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The 1-meter (40-inch) Ritchey-Chretien Reflector at NOFS
The 1-meter (40-inch) Ritchey-Chretien Reflector at NOFS

This telescope, completed in 1934, is the largest and last Ritchey-Chretien telescope designed and built by George W. Ritchey. Originally located at the main Naval Observatory in Washington, D.C., increasingly bright urban skies led to its relocation to Flagstaff and the establishment of the Flagstaff Station in 1955. This was the telescope used in the pioneering work on the polarization of starlight by John Hall and Alfred Mikesell. The original Pyrex optics were replaced with fused quartz in 1969 and are now installed in the 1-meter Austro-Croatian Telescope at Hvar Observatory, Croatia. Today this telescope is used for a variety of imaging and photometric programs by the Flagstaff Station staff.
  • Construction
    • Optics: Corning Glass Works (blanks); George W. Ritchey and Tinsley Laboratories (optical figuring)
    • Mounting: Designed by George W. Ritchey, manufactured by Baldwin-Southwark Corporation
    • Date Completed: 1934 (new quartz optics 1969)
    • Cost (as completed): $76,000
  • Optical Design: Ritchey-Chretien
  • Effective Focal Length: 7.3 meters
  • Overall Focal Ratio: f/7.3
  • Focal Plane Scale: 28.2 arcsec/mm
  • Primary Mirror
    • Diameter: 1.0 meter (40 inches)
    • Material: Fused Silica
    • Weight: 270 kg (600 lbs)
    • Figure: Modified Concave Hyperboloid
    • Focal Ratio: f/4
  • Secondary Mirror
    • Diameter: 46 cm (18 inches)
    • Material: fused silica
    • Weight: 27 kg (60 lbs)
    • Figure: Modified Convex Hyperboloid
    • Magnification: 1.81
  • Total Weight (Optics, Tube and Mount): 8200 kg (9 tons)


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