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The Gaia Ultra-Cool Dwarf Sample -- II : Structure at the end of the main sequence
(2019-05-01)
We identify and investigate known late M, L, and T dwarfs in the Gaia second data release. This sample is being used as a training set in the Gaia data processing chain of the ultracool dwarfs work package. We find 695 ...
A candidate super-Earth planet orbiting near the snow line of Barnard's star
(2018-11-15)
Barnard’s star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs, it is the closest single star to the Sun; only the three stars in the α ...
Primeval very low-mass stars and brown dwarfs - III. The halo transitional brown dwarfs
(2018-09-01)
We report the discovery of an esdL3 subdwarf, ULAS J020858.62+020657.0 and a usdL4.5 subdwarf, ULAS J230711.01+014447.1. They were identified as L subdwarfs by optical spectra obtained with the Gran Telescopio Canarias, ...
Surprisingly different starspot distributions on the near equal-mass equal-rotation-rate stars in the M dwarf binary GJ 65 AB
(2017-10-11)
We aim to understand how stellar parameters such as mass and rotation impact the distribution of starspots on the stellar surface. To this purpose, we have used Doppler imaging to reconstruct the surface brightness ...
Ultracool dwarf benchmarks with \emph{Gaia} primaries
(2017-10-01)
We explore the potential of \emph{Gaia} for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool ...
The Gaia Ultracool Dwarf Sample. I. Known L and T dwarfs and the first Gaia data release
(2017-07-01)
We identify and investigate known ultracool stars and brown dwarfs that are being observed or indirectly constrained by the Gaia mission. These objects will be the core of the Gaia ultracool dwarf sample composed of all ...
Low-resolution near-infrared spectroscopic signatures of unresolved ultracool companions to M dwarfs
(2017-06-01)
We develop a method to identify the spectroscopic signature of unresolved L-dwarf ultracool companions, which compares the spectra of candidates and their associated control stars using spectral ratio differences and ...
Parallaxes and Infrared Photometry of three Y0 dwarfs
(2017-03-24)
We have followed up the three Y0 dwarfs WISEPA J041022.71+150248.5, WISEPA J173835.53+273258.9 and WISEPC J205628.90+145953.3 using the UKIRT/WFCAM telescope/instruments. We find parallaxes that are more consistent and ...
VVV High proper motion stars I. The catalogue of bright Ks stars
(2017-01-01)
Knowledge of the stellar content near the Sun is important for a broad range of topics ranging from the search for planets to the study of Milky Way structure. The most powerful method for identifying potentially nearby ...