Telescopes

Kitt Peak, looking south from atop the 0.9-meter Spacewatch® telescope.
 Click image to view a 360° panorama! [340k] (Photograph by Mike Read)

Spacewatch® currently operates two telescopes on the summit of Kitt Peak. 

  1. 0.9-meter Spacewatch® telescope
  2. 1.8-meter Spacewatch® telescope

Spacewatch® 0.9-meter Telescope

0.9-m telescope 
The Spacewatch® 0.9-m telescope (left) on beautiful Kitt Peak during the winter.   (Photograph by Jim Scotti)

 

Observatory information:

Geodetic Latitude (Reference Datum WGS 84; +/- 6 meters) 31.96220°  N
Longitude (Reference Datum WGS 84; +/- 6 meters) -111.60038° E
Elevation of telescope axes (Reference Datum WGS 84; +/- 10 meters) 2.08 km
IAU Observatory Code 691

Optical configuration Old System (to 2002 April) Mosaic of CCDs (From 2002 Sept)
Optics Newtonian, f/5.34, coma corrected and field flattened Corrected prime focus, f/3
Filter Schott OG 515 * See below Schott OG-515
Primary mirror diameter 0.946 m (37.25 inches) 0.946 m (37.25 inches)
Masked mirror diameter 0.882 m (34.7 inches) Clear aperture  0.934 m (36.75 inches)
Image scale (at corrected focus) 43.8 arcsec/mm 74.0 arcsec/mm
CCD Tektronix TK2048EB1-1 (2048x2048 pixels), thinned, backside illuminated Four  E2V Technologies Model: CCD42-90-I-941, 4608 x 2048 pixels each, thinned, and backside illuminated
Pixel size 24 microns 13.5 microns
Image scale 1.05 arcsec/pixel 1.00 arcsec/pixel
Effective field of view 37' x 33' (RA x Dec) 2.9 square degrees
Exposure time 2m23s at 0° Dec;  2m38s at +/-25° Dec (drift scanning) 120 seconds (stare mode)
Limiting magnitude V = 21.5 V = 21.7

* All Spacewatch® observations have been and will continue to be made through a Schott OG 515 filter. The filter greatly simplified lens design for the broad (0.5-1.0 micron) bandpass because it allowed us to avoid an atmospheric dispersion compensator, a difficult proposition at these fast f/numbers, and allows us to use flint elements in the lens prescription. It also reduces moonlit sky background.

 

 

 

Spacewatch® 1.8-meter Telescope

1.8-m telescope 
The 1.8-m Spacewatch® telescope in its upright position.
(Photograph by Alain Maury)

Observatory information: 

Geodetic Latitude (Reference Datum WGS 84; +/- 6 meters) 31.96169° N
Longitude (Reference Datum WGS 84; +/- 6 meters) -111.59995° E
Elevation (Reference Datum WGS 84; +/- 10 meters) 2.08 km
IAU Observatory Code

291

Primary mirror: 1.8 meter diameter, f/2.7 paraboloid.
Folded prime focus, coma corrected and field flattened.
Filter: Schott OG 515; see below.
Detector: Fairchild 3041 CCD, 2048 x 2048 pixels, thinned,
          backside illuminated, and broad-band antireflection (BBAR) coated.
Pixel size: 15 microns.
Camera: Finger Lakes Instruments ProLine Model PL3041-LC, S/N PL0144010.
Image scale: 0.6 arcsec/pixel.
Field of view:  20 arcmin x 20 arcmin.
Limiting magnitude: R = 22

All Spacewatch® observations have been and will continue to be made through a Schott OG 515 filter. The filter greatly simplified lens design for the broad (0.5-1.0 micron) bandpass because it allowed us to avoid an atmospheric dispersion compensator, a difficult proposition at these fast f/numbers, and allows us to use flint elements in the lens prescription.  It also reduces moonlit sky background, being a "minus-blue" (i. e., yellow-orange) color.