A T8.5 BROWN DWARF MEMBER OF THE xi URSAE MAJORIS SYSTEM

作者：Wright Edward L^*; Skrutskie M F; Kirkpatrick J Davy; Gelino Christopher R; Griffith Roger L; Marsh Kenneth A; Jarrett Tom; Nelson M J; Borish H J; Mace Gregory; Mainzer Amanda K; Eisenhardt Peter R; McLean Ian S; Tobin John J; Cushing Michael C

来源：Astronomical Journal, 2013, 145(3): 84.

DOI：10.1088/0004-6256/145/3/84

• brown dwarfs
• infrared: stars
• solar neighborhood
• stars: late-type
• stars: low-mass

The Wide-field Infrared Survey Explorer has revealed a T8.5 brown dwarf (WISE J111838.70+312537.9) that exhibits common proper motion with a solar-neighborhood (8 pc) quadruple star system-xi Ursae Majoris. The angular separation is 8%26apos;.5, and the projected physical separation is approximate to 4000 AU. The sub-solar metallicity and low chromospheric activity of xi UMa A argue that the system has an age of at least 2 Gyr. The infrared luminosity and color of the brown dwarf suggests the mass of this companion ranges between 14 and 38 M-J for system ages of 2 and 8 Gyr, respectively.

• 出版日期2013-3