J/ApJ/664/481ivo://CDS.VizieR/J/ApJ/664/481doi:10.26093/cds/vizier.16640481CDSBarrado y Navascues DStauffer J.R.Morales-Calderon M.Bayo A.,Fazzio G.Megeath T.Allen L.Hartmann L.W.Calvet N.2017-11-10T11:15:05Z2009-07-04T09:45:07ZCDS support team

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

cds-question@unistra.frphotometryapparent-magnitudepre-main-sequence-starsyoung-stellar-objectsopen-star-clustersWe present multiwavelength optical and IR photometry of 170 previously known low-mass stars and brown dwarfs of the 5Myr Collinder 69 cluster ({lambda} Orionis). The new photometry supports cluster membership for most of them, with less than 15% of the previous candidates identified as probable nonmembers. The near-IR photometry allows us to identify stars with IR excesses, and we find that the Class II population is very large, around 25% for stars (in the spectral range M0-M6.5) and 40% for brown dwarfs, down to 0.04M_{sun}_, despite the fact that the H{alpha} equivalent width is low for a significant fraction of them. In addition, there are a number of substellar objects, classified as Class III, that have optically thin disks. The Class II members are distributed in an inhomogeneous way, lying preferentially in a filament running toward the southeast. The IR excesses for the Collinder 69 members range from pure Class II (flat or nearly flat spectra longward of 1um), to transition disks with no near-IR excess but excesses beginning within the IRAC wavelength range, to two stars with excess only detected at 24um. Collinder 69 thus appears to be at an age where it provides a natural laboratory for the study of primordial disks and their dissipation.2007ApJ...664..481Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/664/481CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/118/2409 : VRI photometry of {lambda} Ori PMS stars (Dolan+, 1999)J/AJ/121/2124 : {lambda} Ori pre-main-sequence stars photometry (Dolan+, 2001)J/AJ/123/387 : VRI phot. of {lambda} Ori star-forming region (Dolan+, 2002)J/ApJ/610/1064 : lambda Ori substellar population (Barrado y Navascues+, 2004)J/A+A/488/167 : Low-mass stars in {sigma} Ori and {lambda} Ori (Sacco+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/664/481https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/664/481http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/664/481https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/664/481https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/664/481http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/664/481GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/664/481/table3 (*Photometry for Candidate Members of the {lambda} Orionis Cluster (CAHA/Omega2000))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/664/481/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/664/481/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/664/481/table3?GETtext/xml+votable180.050000true83.44670839.92736110.0055555555555555566/23717 23719 237288.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/664/481?format=asciiOpticaldefaultJ/ApJ/664/481/table3*Photometry for Candidate Members of the {lambda} Orionis Cluster (CAHA/Omega2000)e_Ksmag? Error on K_s_ band magnitudemagstat.error;phot.mag;em.IR.KfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_LOriSimbad column added by the CDSmeta.ref.urlcharLOriSequence number (lOri-CFHT NNN in Simbad)meta.id;meta.mainintprimaryRcmagCFHT Cousins R band magnitudemagphot.mag;em.opt.Rfloate_RcmagError in Rc band magnitudemagstat.error;phot.mag;em.opt.RfloatIcmagCFHT Cousins I band magnitudemagphot.mag;em.opt.Ifloate_IcmagError in Ic band magnitudemagstat.error;phot.mag;em.opt.IfloatJmag? 2MASS J band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? Error in J band magnitudemagstat.error;phot.mag;em.IR.JfloatnullableHmag? 2MASS H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Error on H band magnitudemagstat.error;phot.mag;em.IR.HfloatnullableKsmag? 2MASS K_s_ band magnitudemagphot.mag;em.IR.Kfloatnullable3.6mag? Spitzer/IRAC 3.6micron band magnitudemagphot.mag;em.IR.3-4umfloatnullablee_3.6mag? Error on 3.6micron band magnitudemagstat.errorfloatnullable4.5mag? Spitzer/IRAC 4.5micron band magnitudemagphot.mag;em.IR.4-8umfloatnullablee_4.5mag? Error on 4.5micron band magnitudemagstat.errorfloatnullable5.8mag? Spitzer/IRAC 5.8micron band magnitudemagphot.flux.density;em.IR.4-8umfloatnullablee_5.8mag? Error on 5.8micron band magnitudemagstat.errorfloatnullable8.0mag? Spitzer/IRAC 8.0micron band magnitudemagphot.mag;em.IR.8-15umfloatnullablee_8.0mag? Error on 8.0micron band magnitudemagstat.errorfloatnullable24mag? Spitzer/IRAC 24micron band magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_24mag? Error on 24micron band magnitudemagstat.errorfloatnullableMm[YN?] Final membershipmeta.code.member;phys.atmol.finalcharSimbadSimbad column added by the CDSchar_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/ApJ/664/481/table1*Additional Near-IR Photometry for the Candidate Members of the {lambda} Orionis Cluster (WHT/INGRID, La Palma, 2002Nov and 2003Feb)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLOriSequence number (lOri-CFHT NNN in Simbad)meta.id;meta.mainintImagI band magnitudemagphot.mag;em.opt.IfloatJmagWHT/INGRID J band magnitudemagphot.mag;em.IR.Jfloate_JmagError in J band magnitudemagstat.error;phot.mag;em.IR.JfloatHmag? WHT/INGRID H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Error in H band magnitudemagstat.error;phot.mag;em.IR.HfloatnullableKsmag? WHT/INGRID K_s_ band magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag? Error in Ks band magnitudemagstat.error;phot.mag;em.IR.Kfloatnullable