ABSTRACT: Recent diffraction-limited K-band [2.2 micron ] imaging observations with the Keck 10-m telescope have unambiguously resolved, for the first time at this wavelength, the unusual cool stellar stellar sources IRS 21, 1W, and 10W. We have estimated the intrinsic sizes of these objects to be ~ 1000 AU, placing them among the largest stellar objects known. These measurements, along with modeling of their SEDs, lead us to conclude that these sources are self-luminous, composed of a central heating source and a surrounding dust shell. We will present both the images and detailed modeling of these sources.