  Submillimeter and near-infrared images of cool dusty debris disks and rings
suggest the existence of unseen planets. At dusty but non-imaged stars,
semi-major axes of associated planets can be estimated from the dust
temperature. For some young stars these semi-major axes are greater than an arc
second as seen from Earth. Such stars are excellent targets for sensitive
near-infrared imaging searches for warm planets. To probe the full extent of
the dust and hence of potential planetary orbits, SIRTF observations should
include measurements with the 160mu filter.
