Dust in brown dwarfs: I. Dust formation under turbulent conditions on microscopic scales

Ch. Helling, M. Oevermann, M. J. H. Lüttke, R. Klein and E. Sedlmayr

Astronomy & Astrophysics, 376, 194-212 (2001)

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Abstract:

Dust formation in turbulent media is studied adopting the example of brown dwarf atmospheres. By combining asymptotic techniques and time-dependent, multi-dimensional numerical simulations, we show that acoustic waves originating from convective motions provide a mechanism to initiate dust nucleation in otherwise dust-hostile environments. The subsequently growing particles cause a radiative cooling strong enough to re-initiate efficient dust formation resulting in a strongly inhomogeneous distribution of dust in such environments. Recent observations bear indications for such cloudy dust distributions in brown dwarf atmospheres.