J/MNRAS/542/L126ivo://CDS.VizieR/J/MNRAS/542/L126doi:10.26093/cds/vizier.75429126CDSLuhman K.L.2025-08-27T20:14:52Z2025-08-06T12:43:07ZCDS support team

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

cds-question@unistra.frbrown-dwarfsinfrared-astronomyspectroscopystellar-spectral-typesI present an analysis of archival spectra of 200 sources toward the Orion Nebula Cluster (ONC) that were obtained with the Near-Infrared Spectrograph (NIRSpec) onboard the James Webb Space Telescope (JWST). I have used these data to assess cluster membership and measure spectral types for the targets. Fifty-three sources are classified as likely cluster members, 24 of which have spectral types that are suggestive of brown dwarfs (>M6). Seven of the NIRSpec targets were previously identified as "Jupiter-mass binary objects" (JuMBOs), all of which are background sources rather than brown dwarfs based on the NIRSpec data. The spectral classifications of those objects are consistent with the results of my recent study of the JWST photometry in the ONC, which found that only a few JuMBO components have the colours expected for brown dwarfs, none of which form pairs that have uniquely wide separations or low masses relative to known binary brown dwarfs.2025MNRAS.542L.126Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/542/L126CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)J/AJ/146/85 : Spectral types of 1576 optical stars in ONCJ/ApJ/975/162 : Spectra of brown dwarf candidates in ONC from JWSThttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/542/L126https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/542/L126http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/542/L126https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/542/L126https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/542/L126http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/542/L126GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/542/L126/table1 (Spectral and membership classifications)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/542/L126/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/542/L126/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/542/L126/table1?GETtext/xml+votable180.050000true83.71658889-5.388880.0055555555555555566/21438-21439https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/542/L126?format=asciiInfrareddefaultJ/MNRAS/542/L126/table1Spectral and membership classificationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintspShow the spectrummeta.ref.urlcharID[3/3249] Source number in MPT/APT catalogmeta.id;meta.mainintNameOther source namemeta.idcharRA_ICRSRight ascension (ICRS) (1)degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) (1)degpos.eq.dec;meta.mainSpTypeSpectral typesrc.spTypecharr_SpTypeSpectral type reference (2)meta.ref;pos.framecharAK? K band extinction from NIRSpecmagphys.absorptionfloatnullableMember[yes no?] ONC member?meta.code.membercharEvidenceEvidence of membership (3)meta.notechar