Related papers: Variability of Brown Dwarfs
A variety of observational evidence demonstrates that brown dwarfs exhibit active atmospheric circulations. In this study we use a shallow-water model to investigate the global atmospheric dynamics in the stratified layer overlying the…
Heterogeneous clouds or temperature perturbations in rotating brown dwarfs produce variability in the observed flux. We report time-resolved simultaneous observations of the variable T6.5 brown dwarf 2MASSJ22282889-431026 over the…
There is growing evidence that brown dwarfs may be comparable to main-sequence stars in terms of their abundance. In this paper, we explore the prospects for the existence of life on Earth-like planets around brown dwarfs. We consider the…
Carbon monoxide and ammonia have been detected in the spectrum of Gl 229B at abundances that differ substantially from those obtained from chemical equilibrium. Vertical mixing in the atmosphere is a mechanism that can drive slowly reacting…
One of the mechanisms suggested for the L to T dwarf spectral type transition is the appearance of relatively cloud-free regions across the disk of brown dwarfs as they cool. The existence of partly cloudy regions has been supported by…
Brown dwarfs, being transitional objects between giant planets and low-mass stars, possess dense, cool interiors that provide optimal conditions to explore non-standard physics. Capture and accumulation of dark-matter particles can alter…
Brown dwarfs and giant gas planets are substellar objects whose spectral appearance is determined by the chemical composition of the gas and the solids/liquids in the atmosphere. Atmospheres of substellar objects possess two major scale…
We have used an innovative tuneable filter technique to carry out a search for the variability signatures of meterological processes in the atmospheres of two nearby brown dwarfs. We find no evidence for variability in the L-type brown…
We review the current state of observational work on the formation of brown dwarfs, focusing on their initial mass function, velocity and spatial distributions at birth, multiplicity, accretion, and circumstellar disks. The available…
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,…
We have undertaken a series of hydrodynamic + N-body simulations in order to explore the properties of young stars. Our results suggest that the IMF may be sensitive to environment in its substellar region, with more brown dwarfs being…
Up to now, most planet search projects have concentrated on F to K stars. In order to considerably widen the view, we have stated a survey for planets of old, nearby brown dwarfs and very low mass stars. Using UVES, we have observed 26…
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 L/T transition is a critical evolutionary stage for brown dwarfs and self-luminous giant planets. L/T transition brown dwarfs are more likely to be spectroscopically variable, and their high-amplitude variability probes distributions in…
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…
Brown dwarfs are intermediate objects between planets and stars. The lower end of the brown-dwarf mass range overlaps with the one of massive planets and therefore the distinction between planets and brown-dwarf companions may require to…
We have observed the post common envelope binary WD0137-349 in the near infrared $J$, $H$ and $K$ bands and have determined that the photometry varies on the system period (116 min). The amplitude of the variability increases with…
As an exoplanet orbits its host star it reflects and emits light, forming a distinctive phase curve. By observing this light, we can study the atmosphere and surface of distant planets. The planets in our Solar System show a wide range of…
Large-amplitude variations are commonly observed in the atmospheres of directly imaged exoplanets and brown dwarfs. VHS 1256B, the most variable known planet-mass object, exhibits a near-infrared flux change of nearly 40%, with red color…
The recent discovery of photometric variations in L dwarfs has opened a discussion on the cause of the variations. We argue against the existence of magnetic spots in these atmospheres and favor the idea that non-uniform condensate coverage…