The First Ultra-cool Brown Dwarf Discovered by the Wide-field Infrared Survey Explorer

• Published in: The Astrophysical journal Vol. 726; no. 1; pp. 30 - jQuery1323912172192='48'
• Main Authors: Mainzer, A, Cushing, Michael C, Skrutskie, M, Gelino, C. R, Kirkpatrick, J. Davy, Jarrett, T, Masci, F, Marley, Mark S, Saumon, D, Wright, E, Beaton, R, Dietrich, M, Eisenhardt, P, Garnavich, P, Kuhn, O, Leisawitz, D, Marsh, K, McLean, I, Padgett, D, Rueff, K
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.01.2011; IOP
• Subjects: Astronomy; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Binoculars; DIMENSIONLESS NUMBERS; Earth, ocean, space; Exact sciences and technology; GEOLOGIC SURVEYS; GEOPHYSICAL SURVEYS; INFRARED SURVEYS; SIGNAL-TO-NOISE RATIO; Space telescopes; Spaceborne telescopes; Spectra; STARS; Sun; Temperature; Wide-field Infrared Survey Explorer; Spectroscopy; Late type stars; Mixing; Atmosphere model; infrared: stars; Effective temperature; Signal-to-noise ratio; Spectral type; Sun; Infrared surveys; brown dwarfs; stars: late-type; Low-mass stars; Brown dwarf stars; Solar neighborhood; stars: low-mass; Infrared star
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/726/1/30

We report the discovery of the first new ultra-cool brown dwarf (BDs) found with the Wide-field Infrared Survey Explorer (WISE). The object's preliminary designation is WISEPC J045853.90+643451.9. Follow-up spectroscopy with the LUCIFER instrument on the Large Binocular Telescope indicates that it is a very late-type T dwarf with a spectral type approximately equal to T9. Fits to an IRTF/SpeX 0.8-2.5 Delta *mm spectrum to the model atmospheres of Marley and Saumon indicate an effective temperature of approximately 600 K as well as the presence of vertical mixing in its atmosphere. The new BD is easily detected by WISE, with a signal-to-noise ratio of ~36 at 4.6 Delta *mm. Current estimates place it at a distance of 6-10 pc. This object represents the first in what will likely be hundreds of nearby BDs found by WISE that will be suitable for follow-up observations, including those with the James Webb Space Telescope. One of the two primary scientific goals of the WISE mission is to find the coolest, closest stars to our Sun; the discovery of this new BD proves that WISE is capable of fulfilling this objective.