The 1.0-m Ritchey-Chretien Reflector

1.0-m RC Telescope

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 Hall and Mikesell. The Pyrex optics were replaced with fused quartz in 1969. Today this telescope is used for a variety of imaging and photometric programs by the Flagstaff Station staff.

Telescope Data

  • Construction
    • Optics: Corning Glass Works (blanks); Tinsley Laboratories (optical figuring)
    • Mounting: George W. Ritchey
    • Date Completed: 1934 (new quartz optics 1969)
    • Cost:
  • 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)


  • Pi2k - Tektronix 2048x2048 CCD Camera
  • Tektronix 1024x1024 CCD Camera
  • Single-Channel Photoelectric Photometer
  • NIFOE - Naval Observatory / Indiana University Faint Object Eschelle Spectrograph

Current Research Programs

  • Photometry of stars on the 1.55-m parallax program
  • Photometry of Cepheid variables
  • Structure of spiral galaxies
  • Optical counterparts to Gamma-Ray Bursts - quiescent and rapid follow-up
  • Measurement of long-term trends in sky brightness
  • SDSS photometric system definition