J/AJ/156/71ivo://CDS.VizieR/J/AJ/156/71doi:10.26093/cds/vizier.51560071CDSCody A.M.Hillenbrand L.A.2020-01-07T10:50:30Z2019-02-12T07:07:55ZCDS support team

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

cds-question@unistra.frstellar-associationsmolecular-cloudsyoung-stellar-objectsaccretionstellar-spectral-typesvariable-starsThe K2 Mission has photometrically monitored thousands of stars at high precision and cadence in a series of ~80-day campaigns focused on sections of the ecliptic plane. During its second campaign, K2 targeted over 1000 young stellar objects (YSOs) in the ~1-3 Myr {rho} Ophiuchus and 5-10 Myr Upper Scorpius regions. From this set, we have carefully vetted photometry from WISE and Spitzer to identify those YSOs with infrared excess indicative of primordial circumstellar disks. We present here the resulting comprehensive sample of 288 young disk-bearing stars from B through M spectral types and analysis of their associated K2 light curves. Using statistics of periodicity and symmetry, we categorize each light curve into eight different variability classes, notably including "dippers" (fading events), "bursters" (brightening events), stochastic, and quasi-periodic types. Nearly all (96%) of disk-bearing YSOs are identified as variable at 30-minute cadence with the sub-1% precision of K2. Combining our variability classifications with (circum)stellar properties, we find that the bursters, stochastic sources, and the largest amplitude quasi-periodic stars have larger infrared colors, and hence stronger circumstellar disks. They also tend to have larger H{alpha} equivalent widths, indicative of higher accretion rates. The dippers, on the other hand, cluster toward moderate infrared colors and low H{alpha}. Using resolved disk observations, we further find that the latter favor high inclinations, except for a few notable exceptions with close to face-on disks. These observations support the idea that YSO time-domain properties are dependent on several factors, including accretion rate and view angle.2018AJ....156...71Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/156/71CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/688/377 : Low-mass objects in Upper Scorpius. II. (Slesnick+, 2008)J/ApJ/705/1226 : Planet-bearing stars in Spitzer (Bryden+, 2009)J/ApJ/724/835 : The Spitzer c2d survey of WTTSs. III. (Wahhaj+, 2010)J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)J/ApJS/211/3 : NIR photometry variability in {rho} Oph (Parks+, 2014)J/A+A/579/A66 : Accretion in {rho}-Ophiucus (Manara+, 2015)J/AJ/155/196 : Analysis of K2 LCs for members of USco & {rho} OphJ/AJ/156/75 : Circumstellar disks in the Upper Sco associationJ/AJ/156/76 : New young stars and brown dwarfs in Upper Sco (Luhman+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/156/71https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/156/71http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/156/71https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/156/71https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/156/71http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/156/71GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/156/71/table1 (Young inner disk-bearing stars in K2 Campaign 2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/71/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/71/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/71/table1?GETtext/xml+votable180.050000true245.8461169-29.02587810.0055555555555555564/2772 5/10744 10745 10746 11077 11092 11094 11100 6/29348 29352 29358 30721 30733 42903 42911 42933 42935 42953 42955 42958 42959 42989 42990 42991 42992 42994 42995 43000 43001 43002 44304 44307 44316 44317 44319 44374 44385 44386 44388 44389 44390 44404https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/156/71?format=asciidefaultJ/AJ/156/71/table1Young inner disk-bearing stars in K2 Campaign 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEPIC[202610930/210282534] EPIC catalog identifiermeta.id;meta.mainlongprimary2MASS2MASS catalog identifier (JHHMMSSss+DDMMSSs)meta.idcharmoreindicates variability properties in Table 2 for this objectmeta.ref.urlcharSpTypeSpectral typesrc.spTypecharn_SpType[a] Note on SpType (1)meta.notecharRefReferencemeta.ref;pos.framecharBibcodeBibcode of the referencemeta.bib.bibcodecharBlend[Y] Blend flag (2)meta.code.errorcharRegionRegion (Oph or Sco)meta.notecharFlag[BFY] Sample flag (3)meta.code.errorcharSimbadSimbad column added by the CDSmeta.ref.urlchar_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/AJ/156/71/table2Variability properties of young disk-bearing stars in K2 Campaign 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEPIC[202610930/210282534] EPIC catalog identifiermeta.id;meta.mainlong2MASS2MASS catalog identifier (JHHMMSSss+DDMMSSs)meta.idcharVTypeVariability type (1)meta.notecharAmp[0.001/2.41] Amplitude, in normalized flux units (2)meta.unit;src.var.amplitude;arith.ratiofloatTime[0.28/95.25] Variability timescale (3)dtime.scalefloatQ[0.02/1.01] Quasi-periodicity (4)stat.fit.omcfloatM[-1.35/1.24] Flux asymmetry (5)src.morph.paramfloat