2010/10/21 by Ch. Helling, M. Jardine, S. Witte +1 · 74 citations
Physics and Astronomy · #Astro and Planetary Science #Astrobiology #Astronomy #Astrophysics #Atmosphere (unit) #Brown dwarf #Electron #Exoplanet #Gas giant #Ion #Ionization #Ionosphere and magnetosphere dynamics #Meteorology #Physics #Planet #Solar and Space Plasma Dynamics #astro-ph.EP
paper · pdf · doi:10.1088/0004-637x/727/1/4
published in The Astrophysical Journal 727(1), 4 (IOP Publishing) · 18 pages in referee's style, 5 figures, Acccepted by ApJ
arxiv created 2010/10/21 · openalex publication_date 2010/12/22 · arxiv updated 2015/05/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Brown dwarf and extrasolar planet atmospheres form clouds which strongly influence the local chemistry and physics. These clouds are globally neutral obeying dust–gas charge equilibrium which is, on short timescales, inconsistent with the observation of stochastic ionization events of the solar system planets. We argue that a significant volume of the clouds in brown dwarfs and extrasolar planets is susceptible to local discharge events. These are electron avalanches triggered by charged dust grains. Such intra-cloud discharges occur on timescales shorter than the time needed to neutralize the dust grains by collisional processes. An ensemble of discharges is likely to produce enough free charges to suggest a partial and stochastic coupling of the atmosphere to a large-scale magnetic field.