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

Night Reports (Read-only.  To file, use TCS)

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.