Engineering topics

Stein, J. W.

Publications and source records attributed to Stein, J. W..

3 records

NASA NTRS1988

Discovery and study of planetary systems using astrometry from space

The intellectual issues that must be confronted in any attempt to discover planetary systems are examined along with the implications that these issues have for the performance of instruments built for that task. The progress that potentially can be made with precise astrometric measurements is examined. Particular attention is given to the Astrometric Telescope Facility, based on the Multichannel Astrometric Photometer.

Levy, E. H.↗

NASA NTRS1986

A survey of nearby stars for the perturbatative effects of extrasolar planetary systems

A new photoelectric astrometric system, the Multichannel Astrometric Photometer (MAP), was developed, and it was used in a regular observing program designed to detect extrasolar planetary systems. The 76-cm refractor of the Allegheny Observatory was fully renovated to make it suitable as the observing instrument for the MAP. The MAP itself was designed, constructed and tested in actual operation. A data analysis system was developed and tested.

Gatewood, G. D.↗

NASA NTRS1986

Astrometric telescope of ten microarcsecond accuracy on the Space Station

The Astrometric Telescope Facility (ATF) will be operated in the NASA Space Station in the 1990s, furnishing long term, highly accurate relative astrometry of nearby stars in order to detect gravitational perturbations by companion stars with masses as small as that of Neptune. An accuracy of 10 microarcsec is required; this is 100 times better than ground observatory performance. In the Gatewood et al. (1980) astrometric technique used, the relative positions of star images in the telescope focal plane are indicated by the relative phases of the modulations of star brightnesses introduced by translating a Ronchi ruling across the focal plane at uniform speed. Space Station vibration damping, fine guiding accuracy, optical configuration, Ronchi ruling metric accuracy, and the choice of detectors, are discussed.

Levy, E. H.↗