Related papers: Predicting Cloud Conditions in Substellar Mass Obj…
Cold brown dwarfs are excellent analogs of widely separated, gas giant exoplanets, and provide insight into the potential atmospheric chemistry and physics we may encounter in objects discovered by future direct imaging surveys. We present…
Clouds form in atmospheres of brown dwarfs and planets. The cloud particle formation processes are similar to the dust formation process studied in circumstellar shells of AGB stars and in Supernovae. Cloud formation modelling in substellar…
Y dwarfs are the coolest spectral class of brown dwarf. They have effective temperatures less than 500 K, with the coolest detection as low as ~250 K. Their spectra are shaped predominantly by gaseous water, methane, and ammonia. At the…
Analysis of initial observations from near-infrared sky surveys has shown that the resulting photometric catalogues, combined with far-red optical data, provide an extremely effective method of finding isolated, very low-temperature objects…
Understanding demographic properties of planet populations and multiple star systems constrains theories of planet and star formation. Surveys for very low-mass companions to M-A type stars detect brown dwarfs from multiple star formation…
We present a method to select hot subdwarf stars with A to M-type companions using photometric selection criteria. We cover a wide range in wavelength by combining GALEX ultraviolet data, optical photometry from the SDSS and the Carlsberg…
Emerging research suggests that elemental and isotopic ratios of exoplanet and brown dwarf atmospheres may serve as potential tracers of their formation pathways. The ESO SupJup Survey aims to shed light on this hypothesis, with a focus on…
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…
The formation of clouds affects brown dwarf and planetary atmospheres of nearly all effective temperatures. Iron and silicate condense in L dwarf atmospheres and dissipate at the L/T transition. Minor species such as sulfides and salts…
In this first of a two-paper sequence, we report techniques and results of the Cornell High-order Adaptive Optics Survey for brown dwarf companions (CHAOS). At the time of this writing, this study represents the most sensitive published…
We investigate the formation of binary stellar systems. We consider a model where a `seed' protobinary system forms, via fragmentation, within a collapsing molecular cloud core and evolves to its final mass by accreting material from an…
Brown dwarfs are essential targets for understanding planetary and sub-stellar atmospheres across a wide range of thermal and chemical conditions. As surveys continue to probe ever deeper, and as observing capabilities continue to improve,…
The atmospheres of brown dwarfs orbiting in close proximity to their parent white dwarf represent some of the most extreme irradiated environments known. Understanding their complex dynamical mechanisms pushes the limits of theoretical and…
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 recent model for the stellar initial mass function (IMF), in which the stellar masses are randomly sampled down to the thermal Jeans mass from hierarchically structured pre-stellar clouds, predicts that regions of ultra-cold CO gas, such…
We present results from a high-resolution, cosmological, $\Lambda$CDM simulation of a group of field dwarf galaxies with the "superbubble" model for clustered SN feedback, accounting for thermal conduction and cold gas evaporation. The…
We show that the total habitable volume in the atmospheres of cool brown dwarfs with effective temperatures of $\sim 250$-$350$ K is possibly larger by two orders of magnitude than that of Earth-like planets. We also study the role of…
Bayesian atmospheric retrieval tools can place constraints on the properties of brown dwarfs and hot Jupiters atmospheres. To fully exploit these methods, high signal-to-noise spectral libraries with well-understood uncertainties are…
We combine results from imaging searches for substellar objects in the sigma Orionis cluster and follow-up photometric and spectroscopic observations to derive a census of the brown dwarf population in a region of 847 arcmin^2. We identify…
The mass and age of substellar objects are degenerate parameters leaving the evolutionary state of brown dwarfs ambiguous without additional information. Theoretical models are normally used to help distinguish between old, massive brown…