Related papers: Precipitating Condensation Clouds in Substellar At…
A number of transiting exoplanets have featureless transmission spectra that might suggest the presence of clouds at high altitudes. A realistic cloud model is necessary to understand the atmospheric conditions under which such…
The precipitation of cloud particles in brown dwarf and exoplanet atmospheres establishes an ongoing downward flux of condensable elements. To understand the efficiency of cloud formation, it is therefore crucial to quantify the…
We developed a simple, physical and self-consistent cloud model for brown dwarfs and young giant exoplanets. We compared different parametrisations for the cloud particle size, by either fixing particle radii, or fixing the mixing…
We present a new two-dimensional, bin-scheme microphysical model of cloud formation in the atmospheres of hot Jupiters that includes the effects of longitudinal gas and cloud transport. We predict cloud particle size distributions as a…
Clouds of metal-bearing condensates play a critical role in shaping the emergent spectral energy distributions of the coolest classes of low-mass stars and brown dwarfs, L and T dwarfs. Because condensate clouds in planetary atmospheres…
Because the opacity of clouds in substellar mass object (SMO) atmospheres depends on the composition and distribution of particle sizes within the cloud, a credible cloud model is essential for accurately modeling SMO spectra and colors. We…
We aim at understanding the formation of cloud layers in quasi-static substellar atmospheres. The time-dependent description presented in (Helling & Woitke 2006) is a kinetic model describing nucleation, growth and evaporation. It is…
The large scale structure of a brown dwarf atmosphere is determined by an interplay of convection, radiation, dust formation, and gravitational settling, which possibly provides an explanation for the observed variability. The result is an…
Most brown dwarfs have atmospheres with temperatures cold enough to form clouds. A variety of materials likely condense, including refractory metal oxides and silicates; the precise compositions and crystal structures of predicted cloud…
Condensation clouds in substellar atmospheres have been widely inferred from spectra and photometric variability. Up until now, their horizontally averaged vertical distribution and mean particle size have been largely characterized using…
Numerous observational evidence has suggested the presence of active meteorology in the atmospheres of brown dwarfs. A near-infrared brightness variability has been observed. Clouds have a major role in shaping the thermal structure and…
The atmosphere of a brown dwarf or extrasolar giant planet controls the spectrum of radiation emitted by the object and regulates its cooling over time. While the study of these atmospheres has been informed by decades of experience…
Observations of brown dwarfs and relatively isolated young extrasolar giant planets have provided unprecedented details to probe atmospheric dynamics in a new regime. Questions about mechanisms governing global circulation remain to be…
Clouds seem like an every-day experience. But -- do we know how clouds form on brown dwarfs and extra-solar planets? How do they look like? Can we see them? What are they composed of? Cloud formation is an old-fashioned but still…
We present results from conducting a theoretical chemical analysis of a sample of benchmark companion brown dwarfs whose primary star is of type F, G or K. We summarize the entire known sample of these types of companion systems, termed…
A sophisticated approach to condensate opacity is required to properly model the atmospheres of L and T dwarfs. Here we review different models for the treatment of condensates in brown dwarf atmospheres. We conclude that models which…
Ground-based and spacecraft telescopic observations, combined with an intensive modeling effort, have greatly enhanced our understanding of hot giant planets and brown dwarfs over the past ten years. Although these objects are all fluid,…
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 K,…
A test case comparison is presented for different dust cloud model approaches applied in brown dwarfs and giant gas planets. We aim to achieve more transparency in evaluating the uncertainty inherent to theoretical modelling. We show in how…
We calculate the formation of dust clouds in atmospheres of giant gas-planets. The chemical structure and the evolution of the grain size distribution in the dust cloud layer is discussed based on a consistent treatment of seed formation,…