Acquisition of a Laser Interferometer for the Allegheny Observatory Plate Measuring Machine

利用私人和匹兹堡大学的资金，阿勒格尼天文台购买了一台Perkin Elmer 10 × 10英寸PDS测量机和计算机设备。然而，正如通常供应的那样，Perkin-Elmer机器提供的精度只比十年前的机器稍微好一点。只有安装激光干涉仪才能充分发挥机器的潜力。国家科学基金会将支持该干涉仪的购置。这台机器计划了一个新项目，将提供：1)对构成亮度函数的代表性恒星样本进行直接三角测量，测量范围在太阳100秒差距以内；2)对附近大多数双星进行精确的质量测量；3)对该体积内已知的大多数恒星进行精确的距离测量；4)系统地寻找质量小到土星的看不见的伴星。天文台收集的11万块板，以及由解冻30英寸折射镜和基勒-里奇-克雷蒂安反射镜收集的板，将与升级后的PDS机器一起使用，以实现科学目标。

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.