Telescope Concept

Astronomical Consultants & Equipment	DFM Engineering
EOS Technologies	Telescope Technologies Ltd.

To meet all the science objectives that we anticipate will be set by the Science Advisory Committee, we expect the telescope will need a 2-m class aperture and a wide field of view. As described below in the performance modeling section, we are offering potential funding partners three options involving two telescope apertures: 2.5-m and 1.5 m.

To provide the wide field at these apertures, the primary mirror will probably have an f-ratio of around f/2. The telescope will most likely be designed with an overall focal ratio of approximately f/4 to f/7, to provide the wide field of view, and for one of the 1.5-m options, to keep the mechanical footprint of the telescope within the confines of the available space in the existing Winer Observatory enclosure in Sonoita, AZ.

One design approach might be to use a simple parabola for the primary, a flat for the secondary, and to place the imager with a multi-element field corrector directly in front of the primary in the shadow of the secondary (there is currently no central hole in the 1.5-m mirror blank). Refractive lenses could be used near the imager to correct the parabola's aberrations and to flatten the field. This is the approach used in the 1.8-m University of Arizona Spacewatch telescope on Kitt Peak. Another possibility is to make a Ritchey-Chretien Cassegrain with the imager in front of the primary, though the fast f-ratio will most probably require correctors, and it might be less expensive to use the folded parabolic design.