文章基本信息

标题：The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax Survey of L0–T8 Dwarfs with UKIRT
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作者：William M.J.Best ; Michael C.Liu ; Eugene A.Magnier 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2020
卷号：159
期号：6
页码：3555-3581
DOI：10.3847/1538-3881/ab84f4
语种：English
出版社：American Institute of Physics
摘要：We present parallaxes, proper motions, and J-band photometry for 348 L and T dwarfs measured using the wide-field near-infrared camera WFCAM on the United Kingdom Infrared Telescope.This is the largest single batch of infrared parallaxes for brown dwarfs to date.Our parallaxes have a median uncertainty of 3.5 mas, similar to most previous ground-based infrared parallax surveys.Our target list was designed to complete a volume-limited parallax sample of L0–T8 dwarfs out to 25 pc spanning declinations −30° to +60° (68% of the sky).We report the first parallaxes for 165 objects, and we improve on previous measurements for another 53 objects.Our targets include 104 objects (mostly early-L dwarfs) having Gaia DR2 parallax measurements with which our parallaxes are consistent.We include an extensive comparison of previous literature parallaxes for L and T dwarfs with both our results and Gaia DR2 measurements, identifying systematic offsets for some previous surveys.Our parallaxes confirm that 14 objects previously identified as wide common proper motion companions to main-sequence stars have distances consistent with companionship.We also report new ${J}_{\mathrm{MKO}}$ photometry for our targets, including the first measurements for 193 of our targets and improvements over previously published ${J}_{\mathrm{MKO}}$ photometry for another 60 targets.Altogether, our parallaxes will enable the first population studies using a volume-limited sample spanning spectral types L0–T8 defined entirely by parallaxes.
关键词：Late-type dwarf stars;Parallax;Proper motions;Infrared photometry;Trigonometric parallax;L dwarfs;T dwarfs