相关论文: Cloud Formation and Dynamics in Cool Dwarf and Hot…
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…
The last few years has seen a dramatic increase in the number of exoplanets known and in the range of methods for characterising their atmospheric properties. At the same time, new discoveries of increasingly cooler brown dwarfs have pushed…
Brown dwarfs are massive, giant exoplanet analogues subject to variability and colour changes, known as the L/T transition, fundamental for their thermal evolution. The drivers of the L/T transition remain elusive, with atmospheric…
Brown dwarfs are commonly regarded as easily-observed templates for exoplanet studies, with comparable masses, physical sizes and atmospheric properties. There is indeed considerable overlap in the photospheric temperatures of the coldest…
Clouds and hazes are commonplace in the atmospheres of solar system planets and are likely ubiquitous in the atmospheres of extrasolar planets as well. Clouds affect every aspect of a planetary atmosphere, from the transport of radiation,…
Recent observations indicate potentially carbon-rich exoplanet atmospheres. Spectral fitting methods for brown dwarfs and exoplanets have invoked the C/O ratio as additional parameter but carbon-rich cloud formation modeling is a challenge…
Brown dwarfs bridge the gap between the stellar and planetary mass regimes. Evolving from conditions very similar to the lowest-mass stars, the atmospheres of older brown dwarfs closely resemble those expected in close-in extrasolar giant…
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…
The characterization of exoplanetary atmospheres has come of age in the last decade, as astronomical techniques now allow for albedos, chemical abundances, temperature profiles and maps, rotation periods and even wind speeds to be measured.…
The study of the composition of brown dwarf atmospheres helped to understand their formation and evolution. Similarly, the study of exoplanet atmospheres is expected to constrain their formation and evolutionary states. We use results from…
Hot giant exoplanets are very exotic objects with no equivalent in the Solar System that allow us to study the behavior of atmospheres under extreme conditions. Their thermal and chemical day--night dichotomies associated with extreme wind…
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…
This invited review for young researchers presents key ideas on cloud formation as key part for virtual laboratories for exoplanet atmospheres. The basic concepts are presented, followed by utilising a time-scale analysis to disentangle…
Clouds and hazes are important throughout our solar system and in the atmospheres of brown dwarfs and extrasolar giant planets. Among the brown dwarfs, clouds control the colors and spectra of the L-dwarfs; the disappearance of clouds helps…
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…
Warm Saturn type exoplanets orbiting M-dwarfs are particularly suitable for in-depth cloud characterisation through transmission spectroscopy due to their favourable stellar to planetary radius contrast. However, modelling cloud formation…
Brown dwarfs and giant gas extrasolar planets have cold atmospheres with a rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral…
With JWST slated to gain high fidelity time dependent data on brown dwarf atmospheres, it is highly anticipated to do the same for directly imaged, sub-Jupiter exoplanets. With this new capability, the need for a full 3D understanding to…
We review several aspects of the calculation of exoplanet model atmospheres in the current era, with a focus on understanding the temperature-pressure profiles of atmospheres and their emitted spectra. Most of the focus is on gas giant…
Context: Low-mass stars and extrasolar planets have ultra-cool atmospheres where a rich chemistry occurs and clouds form. The increasing amount of spectroscopic observations for extrasolar planets requires self-consistent model atmosphere…