J/A+A/485/155ivo://CDS.VizieR/J/A+A/485/155doi:10.26093/cds/vizier.34850155CDSAlves de Oliveira C.Casali M.2008-07-19T22:13:28Z2008-07-19T22:09:43ZCDS support team

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

cds-question@unistra.frmolecular-cloudspre-main-sequence-starsinfrared-photometryVariability is a common characteristic of pre-main-sequence stars (PMS). Near-IR variability surveys of young stellar objects (YSOs) can probe stellar and circumstellar environments and provide information about the dynamics of the ongoing magnetic and accretion processes. Furthermore, variability can be used as a tool to uncover new cluster members in star formation regions. We hope to achieve the deepest near-IR variability study of YSOs targeting the rho Ophiuchi cluster. Fourteen epochs of observations were obtained with the Wide Field Camera (WFCAM) at the UKIRT telescope scheduled in a manner that allowed the study of variability on timescales of days, months, and years. Statistical tools, such as the multi-band cross correlation index and the reduced chi-square, were used to disentangle signals of variability from noise. Variability characteristics are compared to existing models of YSOs in order to relate them to physical processes, and then used to select new candidate members of this star-forming region. Variability in the near-IR is found to be present in 41% of the known population of rho Ophiuchi recovered in our sample. The behaviours shown are several and can be associated with the existence of spots on the stellar surface, variations in circumstellar extinction, or changes in the geometry of an accretion disc. Using variability, a new population of objects has been uncovered, that is believed to be part of the rho Ophiuchi cluster.2008A&A...485..155Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/485/155CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/438/813 : Stellar population in {rho} Oph cloud core (Strom+, 1995)J/ApJS/112/109 : Rho Oph Near-IR Positions and Photometry (Barsony+, 1997)J/A+A/359/113 : X-ray and IR study of Rho Oph dark cloud (Grosso+, 2000)J/ApJ/613/393 : X-ray and radio sources in {rho} Oph Core A (Gagne+, 2004)J/A+A/429/963 : XMM-Newton observation of the rho Oph cloud (Ozawa+, 2005)J/AJ/130/1733 : Optical spectroscopy of {rho} Oph stars (Wilking+, 2005)J/ApJ/630/381 : Mid-IR imaging in {rho} Oph (Barsony+, 2005)J/A+A/447/609 : 1.2mm continuum observations in rho Oph cloud (Stanke+, 2006)J/A+A/452/245 : Accretion in rho Oph pre-main sequence stars (Natta+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/485/155https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/485/155http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/485/155https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/485/155https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/485/155http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/485/155GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/485/155/table4 (List of variable objects (members and candidate members of rho Ophiuchi))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/485/155/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/485/155/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/485/155/table4?GETtext/xml+votable180.050000true246.4819583-24.09711110.005555555555555556Cone search capability for table J/A+A/485/155/tablea1 (Appendix list of variable objects with variability consistent with M dwarfs (could contain possible members of rho Ophiuchi))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/485/155/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/485/155/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/485/155/tablea1?GETtext/xml+votable180.050000true246.4776667-24.68688890.0055555555555555566/42981 42983 42992https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/485/155?format=asciiInfrareddefaultJ/A+A/485/155/table4List of variable objects (members and candidate members of rho Ophiuchi)SEDSED class (1)meta.code.classcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAOCJ2000.0 IAU designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharHmagAverage H magnitude over all available epochsmagphot.mag;em.IR.HfloatKmagAverage K magnitude over all available epochsmagphot.mag;em.IR.KfloatHampPeak-to-peak H magnitude amplitude variationmagsrc.var.amplitudefloatKampPeak-to-peak K magnitude amplitude variationmagsrc.var.amplitudefloat(H-K)ampPeak-to-peak H-K magnitude amplitude variationmagsrc.var.amplitudefloatSlope? Slope in the K vs. (H-K) diagramdegstat.fit.paramintnullableVFlag[Y0 ] Variability flags (2)meta.code;src.varcharVCausesVariability causes (3)meta.code;src.varcharRefReferences (4)meta.refchar_RARight ascension (derived from AOC) for Eq=J2000degpos.eq.ra;meta.main_DEDeclination (derived from AOC) for Eq=J2000degpos.eq.dec;meta.mainJ/A+A/485/155/tablea1Appendix list of variable objects with variability consistent with M dwarfs (could contain possible members of rho Ophiuchi)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAOCJ2000.0 IAU designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharHmagAverage H magnitude over all available epochsmagphot.mag;em.IR.HfloatKmagAverage K magnitude over all available epochsmagphot.mag;em.IR.KfloatHampPeak-to-peak H magnitude amplitude variationmagsrc.var.amplitudefloatKampPeak-to-peak K magnitude amplitude variationmagsrc.var.amplitudefloat(H-K)ampPeak-to-peak H-K magnitude amplitude variationmagsrc.var.amplitudefloat_RARight ascension (derived from AOC) for Eq=J2000degpos.eq.ra;meta.main_DEDeclination (derived from AOC) for Eq=J2000degpos.eq.dec;meta.main