Gliese 229B.  
This type of object was the subject of the thesis of Jill Tarter, who coined the name.  One major project of the WISE satellite is searching for these objects, whose namesake "desert" refers to their absence in relatively tight binaries.  One of the diagnostic tests for them is emission lines of (*) lithium, and their T class, which shows absorption bands due to methane, is exemplified by the first known one of these objects, Gliese 229B.  They are fully convective and typically exhibit a brief deuterium fusion phase, but do not enter the main sequence due to their inability to ignite hydrogen. For 10 points, name these small objects sometimes described as "failed stars."
This type of object was the subject of the thesis of Jill Tarter, who coined the name.  
{brown dwarves}