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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 focus on L dwarfs with trigonometric parallaxes
(2018-05-14)
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 ...
In-depth study of moderately young but extremely red, very dusty substellar companion HD206893B
(2017-12-08)
The substellar companion HD206893b has recently been discovered by direct imaging of its disc-bearing host star with the SPHERE instrument. We investigate the atypical properties of the companion, which has the reddest ...
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 ...
Infrared spectroscopy of eruptive variable protostars from VVV
(2017-03-01)
In a companion work (Paper I) we detected a large population of highly variable Young Stellar Objects (YSOs) in the Vista Variables in the Via Lactea (VVV) survey, typically with class I or flat spectrum spectral energy ...
A large spectroscopic sample of L and T dwarfs from UKIDSS LAS : peculiar objects, binaries, and space density
(2015-06-01)
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 ...
The Properties of the 500 K Dwarf UGPS J072227.51-054031.2, and a Study of the Far-Red Flux of Cold Brown Dwarfs
(2012-04-01)
We present i and z photometry for 25 T dwarfs and one L dwarf. Combined with published photometry, the data show that the i - z, z - Y and z - J colors of T dwarfs are very red, and continue to increase through to the ...