J/MNRAS/428/2824ivo://CDS.VizieR/J/MNRAS/428/2824doi:10.26093/cds/vizier.74282824CDSKoen C.2024-07-20T20:13:26Z2014-03-21T14:18:15ZCDS support team

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

cds-question@unistra.frdwarf-starsphotometryIn this paper, a summary of optical time-series photometry of 125 ultracool dwarfs is given. The observing strategy was to monitor each object continuously for 2-3h in order to ascertain whether it was rapidly variable. Many of the targets were observed at multiple epochs, to follow up possible short time-scale variability, or to test for slow brightness changes on longer time-scales. The 353 data sets obtained contain nearly 22000 individual measurements. Optical (I_C_) magnitudes, accurate to roughly 0.1-0.2mag, were derived for 21 objects for which there is no optical photometry in the literature. It is shown that photometry is affected by variable seeing in a large percentage of the time-series observations. Since this could give the appearance of variability intrinsic to the objects, magnitudes are modelled as functions of both time and seeing. Several ultracool dwarfs which had not been monitored before are variable, according to certain model-fitting criteria. A number of objects with multi-epoch observations appear to be variable on longer time-scales. Since testing for variability is far from being straightforward, the time-series data are made available so that interested readers can perform their own analyses.2013MNRAS.428.2824Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/428/2824CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/126/1526 : IR photometry of ultracool dwarfs (Bouy+, 2003)J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)J/AJ/126/2449 : Nearby ultracool dwarfs in galactic plane (Reid+, 2003)J/A+A/446/515 : Distances of nearby ultracool dwarfs (Phan-Bao+, 2006)J/MNRAS/382/515 : SDSS ultracool and halo WD candidates (Vidrih+, 2007)J/AJ/133/439 : Luminosity function of M7-L8 ultracool dwarfs (Cruz+, 2007)J/AJ/133/2258 : Activity and kinematics of ultracool dwarfs (Schmidt+, 2007)J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)J/ApJ/723/684 : NIRSPEC ultracool dwarf RV survey (Blake+, 2010)J/MNRAS/404/1817 : 2MASS/SDSS data for 806 ultracool dwarfs (Zhang+, 2010)J/A+A/522/A112 : L5 and later dwarf candidates i'z' photometry (Reyle+, 2010)J/ApJ/746/23 : Radio observations of ultracool dwarf stars (McLean+, 2012)J/A+A/549/A131 : Radio survey of ultracool dwarfs (Antonova+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/428/2824https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/428/2824http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/428/2824https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/428/2824https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/428/2824http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/428/2824GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/428/2824/table1 (Observing log and details of the objects observed)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/428/2824/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/428/2824/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/428/2824/table1?GETtext/xml+votable180.050000true3.7323125-48.73809720.0055555555555555566/221 399 4226 4630 4775 8794 12430 12466 12582 16546 16609 17075 17096 17530 17594 18166 18683 19857 20754 21171 21209 21296 21728 21835 22759 22861 23010 23471 24581 24632 24716 25015 25266 25314 25433 27019 27058 27648 28006 29018 29301 30061 30749 30764 30883 31011 31062 31144 31268 31309 31324 31340 31534 31594 31601 31871 33398 33767 34102 34400 34626 34660 34780 34803 34893 35364 35412 35902 36223 36560 36602 36821 36845 36956 38039 38145 38164 38176 38239 38812 39109 39185 39482 39485 39807 40022 40332 40485 40669 40738 40882 40901 41159 41984 42090 42261 42309 42635 43062 43422 43480 43512 43875 43957 44118 44314 44416 44486 44807 44954 45178 45564 45566 45834 46208 47012 47192 47357 48171 48300 48593 48817 48957 48990 491391.5062136169708525e-19 3.3785437584409506e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/428/2824?format=asciidefaultJ/MNRAS/428/2824/table1Observing log and details of the objects observedRmag3? R(Cousins) magnitudemagphot.mag;em.opt.RfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSNameShort star name (HHMM+DDMM)meta.idcharprimaryNameStar namemeta.id;meta.maincharSpTMK spectral typesrc.spTypecharJmag2MASS J magnitudemagphot.mag;em.IR.JfloatImag? I(Cousins) magnitudemagphot.mag;em.opt.IfloatnullableRmag? R(Cousins) magnitudemagphot.mag;em.opt.Rfloatnullabler_Rmag? Reference for Icmag and Rmag (3)meta.ref;pos.frameintnullableImag2? I(Cousins) magnitudemagphot.mag;em.opt.IfloatnullableRmag2? R(Cousins) magnitudemagphot.mag;em.opt.Rfloatnullabler_Rmag2? Reference for Icmag2 and Rmag2 (3)meta.ref;pos.frameintnullableImag3? I(Cousins) magnitudemagphot.mag;em.opt.Ifloatnullabler_Rmag3? Reference for Icmag3 and Rmag3 (3)meta.ref;pos.frameintnullablel_SepLimit flag on Sepmeta.code.errorcharSep? Angular separation for binariesmaspos.angDistanceintnullableMult[XO?] Multiplicity code (1)meta.code.multipcharr_SepReference for Sep or Mult (4)meta.ref;pos.framecharNNumber of available observationsmeta.numberintnullableVarVariability code (2)meta.code;src.varcharSimbadNameSimbad column added by the CDSmeta.idcharSimbadSimbad 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/MNRAS/428/2824/table2The observing log, and some quantities derived from the photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSNameShort name (HHMM-DDMM)meta.idcharHJDStart HJD (HJD-2450000)dtime.startdoubleFilt[RIZW] Filter (1)meta.id;instr.filtercharTrunRun lengthhtime.intervalfloatTexpExposure timestime.duration;obs.exposureintTexp2? Upper value of exposure time intervalstime.expointnullableNNumber of useful exposures obtainedmeta.numberintsigmaStandard deviation of the measurementsmmagstat.stdevintbetas? Slope of the seeing regression (2)mmag/arcsecstat.fit.paramfloatnullablep(s)[0/1]? p-value of the seeing regression (2)stat.fit.goodnessfloatnullablep(t)[0/1]? p-value of the regression on time (2)stat.fit.goodnessfloatnullableR2[-0.1/1]? Proportion of variance explained by the fit (2)stat.fit.paramfloatnullableZP? Zeropoint (3)mmagphot.magintnullableLCPlot of the light variations in this observationmeta.ref.urlcharFileNameName of the file in subdirectory photmeta.id;meta.filecharNameName as in table1meta.id;meta.mainchar