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Title: WEATHER ON THE NEAREST BROWN DWARFS: RESOLVED SIMULTANEOUS MULTI-WAVELENGTH VARIABILITY MONITORING OF WISE J104915.57–531906.1AB

We present two epochs of MPG/ESO 2.2 m GROND simultaneous six-band (r'i'z' JHK) photometric monitoring of the closest known L/T transition brown dwarf binary WISE J104915.57–531906.1AB. We report here the first resolved variability monitoring of both the T0.5 and L7.5 components. We obtained 4 hr of focused observations on the night of 2013 April 22 (UT), as well as 4 hr of defocused (unresolved) observations on the night of 2013 April 16 (UT). We note a number of robust trends in our light curves. The r' and i' light curves appear to be anti-correlated with z' and H for the T0.5 component and in the unresolved light curve. In the defocused dataset, J appears correlated with z' and H and anti-correlated with r' and i', while in the focused dataset we measure no variability for J at the level of our photometric precision, likely due to evolving weather phenomena. In our focused T0.5 component light curve, the K band light curve displays a significant phase offset relative to both H and z'. We argue that the measured phase offsets are correlated with atmospheric pressure probed at each band, as estimated from one-dimensional atmospheric models. We also report low-amplitude variability in i'more » and z' intrinsic to the L7.5 component.« less
Authors:
; ; ; ; ; ; ; ; ; ; ; ;  [1] ;  [2] ; ; ;  [3] ;  [4]
  1. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
  2. Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom)
  3. Centre de Recherche Astrophysique de Lyon, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, F-69364 Lyon cedex 07 (France)
  4. Max-Planck Institute for extraterrestrische Physik, D-85748 Garching, Giessenbachstr (Germany)
Publication Date:
OSTI Identifier:
22364130
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 778; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; AMPLITUDES; ASTRONOMY; ASTROPHYSICS; ATMOSPHERIC PRESSURE; BINARY STARS; DATASETS; DIAGRAMS; DWARF STARS; MASS; PHOTOMETRY; PROBES; STARS; VISIBLE RADIATION; WAVELENGTHS