Program: GS-2007B-Q-222

We propose to obtain high angular resolution, mid-infrared images of transition disks identified with the Spitzer Space Telescope in the Orion and Chamaeleon star-forming regions. These transition disks are key objects for constraining the physical mechanisms responsible for disk evolution. However, this is complicated by the fact that most young stars have companions that would be unresolved in the Spitzer beam. The proposed observations will allow us to search for and understand the effects of companion stars, leading to a more robust statistical analysis of transition disks, in particular to confirm our earlier work which showed a possible spectral-type dependence in the occurrence of these disks.