Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun
Abstract
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 Telescope, I have measured a proper motion of 8.1 ± 0.1'' yr-1 and a parallax of 0.454 ± 0.045'' (2.20^{+0.24}_{-0.20} pc) for WISE J085510.83-071442.5, giving it the third highest proper motion and the fourth largest parallax of any known star or brown dwarf. It is also the coldest known brown dwarf based on its absolute magnitude at 4.5 μm and its color in [3.6]-[4.5]. By comparing M 4.5 with the values predicted by theoretical evolutionary models, I estimate an effective temperature of 225-260 K and a mass of 3-10 M Jup for the age range of 1-10 Gyr that encompasses most nearby stars.
Based on data from the Wide-field Infrared Survey Explorer, the Spitzer Space Telescope, Gemini Observatory, and the VISTA Telescope at ESO's Paranal Observatory.- Publication:
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The Astrophysical Journal
- Pub Date:
- May 2014
- DOI:
- 10.1088/2041-8205/786/2/L18
- arXiv:
- arXiv:1404.6501
- Bibcode:
- 2014ApJ...786L..18L
- Keywords:
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- brown dwarfs;
- infrared: stars;
- proper motions;
- solar neighborhood;
- stars: low-mass;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Astrophys.J.786(2014)L18