J/ApJS/211/3ivo://CDS.VizieR/J/ApJS/211/3doi:10.26093/cds/vizier.22110003CDSParks J.R.Plavchan P.White R.J.Gee A.H.2018-01-30T07:17:50Z2014-05-12T15:32:38ZCDS support team

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

cds-question@unistra.frinfrared-photometrymolecular-cloudsvariable-starsyoung-stellar-objectsPresented are the results of a near-IR photometric survey of 1678 stars in the direction of the {rho} Ophiuchus ({rho} Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584 individual J-, H-, and Ks-band photometric measurements with a cadence of ~1 day are obtained over three observing seasons spanning ~2.5 yr; it is the most intensive survey of stars in this region to date. This survey identifies 101 variable stars with {Delta}Ks-band amplitudes from 0.044 to 2.31 mag and {Delta}(J-Ks) color amplitudes ranging from 0.053 to 1.47 mag. Of the 72 young {rho} Oph star cluster members included in this survey, 79% are variable; in addition, 22 variable stars are identified as candidate members. Based on the temporal behavior of the Ks time-series, the variability is distinguished as either periodic, long time-scale or irregular. This temporal behavior coupled with the behavior of stellar colors is used to assign a dominant variability mechanism. A new period-searching algorithm finds periodic signals in 32 variable stars with periods between 0.49 to 92 days. The chief mechanism driving the periodic variability for 18 stars is rotational modulation of cool starspots while 3 periodically vary due to accretion-induced hot spots. The time-series for six variable stars contains discrete periodic "eclipse-like" features with periods ranging from 3 to 8 days. These features may be asymmetries in the circumstellar disk, potentially sustained or driven by a proto-planet at or near the co-rotation radius. Aperiodic, long time-scale variations in stellar flux are identified in the time-series for 31 variable stars with time-scales ranging from 64 to 790 days. The chief mechanism driving long time-scale variability is variable extinction or mass accretion rates. The majority of the variable stars (40) exhibit sporadic, aperiodic variability over no discernable time-scale. No chief variability mechanism could be identified for these variable stars.2014ApJS..211....3Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/211/3CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/289 : JKH photometry in LDN 1688 (Wilking+, 2008)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/ApJ/751/22 : Candidates of the {rho} Oph cluster (Barsony+, 2012)J/A+A/519/A34 : YSOs in DROXO (Deep rho Oph XMM obs.) (Pillitteri+, 2010)J/A+A/515/A75 : Low-mass pop. in {rho} Oph cloud (Alves de Oliveira+, 2010)J/ApJ/719/550 : Deep NIR imaging of {rho} Oph cloud core (Marsh+, 2010)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/ApJS/175/191 : Variables from 2MASS calibration fields (Plavchan+, 2008)J/A+A/485/155 : HK photometry of rho Oph PMS stars (Alves de Oliveira+, 2008)J/A+A/461/183 : Variability of classical T Tauri (Grankin+, 2007)J/A+A/452/245 : Near-IR photometry of PMS stars in rho Oph (Natta+, 2006)J/ApJ/630/381 : Mid-IR imaging in {rho} Oph (Barsony+, 2005)J/A+A/372/173 : ISOCAM obs. of the rho Ophiuchi cloud (Bontemps+, 2001)J/A+A/359/113 : X-ray and IR study of Rho Oph dark cloud (Grosso+, 2000)J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)J/ApJS/112/109 : Rho Oph Near-IR Positions and Photometry (Barsony+, 1997)J/ApJ/438/813 : Stellar population in {rho} Oph cloud core (Strom+, 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/211/3https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/211/3http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/211/3https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/211/3https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/211/3http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/211/3GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/211/3/table1 (Catalog of 2MASS Stars in {rho} Oph)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/211/3/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/211/3/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/211/3/table1?GETtext/xml+votable180.050000true246.73075889-25.067986940.005555555555555556Cone search capability for table J/ApJS/211/3/table3 (Catalog of Variable Stars in {rho} Oph)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/211/3/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/211/3/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/211/3/table3?GETtext/xml+votable180.050000true246.73226889-25.137508060.0055555555555555566/429818.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/211/3?format=asciiInfrareddefaultJ/ApJS/211/3/table1Catalog of 2MASS Stars in {rho} OphrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[246.73/246.89] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-25.19/-24.19] Declination (J2000)degpos.eq.dec;meta.mainJmag[8/17.9] 2MASS J band magnitude (1)magphot.mag;em.IR.Jfloate_Jmag[0/0.3]? Uncertainty in Jmagmagstat.error;phot.mag;em.IR.Jfloatnullableo_Jmag[0/263] Number of J band observationsmeta.numberintHmag[7.4/16.9] 2MASS H band magnitude (1)magphot.mag;em.IR.Hfloate_Hmag[0/0.3]? Uncertainty in Hmagmagstat.error;phot.mag;em.IR.Hfloatnullableo_HmagNumber of H band observationsmeta.numberintKsmag[6.7/16.1] 2MASS Ks band magnitude (1)magphot.mag;em.IR.Kfloate_Ksmag[0/0.2]? Uncertainty in Ksmagmagstat.error;phot.mag;em.IR.Kfloatnullableo_KsmagNumber of Ks band observationsmeta.numberint2MASS2MASS identification (HHMMSSss+DDMMSSs; J2000) for the new candidate members (2)meta.id;meta.maincharVVariable star (link to properties in table 3)meta.ref.urlintnullable2MCross-match with the 2MASS data within 2"meta.ref.urlintnullableJ/ApJS/211/3/table3Catalog of Variable Stars in {rho} OphrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[246.73/246.89] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-25.15/-24.20] Declination (J2000)degpos.eq.dec;meta.mainVarVariability flags (1)meta.code;src.varintDKsmag[0.04/2.4] Ks-band amplitude of variabilitymagphot.mag;em.IR.KfloatD(J-H)[0.04/1.3]? J-H amplitude of variabilitymagsrc.var.amplitudefloatnullableD(H-Ks)[0.009/1.4]? H-Ks amplitude of variabilitymagsrc.var.amplitude;em.IR.HfloatnullableTypeVariability type: "LTV" (long time-scale variables), "irregular", "periodic", or "periodic/LTV")meta.notecharClassYSO class (0, I, II or III) (2)src.classnullableonCloud?[yes/no ] "On Cloud"? (otherwise within the "field")meta.code.membercharT1Details from Table 1meta.ref.urlchar