Related papers: The first spectroscopically confirmed brown dwarfs…
We present a new sample of mid L to mid T dwarfs with effective temperatures of 1100 to 1700K selected from the UKIDSS Large Area Survey and confirmed with infrared spectra from X-Shooter/VLT. This effective temperature range is especially…
We present the results of dust continuum and molecular line observations of two massive cluster-forming clumps, NGC 2264-C and NGC 2264-D, including extensive mapping performed with the MAMBO bolometer array and the HERA heterodyne array on…
A common proper motion survey of M dwarf stars within 8 pc of the Sun reveals no new stellar or brown dwarf companions at wide separations (~100-1400 AU). This survey tests whether the brown dwarf ``desert'' extends to large separations…
We present some results of a CFHT adaptive optics search for companions to nearby dwarfs. We identify 21 new components in solar neighbourhood systems, of which 13 were found while surveying a volume-limited sample of M dwarfs within 12pc.…
We observe 14 young low-mass substellar objects in young moving groups using the SINFONI IFS with LGS-AO to detect and characterize 3 candidate binary systems. Together with the adopted young moving group ages we employ isochrones from…
We confirm 66 low-mass stellar and brown dwarf systems (K7-M9) plus 19 visual or spectroscopic companions of the beta Pictoris Moving Group (BPMG). Of these, 41 are new discoveries, increasing the known low-mass members by 45%. We also add…
We investigate the low-mass population of the young cluster IC348 down to the deuterium-burning limit, a fiducial boundary between brown dwarf and planetary mass objects, using a new and innovative method for the spectral classification of…
While following up L dwarf candidates selected photometrically from the Two Micron All Sky Survey, we uncovered an unusual object designated 2MASS J01415823-4633574. Its optical spectrum exhibits very strong bands of vanadium oxide but…
In 2022, the James Webb Space Telescope (JWST) obtained 1-5um images of the center of the Orion Nebula Cluster (ONC). I have analyzed these data in an attempt to search for substellar members of the cluster. Using a pair of color-color…
We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter continuum survey to date. Under standard…
We present a study of the young (30-100Myr) open cluster IC 4665 with the aim to determine the shape of the mass function well into the brown dwarf regime. We photometrically select 691 low-mass stellar and 94 brown dwarf candidate members…
M dwarfs with masses 0.1 <= M/M_sol <= 0.3 are under increasing scrutiny because these fully convective stars pose interesting astrophysical questions regarding their magnetic activity and angular momentum history. They also afford the most…
We present the spectroscopic analysis of a large sample of late-M, L, and T dwarfs from UKIDSS. Using the YJHK photometry from ULAS and the red-optical photometry from SDSS we selected a sample of 262 brown dwarf candidates and we…
We present the results of a 6.4 square degrees imaging survey of the Pleiades cluster in the I and Z-bands. The survey extends up to 3 degrees from the cluster center and is 90% complete down to I~22. It covers a mass range from 0.03 Msun…
Aims. Measuring dynamical masses of substellar companions is a powerful tool to test models of mass-luminosity-age relations, as well as determining observational features that constrain the boundary between stellar and substellar…
We present the discovery of 11 new T dwarfs, found during the course of a photometric survey for mid-to-late T dwarfs in the 2MASS Point Source Catalog and from a proper motion selected sample of ultracool dwarfs in the 2MASS Working…
We present the results of a Hubble Space Telescope NICMOS imaging survey of 22 T-type field brown dwarfs. Five are resolved as binary systems with angular separations of 0"05-0"35, and companionship is established on the basis of component…
We report the discovery of a brown dwarf orbiting a M1 host star. We first identified the brown dwarf within the Next Generation Transit Survey data, with supporting observations found in TESS sectors 11 and 38. We confirmed the discovery…
Star formation theories are currently divergent regarding the fundamental physical processes that dominate the substellar regime. Observations of nearby young open clusters allow the brown dwarf (BD) population to be characterised down to…
We quantify the spatial distribution of stars for two subclusters centred around the massive/intermediate mass stars S Mon and IRS1/2 in the NGC2264 star-forming region. We find that both subclusters are have neither a substructured, nor a…