Related papers: L and T dwarfs in the Hyades and Ursa Major moving…
The proper motion measurements for 143 previously known L and T dwarfs are presented. From this sample we identify and discuss 8 high velocity L dwarfs. We also find 4 new wide common proper motion binaries/multiple systems. Using the…
By using images taken with WFCAM on UKIRT and SofI on the NTT and combining them with 2MASS we have measured proper motions for 126 L and T dwarfs in the dwarf archive. Two of these L dwarfs appear to have M dwarf common proper motion…
We present a new method to derive the age of young (<0.7 Gyr) L dwarfs based on their near-infrared photometry, colours, and distances. The method is based on samples of L dwarfs belonging to the Upper Sco association (5 Myr), the Alpha Per…
We present the results of a proper motion survey of the Hyades to search for brown dwarfs, based on UKIDSS and 2MASS data. This survey covers ~275 square degrees to depth of K~15 mag, equivalent to a mass of 0.05 solar masses assuming a…
We present the results of photometric, astrometric, and spectroscopic follow-up of L dwarf candidates identified in the Hyades cluster by Hogan et al. (2008). We obtained low-resolution optical spectroscopy with the OSIRIS spectrograph on…
We present an analysis of 23 L dwarfs whose optical spectra display unusual features. Twenty-one were uncovered during our search for nearby, late-type objects using the Two Micron All-Sky Survey while two were identified in the literature.…
We use Gaia DR2 kinematic data and white dwarf evolutionary models to determine that the young and ultramassive white dwarf GD 50 is a likely member of the AB Doradus moving group. Comparison with the Montr\'eal white dwarf evolutionary…
Young brown dwarfs share many properties with directly imaged giant extrasolar planets. They therefore provide unique laboratories for investigating the full range of temperature and mass encompasses by the growing collection of planets…
We have estimated the age of the young moving group TW Hydrae Association, a cohort of a few dozen stars and brown dwarfs located near the Sun which share the same kinematic properties and, presumably, the same origin and age. The…
The Hyades cluster is known to harbour ten so-called classical white dwarf members. Numerous studies through the years have predicted that more than twice this amount of degenerate stars should be associated with the cluster. Using the…
(Abridged) We aim to determine the trigonometric parallaxes and proper motions of a sample of ten field L0-L5 dwarfs with spectroscopic evidence for low-gravity atmospheres. We obtained J and Ks imaging data using 2-4-m class telescopes…
We use new and extant literature spectroscopy to address abundances and membership for UMa moving group stars. We first compare the UMa, Coma, and Hyades H-R diagrams via a homogeneous set of isochrones, and find that these three aggregates…
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…
The Ursa Major Moving Group (UMa) is one of the closest stellar associations, yet its age has remained controversial, with published estimates ranging from 200 Myr to 1 Gyr. We present a comprehensive age analysis using the largest sample…
We present a set of 5 over-densities in spatial-kinematic space previously identified by Kounkel & Covey (2019) that may constitute extended tidal tails associated with the nearby, 400-Myr old Ursa Major association. This sample of 1599…
We present a uniform forward-modeling analysis of 90 late-M and L dwarfs in nearby young (~$10-200$ Myr) moving groups, the Pleiades, and the Hyades using low-resolution ($R\approx150$) near-infrared ($0.9-2.4$ $\mathrm{\mu m}$) spectra and…
We report new parallax measurements for ten L and early T type dwarfs, five of which have no previous published values, using observations over 3 years at the robotic Liverpool Telescope. The resulting parallaxes and proper motions have…
We present a study of age-related spectral signatures observed in 25 young low-mass objects that we have previously determined as possible kinematic members of five young moving groups: the Local Association (Pleiades moving group, age=20 -…
Exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. Young planets ($<$1 Gyr) offer an opportunity to probe the critical early stages of this…
We present a self-consistent, absolute isochronal age scale for young (< 200 Myr), nearby (< 100 pc) moving groups in the solar neighbourhood based on homogeneous fitting of semi-empirical pre-main-sequence model isochrones using the tau^2…