J/ApJS/191/389ivo://CDS.VizieR/J/ApJS/191/389doi:10.26093/cds/vizier.21910389CDSCody A.M.Hillenbrand L.A.2017-11-29T11:48:39Z2011-02-02T12:40:31ZCDS support team

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

cds-question@unistra.frastronomical-object-identificationinfrared-photometryglobular-star-clustersvariable-starsWe present high-precision photometry on 107 variable low-mass stars and brown dwarfs in the ~3Myr {sigma} Orionis open cluster. We have carried out I-band photometric monitoring within two fields, encompassing 153 confirmed or candidate members of the low-mass cluster population, from 0.02 to 0.5M_{sun}_. We are sensitive to brightness changes on timescales from 10 minutes to two weeks with amplitudes as low as 0.004mag, and find variability on these timescales in nearly 70% of cluster members. We identify both periodic and aperiodic modes of variability, as well as semi-periodic rapid fading events that are not accounted for by the standard explanations of rotational modulation of surface features or accretion. We have incorporated both optical and infrared color data to uncover trends in variability with mass and circumstellar disks.2010ApJS..191..389Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/191/389CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/A+A/478/667 : The Mayrit catalogue (Caballero, 2008)J/MNRAS/385/2210 : Spectroscopy around lam Ori and sig Ori (Maxted+, 2008)J/A+A/488/167 : Low-mass stars in {sigma} Ori and {lambda} Ori (Sacco+,J/ApJ/662/1067 : Sptizer observations of sigma Orionis (Hernandez+, 2007)J/A+A/446/501 : XMM observations of sigma Ori cluster (Franciosini+, 2006)J/MNRAS/356/1583 : RV of Sigma Ori low-mass candidate members (Burningham+,J/MNRAS/356/89 : sigma Ori low-mass stars (Kenyon+, 2005)J/A+A/419/249 : RJHKs photometry of sigma Ori low-mass stars (Scholz+, 2004)J/AJ/128/2316 : BVRIJHKs photometry in sigma Ori cluster (Sherry+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/191/389https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/191/389http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/191/389https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/191/389https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/191/389http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/191/389GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/191/389/table3 (Objects with detected I-band periodic variability)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/191/389/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/191/389/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/191/389/table3?GETtext/xml+votable180.050000true84.3669167-2.60180560.005555555555555556Cone search capability for table J/ApJS/191/389/table4 (Objects with detected I-band aperiodic variability)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/191/389/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/191/389/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/191/389/table4?GETtext/xml+votable180.050000true84.4650417-2.59047220.005555555555555556Cone search capability for table J/ApJS/191/389/table1 (*{sigma} Orionis cluster : confirmed and candidate members in our photometric sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/191/389/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/191/389/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/191/389/table1?GETtext/xml+votable180.050000true84.3669167-2.60180560.005555555555555556Cone search capability for table J/ApJS/191/389/table2 (Photometry of confirmed and candidate cluster members in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/191/389/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/191/389/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/191/389/table2?GETtext/xml+votable180.050000true84.3669167-2.60180560.0055555555555555566/22851 228548.650015785639275e-20 3.3785437584409506e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/191/389?format=asciiInfrareddefaultJ/ApJS/191/389/table3Objects with detected I-band periodic variabilitySimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName2MASS or CTIO identification (JHHMMSSss+DDMMSSs)meta.idcharPerPerioddtime.periodfloate_Per3{sigma} period uncertaintydstat.errorfloatAmpAmplitudemagphot.magfloate_Amp3{sigma} amplitude uncertaintymagstat.errorfloatVtypeVariable type (1)meta.notecharMm[YMN] Membership (2)meta.code.membercharf_Mm[a-d] Flag on Mm (3)meta.codechar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar_RAPositions from object name (right ascension part)degpos.eq.ra;meta.main_DEPositions from object name (declination part)degpos.eq.dec;meta.mainJ/ApJS/191/389/table4Objects with detected I-band aperiodic variabilityrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName2MASS identification (JHHMMSSss+DDMMSSs)meta.id;meta.maincharAmpPeak-to-peak amplitudemagsrc.var.amplitudefloate_AmpAmplitude rmsmagstat.errorfloatMm[YM] Membership (1)meta.code.membercharf_Mm[ab] Flag on Mm (2)meta.codecharEW? H{alpha} equivalent width0.1nmspect.line.eqWidth;em.line.Halphafloatnullablee_EW? EW uncertainty0.1nmstat.error;spect.line.eqWidthfloatnullabler_EW[1-4] Reference for EW (3)meta.ref;spect.line.eqWidthchar_RAPositions from object name (right ascension part)degpos.eq.ra;meta.main_DEPositions from object name (declination part)degpos.eq.dec;meta.mainJ/ApJS/191/389/table1*{sigma} Orionis cluster : confirmed and candidate members in our photometric sampleSimbadNameSimbad column added by the CDSmeta.idcharSpTMK spectral typesrc.spTypecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName2MASS or CTIO name (JHHMMSSss+DDMMSSs) or S Ori JHHMMSS.s+DDMMSS namemeta.idcharprimaryVSimbad column added by the CDSmeta.ref.urlcharONameOther designations (1)meta.id;meta.maincharSpT2MK spectral type from litteraturesrc.spTypecharr_SpT2? Reference for SpType2 (4)meta.ref;pos.frameintnullableVar[Y] for variablemeta.code;src.varcharr_VarReference(s) for Var (4)meta.ref;pos.framecharMmEMembership explanation(s) (2)meta.code.membercharr_MmEReference(s) for membership (4)meta.ref;pos.framecharNMmEPossible non-member explanation (2)(3)meta.code.membercharr_NMmEReference(s) for possible non-membership (4)meta.ref;pos.framecharOCatDisplay the data of catalogs that are given in note (1)meta.ref.urlchar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar_RAPositions from object name (right ascension part)degpos.eq.ra;meta.main_DEPositions from object name (declination part)degpos.eq.dec;meta.mainJ/ApJS/191/389/table2Photometry of confirmed and candidate cluster members in the sampleIcmagCousins I-band magnitudemagphot.mag;em.opt.Ifloate_RcmagRcmag uncertaintymagstat.error;phot.mag;em.opt.RfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName2MASS JHHMMSSss+DDMMSSs or S Ori JHHMMSS.s+DDMMSS designationmeta.idcharRcmagCousins R-band magnitudemagphot.mag;em.opt.Rfloate_IcmagIcmag uncertaintymagstat.error;phot.mag;em.opt.IfloatJmag? 2MASS J-band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? Jmag uncertaintymagstat.error;phot.mag;em.IR.JfloatnullableHmag? 2MASS H-band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Hmag uncertaintymagstat.error;phot.mag;em.IR.HfloatnullableKsmag? 2MASS Ks-band magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag? Ksmag uncertaintymagstat.error;phot.mag;em.IR.Kfloatnullable_RAPositions from object name (right ascension part)degpos.eq.ra;meta.main_DEPositions from object name (declination part)degpos.eq.dec;meta.main