Basic Information About the Temporary Replacement CCD for the Kuiper Telescope

Two observing modes are offered to observers:

(1) The 1K CCD mounted directly to the facility filter wheel. This allows for the same filter selection and options that were available for the old 2KBigCCD system.

(2) A focal reducer can be mounted on the telescope instead of the facility filter wheel. Please be aware that use of the focal reducer will compromise sensitivity in the blue and that its 6-position manual 2"x2" filter wheel must be used. Filters in the wheel are difficult to change after initial setup at the start of your observing run since the instrument must be dismounted from the telescope by operations personnel.

Focal Reducer: Is a reflecting off-axis collimator mirror, folding flat mirror, exit pupil at the (2" x 2") filters followed by a 35mm camera lens that forms the image onto the CCD. The lens compromises B, and whacks U. A camera lens of 200mm gives a field of 556 arcsec/side (0.54 arcsec/px), while a 150mm camera lens gives a field of 740 arcsec/side (0.72 arcsec/px). Filters are difficult to install because it requires the CCD be dismounted for access. Filters are rotated by hand and located by looking into 4 holes intended for Hall effect sensors to look at the magnet configuration. The R-band throughput is generally what you expect for two reflections and a standard coated camera lens (~75% - but there is a 5-9X signal density increase per pixel).

Steward Observatory thanks Steve Larson of LPL for loaning this equipment to the Kuiper Telescope during the 2001 fall trimester.