相关论文: The Future of Ultracool Dwarf Science with JWST
Photometric I band light curves of 21 ultra cool M and L dwarfs are presented. Variability with amplitudes of 0.01 to 0.055 magnitudes (RMS) with typical timescales of an hour to several hours are discovered in half of these objects.…
One of the main scientific drivers of the Space InfraRed Telescope Facility (SIRTF) is the search for brown dwarfs and extrasolar superplanets. We discuss observational strategies for identification of these objects, and conclude that an…
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…
We report the discovery of twenty-one hitherto unknown bright southern ultracool dwarfs with spectral types in the range M7 to L5.5, together with new observations of a further three late M dwarfs previously confirmed. Three more objects…
We advocate for the prioritization of high-precision photometric monitoring of exoplanet and brown dwarf companions to detect brightness variability arising from features in their atmospheres. Measurements of photometric variability provide…
Observations of brown dwarfs provide important feedback on theories of atmospheres and inner structure of substellar objects. Brown dwarf binary systems furthermore offer the unique opportunity to determine the mass of individual brown…
We advocate for further prioritisation of atmospheric characterisation observations of high mass transiting exoplanets and brown dwarfs. This population acts as a unique comparative sample to the directly imaged exoplanet and brown dwarf…
We selected brown dwarf candidates from the seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7) with new photometric selectioncriteria based on a parameteriaztion of well-known L and T dwarfs. Then we confirmed their status with…
White dwarfs are the final remnants of low- and intermediate-mass stars. Their evolution is essentially a cooling process that lasts for $\sim 10$ Gyr. Their observed properties provide information about the history of the Galaxy, its dark…
We present infrared spectral energy distributions of 23 late-type T and Y dwarfs obtained with the James Webb Space Telescope. The spectral energy distributions consist of NIRSpec PRISM and MIRI LRS spectra covering the $\sim$1--12 $\mu$m…
We associate 132 low-mass ultracool dwarfs in the southern hemisphere as candidate members of five moving groups using photometric and astrometric selection techniques. Of these objects, we present high resolution spectroscopy for seven…
I review the optical and near-infrared spectral characteristics of the extremely cool dwarfs grouped under the new classification of type L. These include both very low-mass stars and brown dwarfs, and we discuss the likely temperature…
The James Webb Space Telescope (JWST) will allow observations with a unique combination of spectral, spatial, and temporal resolution for the study of outer planet satellites within our Solar System. We highlight the infrared spectroscopy…
White dwarfs, the most abundant stellar remnants, provide a promising means of probing dark matter (DM) interactions, complimentary to terrestrial searches. The scattering of dark matter from stellar constituents leads to gravitational…
We present the first JWST spectral energy distribution of a Y dwarf. This spectral energy distribution of the Y0 dwarf WISE J035934.06$-$540154.6 consists of low-resolution ($\lambda$/$\Delta\lambda$ $\sim$ 100) spectroscopy from 1$-$12…
The James Webb Space Telescope (JWST) is predicted to make great advances in the field of exoplanet atmospheres. Its 25 m2 mirror means that it can reach unprecedented levels of precision in observations of transit spectra, and can thus…
We compare properties of high-redshift galaxies observed by JWST with hydrodynamical simulations, in the standard cold dark matter model and in warm dark matter models with a suppressed linear matter power spectrum. We find that current…
The L/T transition is an important evolutionary phase in brown dwarf atmospheres, providing us with a unique opportunity to explore the effects of clouds, convection, winds, gravity and metallicity across a very narrow temperature range.…
Context: L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into unresolved atmospheric heterogeneities, such…
The white dwarf luminosity function, which provides information about their cooling, has been measured with high precision in the past few years. Simulations that include well known Standard Model physics give a good fit to the data. This…