Direct Imaging at 12microns of the Star Forming Region W51 IRS 2.

We have made direct imaging observations of the luminous star forming region W51 IRS 2 with the 10 by 64 pixel Berkeley direct readout infrared camera. Using the Steward Observatory 90" reflector at 12microns, we mosaicked 4 adjacent fields to obtain a 2500 pixel map with a pixel size of 0.4" and a resolution better than 1". The distribution of the 12microns emission shows a symmetric "dumbbell" in which the central and brightest structure is about 4" by 1" in size. The observed surface brightness is consistent with optically thick 12micron emission from dust at radiative equilibrium with a 3 x 10 sup 6 L(solar) central source. These results suggest that W51 IRS 2 is a hot (T = 110 K), very dense (n >= 10 sup 7 cm (-3) ) massive disk (of order 100 - 200 M (solar) ) surrounding a very luminous and massive protostellar source.