obtain an independent determination of the frequency of binary occurrence, and to examine consequences of a binary system on the stability of planetary orbits. Preliminary bench testing of simple apodizing systems could tell us whether the difficult problem of high mirror surface accuracy can be overcome, for direct means of detecting planets. An effort should be made to determine which planetary molecules might possibly give rise to planetary masers, or other forms of non-thermal emission.

The prospects of increasing our confidence concerning the frequency and distribution of other planetary systems are good, if we are willing to invest the effort. As a consequence of the Workshops, several novel approaches to the problem have come to light, as have potential improvements to classical means of detecting planets.

A photograph of the Orion nebula taken with the Thaw telescope of Allegheny Observatory. The Orion nebula is a region of active star formation at present and contains not only visible stars, but a number of intense radio and infrared sources. The straight line emanating from the star below the nebulosity indicates how that star might move across the field of view if it had no planets, while the sinusoidal line indicates how the star would appear to move if it had a planetary companion which could be detected by precise astrometric observations.

COLLOQUY 4

THE RATIONALE FOR A PREFERRED FREQUENCY BAND:

THE WATER HOLE

Prepared by:

Bernard M. Oliver

Vice-President of Research

and Development

Hewlett Packard Corporation