Specifications

Primary Mirror

* Effective diameter (diameter of light affecting area) : 8.2 m (27 ft.)
* Thickness: 20 cm (7.9 inches)
* Weight: 22.8 metric tons (25.1 tons)
* Material: ULE (ultra-low thermal expansion glass)
* Mean Surface error: 14 nanometer (1/5,000,000 inch)
* Focal length: 15 m (49'2")

Telescope Structure

* Mounting: altitude-azimuth (Alt-Az)
* Basic Optics: Ritchey-Chretian System
* Height: 22.2 m (72 ft.)
* Maximum width: 27.2 m (89 ft.)
* Weight: 555 metric tons (612 tons)
* Foci: Four

-Primary focus : F2.0 (with corrector lens)
-Cassegrain focus : F12.2
-Nasmyth focus (optical) : F12.6
-Nasmyth focus (infrared) : F13.6 * Maximum slewing speed: 0.5 deg/sec
* Tracking accuracy without guiding: 0.1"
* Blind pointing accuracy: less than 1.0"
* Best angular resolution achieved: 0.2"
(without adaptive optics @ 2.15 μm)

Telescope Enclosure

* Altitude: 4139 m (13,580 ft.)
* Latitude: 19d 49m 32s N (based on NAD83)
* Longitude: 155d 28m 34s W (based on NAD83)

* Cylindrical enclosure rotating with the telescope
* Height: 43 m (141 ft.)
* Diameter at base: 40 m (131 ft.)
* Weight: 2000 metric tons (2205 tons)
* Outer wall: aluminum panels

Photos of Subaru Telescope and Enclosure