Bok Telescope and Site

• Elevation: 2071 m = 6795 ft.
• Latitude: +31° 57' 46.5"
• Longitude: 111° 36' 01.6"W
• Time Zone: +7 hours

• Primary Mirror Clear Aperture: 2.29 m = 90 inches diameter
• Primary Focal Ratio: f/2.66

• f/9 Ritchey-Chretien focus
• Plate Scale: 104 microns/arcsec = 9.66 arcsec/mm (nominal)
• Usable Field of View: 45 arcminute diameter (curved focal plane)
• Central obscuration = 14%
• f/45 Cassegrain focus
• Plate Scale: 510 microns/arcsec = 1.96 arcsec/mm (nominal)
• Central obscuration = 9%

• Typical Seeing: 1.5"
• Absolute Pointing: 3" RMS over the entire sky; offset pointing: 1" over 5°
• Tracking: <3" drift per hour (open loop)
• Horizon Limits: 12.5°