A global cloud map of the nearest known brown dwarf.
Brown dwarfs--substellar bodies more massive than planets but not massive enough to initiate the sustained hydrogen fusion that powers self-luminous stars--are born hot and slowly cool as they age. As they cool below about 2,300 kelvin, liquid or crystalline particles composed of calcium aluminates, silicates and iron condense into atmospheric 'dust', which disappears at still cooler temperatures (around 1,300 kelvin). Models to explain this dust dispersal include both an abrupt sinking of the entire cloud deck into the deep, unobservable atmosphere and breakup of the cloud into scattered patches (as seen on Jupiter and Saturn). However, hitherto observations of brown dwarfs have been limited to globally integrated measurements, which can reveal surface inhomogeneities but cannot unambiguously resolve surface features. Here we report a two-dimensional map of a brown dwarf's surface that allows identification of large-scale bright and dark features, indicative of patchy clouds. Monitoring suggests that the characteristic timescale for the evolution of global weather patterns is approximately one day.
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Crossfield
1] Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany [2] Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK.
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Biller
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Schlieder
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Deacon
1] Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany [2] UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) UMR 5274, 38041 Grenoble, France.
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Bonnefoy
CRAL-ENS, 46 Allée d'Italie, 69364 Lyon, Cedex 07, France.
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Homeier
CRAL-ENS, 46 Allée d'Italie, 69364 Lyon, Cedex 07, France.
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Allard
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Buenzli
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Henning
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Brandner
Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
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Goldman
1] Max Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany [2] International Max-Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg, Königstuhl 17, 69117 Heidelberg, Germany.
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Kopytova