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/686/A161https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/686/A161http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/686/A161https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/686/A161https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/686/A161http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/686/A161GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/686/A161/tablea1 (Members of Sigma Orionis)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/686/A161/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/686/A161/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/686/A161/tablea1?GETtext/xml+votable180.050000true85.48569056-1.771411110.0055555555555555565/5712-5713 5715 6/21486 22807 22856-22857 22859 228721.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/686/A161?format=asciidefaultJ/A+A/686/A161/tablea1Members of Sigma OrionisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpEWindicates spectroscopic indicators and spectral types in table C1meta.ref.urlcharGaiaDR3Gaia DR3 source_id (source_id)meta.id;meta.mainprimaryRA_ICRSRight ascension (ICRS) at Ep=2016.0 (ra)degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0 (dec)degpos.eq.dec;meta.mainpmRAProper motion in RA (pmra)mas/yrpos.pm;pos.eq.radoublepmDEProper motion in Dec (pmdec)mas/yrpos.pm;pos.eq.decdoubleSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexedplxParallax (parallax)maspos.parallax.trigdoublee_plxParallax error (parallax_error)masstat.error;pos.parallaxdoubleRV? Radial velocity (radial_velocity)km/sphys.veloc;pos.heliocentricdoublenullablee_RV? Radial velocity error (radial_velocity_error)km/sstat.errordoublenullabler_RV[1/2]? Radial velocity reference (radial_velocity_reference2) (1)meta.ref;pos.frameintnullableRUWE? Ruwe from Gaia DR3 (ruwe)stat.errordoublenullableGmag? G magnitude from Gaia DR3 (phot_g_mean_mag)magphot.mag;em.optdoublenullableG-RP? G-RP color from Gaia DR3 (G-Rp)magphot.color;em.opt;em.optdoublenullableMembCluster membership (memb)meta.code.membercharcMembership parameter (c)meta.code.member;stat.paramdoubleoutlierOutlier type (outlier)src.classcharJ/A+A/686/A161/tablec1Spectroscopic indicators and spectral typesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 source_id (source_id)meta.id;meta.mainpEWLi? Pseudo equivalent width of lithium (pEWLi)0.1nmspect.line.eqWidthdoublenullablee_pEWLi? Pseudo equivalent width of lithium error (epEWLi)0.1nmstat.errordoublenullabler_pEWLiReference for pEWLi (refLi) (1)meta.ref;pos.framecharEWHa? Equivalent width of Halpha (EWHa)0.1nmspect.line.eqWidthdoublenullablee_EWHa? Equivalent width of Halpha error (eEWHa)0.1nmstat.errordoublenullabler_EWHaReference for EWHa (refHa) (1)meta.ref;pos.framecharveiled?[Y/N] Is a star veiled? [Y: yes, N: no] (veiledYN)meta.codecharpEWNa? Pseudo equivalent width of sodium (pEWNa)0.1nmspect.line.eqWidthdoublenullablee_pEWNa? Pseudo equivalent width of sodium error (epEWNa)0.1nmstat.errordoublenullabler_pEWNaReference for pEWNa (refNa) (1)meta.ref;pos.framecharSpTypeSpectral type (SpT)src.spTypecharr_SpType? Spectral type reference (refSpT) (1)meta.ref;pos.frameintnullable