A PHOTOELECTRIC ASTROMETRIC TELESCOPE USING A RONCHI RULING

• Published in: Publications of the Astronomical Society of the Pacific Vol. 102; no. 648; pp. 200 - 211
• Main Authors: BUFFINGTON, ANDREW, GELLER, MICHAEL R.
• Format: Journal Article
• Language: English
• Published: Legacy CDMS The Astronomical Society of the Pacific 01.02.1990
• Subjects: Astronomy; Atmospherics; Centroids; Coordinate systems; Declination; Field of view; Instruments and Data Analysis; Reflecting telescopes; Ronchi; Stars; Telescopes; Time series
• DOI: 10.1086/132628
• ISSN: 0004-6280

A new generation of photoelectric astrometric telescopes promises significant advances for both semiglobal and differential astrometry. Some of these new telescopes have a Ronchi ruling at the prime focal plane. The images move relative to the ruling, behind which photomultipliers or similar detectors view the modulated transmitted light. When several stars are viewed simultaneously, this technique exploits correlations in the atmospheric seeing to significantly improve differential astrometric precision. This article presents some general design and analysis criteria for this type of telescope and describes our particular reflector telescope. This has a 29-cm aperture and has met a 4-milli-arc-second differential precision per 5-minute observation. The system is designed for a program of improved annual parallax and solar-system object measurements.