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A T8.5 Brown Dwarf Member of the ξ Ursae Majoris System

Wright, Edward L. and Skrutskie, M. F. and Kirkpatrick, J. Davy and Gelino, Christopher R. and Griffith, Roger L. and Marsh, Kenneth A. and Jarrett, Tom and Nelson, M. J. and Borish, H. J. and Mace, Gregory and Mainzer, Amanda K. and Eisenhardt, Peter R. and McLean, Ian S. and Tobin, John J. and Cushing, Michael C. (2013) A T8.5 Brown Dwarf Member of the ξ Ursae Majoris System. Astronomical Journal, 145 (3). Art. No. 84. ISSN 0004-6256.

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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—ξ Ursae Majoris. The angular separation is 8.'5, and the projected physical separation is ≈4000 AU. The sub-solar metallicity and low chromospheric activity of ξ 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.

Item Type:Article
Related URLs:
URLURL TypeDescription
Wright, Edward L.0000-0001-5058-1593
Kirkpatrick, J. Davy0000-0003-4269-260X
Marsh, Kenneth A.0000-0003-0107-7803
Mace, Gregory0000-0001-7875-6391
Tobin, John J.0000-0002-6195-0152
Cushing, Michael C.0000-0001-7780-3352
Additional Information:© 2013 American Astronomical Society. Received 2012 March 26; accepted 2013 January 27; published 2013 February 14. This publication makes use of data products from the Widefield Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This work was partially supported by a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. Part of the data presented herein were obtained at the W. M. Keck Observatory from telescope time allocated to the National Aeronautics and Space Administration through the agency’s scientific partnership with the California Institute of Technology and the University of California. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Facilities: WISE, FMO:31in (FanCam), LBT (LUCIFER), Hale (TripleSpec), SO:Kuiper (2MASS), WIYN (WIRC), Keck:II (NIRC2-LGSAO)
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:brown dwarfs; infrared: stars; solar neighborhood; stars: late-type; stars: low-mass
Issue or Number:3
Record Number:CaltechAUTHORS:20130403-084119725
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Official Citation:A T8.5 Brown Dwarf Member of the ξ Ursae Majoris System Edward L. Wright et al. 2013 The Astronomical Journal 145 84
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:37734
Deposited By: Ruth Sustaita
Deposited On:03 Apr 2013 16:03
Last Modified:09 Mar 2020 13:19

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