The ARCT (formerly IRT) at RAO

The A. R. Cross Telescope

Constructed in the early 1980's, The ARCT presently resides in the largest dome on the property. The telescope is used extensively in the senior astrophysics laboratories taught at the University of Calgary.

The Optics

The primary mirror is an f/2.7, 1.8m New Generation honeycomb type from Roger Angel's workshop in Tucson. With the chopping secondary, the system is f/15 overall.

The Mount

The ARCT is supported by an Alt-Alt mount equipped with 21-bit encoders and DC servo motor, shaft-and-disk drives on both axes. The entire structure rests upon two 4.5m vertical piers in a 10m dome. This simple mounting and drive avoids the zenith 'catastrophe' of Alt-Az mounts. It has proven to be reliable and smooth in operation and easy to balance and control.

Below, are a few pictures of things related to the ARCT.

This page is perpetually under construction.