Using private and University of Pittsburgh funds, the Allegheny Observatory has purchased a Perkin Elmer 10-by-10 inch PDS measuring machine and computer facility. However, as normally supplied, the Perkin-Elmer machine provides precisions only slightly better than machines of a decade ago. The full potential of the machine is only realized with the installation of a laser interferometer. The National Science Foundation will support the acquisition of this interferometer. A new program is planned with this machine that will provide: 1) direct trigonometric measurements of a representative sample of the stars making up the luminosity function within 100 parsecs of the Sun, 2) accurate masses for most of the nearby binary stars, 3) accurate distances to most of the stars known to be within that volume, and 4) a systematic search for unseen companions with masses down to that of Saturn. The Observatory's 110,000 plate collection, as well as plates being obtained with the Thaw 30-inch refractor and a Keeler Ritchey-Chretien reflector, will be used with the upgraded PDS machine to attain the scientific goals.
