J/ApJ/832/58ivo://CDS.VizieR/J/ApJ/832/58doi:10.26093/cds/vizier.18320058CDSEsplin T.L.Luhman K.L.Cushing M.C.Hardegree-Ullman K.K.Trucks J.L.,Burgasser A.J.Schneider A.C.2017-06-30T05:48:07Z2017-03-16T14:26:06ZCDS support team

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

cds-question@unistra.frinfrared-photometrylate-type-starsBecause WISE J085510.83-071442.5 (hereafter WISE 0855-0714) is the coldest known brown dwarf (~250K) and one of the Sun's closest neighbors (2.2pc), it offers a unique opportunity to study a planet-like atmosphere in an unexplored regime of temperature. To detect and characterize inhomogeneities in its atmosphere (e.g., patchy clouds, hot spots), we have performed time-series photometric monitoring of WISE 0855-0714 at 3.6 and 4.5{mu}m with the Spitzer Space Telescope during two 23hr periods that were separated by several months. For both bands, we have detected variability with peak-to-peak amplitudes of 4%-5% and 3%-4% in the first and second epochs, respectively. The light curves are semiperiodic in the first epoch for both bands, but they are more irregular in the second epoch. Models of patchy clouds have predicted a large increase in mid-infrared (mid-IR) variability amplitudes (for a given cloud covering fraction) with the appearance of water ice clouds at T_eff_<375K, so if such clouds are responsible for the variability of WISE 0855-0714, then its small amplitudes of variability indicate a very small deviation in cloud coverage between hemispheres. Alternatively, the similarity in mid-IR variability amplitudes between WISE 0855-0714 and somewhat warmer T and Y dwarfs may suggest that they share a common origin for their variability (i.e., not water clouds). In addition to our variability data, we have examined other constraints on the presence of water ice clouds in the atmosphere of WISE 0855-0714, including the recent mid-IR spectrum from Skemer+ (2016ApJ...826L..17S). We find that robust evidence of such clouds is not yet available.2016ApJ...832...58Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/832/58CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/mk : Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)II/311 : WISE All-Sky Data Release (Cutri+ 2012)J/A+A/584/A104 : Luhman 16AB Lucky imaging photom. + astrometry (Mancini+ 2015)J/A+A/566/A111 : Brown dwarf atmosphere monitoring (BAM) (Wilson+, 2014)J/ApJ/781/4 : Photom. of high proper motion objects from WISE (Luhman, 2014)J/AJ/144/148 : IR photometry of brown dwarf and Hyper-LIRG (Griffith+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/832/58https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/832/58http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/832/58https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/832/58https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/832/58http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/832/58GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/832/58/table1Time-series Photometry for WISE 0855-0714 in [3.6]3.6mag[14.2/17.7] Spitzer/IRAC [3.6] micron band magnitudemagphot.mag;em.IR.3-4umfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHMJDHeliocentric Modified Julian Date (G1)dtime.epochdoublee_3.6mag[0.009/0.1] Error in 3.6magmagstat.errorfloatf_3.6mag[N/Y] Flagged as outlier in 3.6mag?meta.codecharJ/ApJ/832/58/table2Time-series Photometry for WISE 0855-0714 in [4.5]recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHMJDHeliocentric Modified Julian Date (G1)dtime.epochdouble4.5mag[13.3/14.8] Spitzer/IRAC [4.5] micron band magnitudemagphot.mag;em.IR.4-8umfloate_4.5mag[0.006/0.02] Error in 4.5magmagstat.errorfloatf_4.5mag[N/Y] Flagged as outlier in 4.5mag?meta.codechar