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

January 2011 • 2011ApJ...726...30M

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.

Abstract • 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 μm 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 μm. 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.


IPAC Authors

Chris Gelino

Associate Scientist


Davy Kirkpatrick

Senior Scientist