2.1-m Otto Struve Telescope

The Struve Telescope has a 2.1-meter (82-inch) primary mirror, with three available foci (primary, Cassegrain and coudé, of which only the Cassegrain is currently used).  The telescope was the first one at McDonald Observatory, constructed 1933-39, at which time it was the second largest in the world.  The Telescope Control System (TCS) was recently upgraded to modern standards.

Telescope Safety and Operating Information

Telescope Parameters

Optical
Primary mirror
Diameter 2.08 m (82")
Focal length 8.13 m (26.7')
F-ratio 3.9
Field angle 63.5 arcmin
Plate scale 25.4 arcsec/mm
Cassegrain focus
Focal length 28.53 m (96.6')
F-ratio 13.7
Field angle 20 arcmin
Plate scale 7.23 arcsec/mm
Coudé focus - decommissioned
Focal length 47.70 m (156.5')
F-ratio 22.9
Plate scale 4.3 arcsec/mm
Mechanical
Primary mirror
Weight 1900 kg (4200 lbs)
Thickness 29.8 cm (11.75")
Material Borosilicate glass (Pyrex™)
Telescope
Diameter 2.64 m (8'8")
Length 8.2 m (27')
Weight 41 t (45 tons)
Bearings
Polar axis SKF ball radial thrust bearings
Dec axis Tapered roller bearings
Dome
Diameter 19 m (62')
Weight 104 t (115 tons)

 

Historical
Construction
Started 1933
Completed 1939
Contractor
Design Otto Struve
Telescope Warner and Swasey Co.
Dome Patterson Leitch Co.
Optics C. Lundin

 

Instruments

Cassegrain focus: f/13.7

Fast read-out optical camera optimized for ~4,000 - 8,000 Å (verify)

Deep depletion CCD camera optimized for 7,000 - 11,000 Å

Fast, low-resolution, 8-band slit-less CMOS-based spectrograph

Telescope Control System

  • Remote observing capability.
  • Automation to target.
  • Autoguiding.
  • Sidereal tracking and ephemeris tracking using JPL Horizons data. HA track rate 1 to 18 arcsec/sec west, declination +-150 arcsec/sec.
  • Dome automation during tracking.
  • Computer control of dome slit, mirror cover, and baffle tube. Wide-field surveillance cameras on dome and tube.