We report the discovery of a bright ( J = 13.83 \pm 0.03 ) methane brown dwarf , or T dwarf , by the Two Micron All Sky Survey .
This object , 2MASSI J0559191-140448 , is the first brown dwarf identified by the newly commissioned CorMASS instrument mounted on the Palomar 60-inch Telescope .
Near-infrared spectra from 0.9 - 2.35 \micron show characteristic CH _ { 4 } bands at 1.1 , 1.3 , 1.6 , and 2.2 \micron , which are significantly shallower than those seen in other T dwarfs discovered to date .
Coupled with the detection of an FeH band at 0.9896 and two sets of K I doublets at J-band , we propose that 2MASS J0559-14 is a warm T dwarf , close to the transition between L and T spectral classes .
The brightness of this object makes it a good candidate for detailed investigation over a broad wavelength regime and at higher resolution .