منابع مشابه
Parallaxes of L and T dwarfs
We discuss a new program to measure the parallaxes of a number of L and T dwarfs, objects that bridge the gap between M dwarfs and planets. This pilot project tests the feasibility of using large telescopes with infrared detectors to determine parallaxes at the level of milli-arcseconds (mas). First results show that we are able to achieve the required centroiding precision and simulations indi...
متن کاملInfrared Parallaxes for Methane T Dwarfs
We report final results from our 2.5 year infrared parallax program carried out with the European Southern Observatory 3.5m New Technology Telescope and the SOFI infrared camera. Our program targeted precision astrometric observations of ten T type brown dwarfs in the J band. Full astrometric solutions (including trigonometric parallaxes) for nine T dwarfs are provided along with proper motion ...
متن کاملParallaxes of five L Dwarfs with a Robotic Telescope
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 spectral type versus absolute magnitude diagram, we do not find any evidence for binaries among our sample, or, at least no comparable mass binaries. Their spa...
متن کاملModeling Brown Dwarfs , L Dwarfs , and T Dwarfs
In this contribution, I touch on a subset of our recent efforts in spectral and opacity modeling aimed at improving our understanding of brown dwarfs, L dwarfs, and T dwarfs. I discuss theoretical calculations of the alkali line profiles, newly generated CrH opacities, new evidence for refractory rainout in T dwarfs from optical spectral measurements, and the distinction between brown dwarfs an...
متن کاملObservations of M , L , and T Dwarfs
We present the first mid-infrared spectra of brown dwarfs, together with observations of a low-mass star. Our targets are the M3.5 dwarf GJ 1001A, the L8 dwarf DENIS-P J0255−4700, and the T1/T6 binary system ǫ Indi Ba/Bb. As expected, the mid-infrared spectral morphology of these objects changes rapidly with spectral class due to the changes in atmospheric chemistry resulting from their differi...
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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2004
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921305001584