相关论文: Parallaxes and Infrared Photometry of three Y0 dwa…

We present parallaxes of 11 mid-to-late T dwarfs observed in the UKIRT Infrared Deep Sky Survey. We use these results to test the reliability of model predictions in magnitude-color space, determine a magnitude-spectral type calibration,…

Y dwarfs provide a unique opportunity to study free-floating objects with masses $<$30 M$_{Jup}$ and atmospheric temperatures approaching those of known Jupiter-like exoplanets. Obtaining distances to these objects is an essential step…

Accurate parallax measurements allow us to determine physical properties of brown dwarfs, and help us to constrain evolutionary and atmospheric models, break the age-mass degeneracy and reveal unresolved binaries. We measured absolute…

We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multi-epoch photometry of L and early T dwarfs. The observations were made on 108 nights over the course of 8…

We report the parallax and proper motion of five L dwarfs obtained with observations from the robotic Liverpool Telescope. Our derived proper motions are consistent with published values and have considerably smaller errors. Based on our…

We measured absolute trigonometric parallaxes and proper motions with respect to many background galaxies for a sample of ten ultracool subdwarfs. The observations were taken in the H-band with the OMEGA2000 camera at the 3.5m-telescope on…

Trigonometric parallax determinations are presented for 28 late type dwarfs and brown dwarfs, including eight M dwarfs with spectral types between M7 and M9.5, 17 L dwarfs with spectral types between L0 and L8, and three T dwarfs. Broadband…

We present YJHK photometry, or a subset, for the six Y dwarfs discovered in WISE data by Cushing et al.. The data were obtained using NIRI on the Gemini North telescope. We also present a far-red spectrum obtained using GMOS-North for…

We present new near-infrared spectra, obtained at Gemini Observatory, for two Y dwarfs: WISE J035000.32-565830.2 (W0350) and WISEP J173835.52+273258.9 (W1738). A FLAMINGOS-2 R=540 spectrum was obtained for W0350, covering 1.0 < lambda um <…

We report the discovery of a wide pair (93 arcsec angular separation) of extremely cool ($T_{eff}<4000$ K) white dwarfs with a very large common proper motion ($\sim1.9$ arcsec/yr). The objects were discovered in a high proper motion survey…

We present results from the PARallaxes of Southern Extremely Cool objects (PARSEC) program, an observational program begun in April 2007 to determine parallaxes for 122 L and 28 T southern hemisphere dwarfs using the Wide Field Imager on…

We present preliminary trigonometric parallaxes and proper motions for 22 L dwarfs and 18 T dwarfs measured using the ASTROCAM infrared imager. Relative to absolute parallax corrections are made by employing 2MASS and/or SDSS photometry for…

Trigonometric parallaxes have been measured by Dahn et al. (2002) for 28 cool dwarfs and brown dwarfs, including 17 L dwarfs and three T dwarfs. Broadband CCD and near-IR photometry (VRIz*JHK) have been obtained for these objects and for 24…

Through a previous analysis of multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE), I identified WISE J085510.83-071442.5 as a new high proper motion object. By combining astrometry from WISE and the Spitzer Space…

We present near-infrared spectroscopy for 52 ultracool dwarfs, including two newly discovered late-M dwarfs, one new late-M subdwarf candidate, three new L and four new T dwarfs. We also present parallaxes and proper motions for 21 of them.…

Our goal is to characterise the physical properties of the metal-poor brown dwarf population. In particular, we focus on the recently discovered peculiar dwarf WISE J1810055$-$1010023. We collected optical iz and near-infrared J-band…

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 present near-infrared parallax and proper motion astrometry for 74 L-dwarfs and 99 T-dwarfs, as single objects or in binary systems, obtained with the ASTROCAM astrometric imager on the USNO, Flagstaff Station 1.55-m telescope over two…

AIMS: Using Wide-field Infrared Survey Explorer (WISE) data and previous optical and near-infrared sky surveys, we try to identify still missing stellar and substellar neighbours of the Sun. METHODS: When checking the brightest red WISE…

We present metallicity and photometric parallax calibrations for the F and G type dwarfs with photometric, astrometric and spectroscopic data. The sample consists of 168 dwarf stars covering the colour, iron abundance and absolute magnitude…