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R.E. Stencel (Univ. Denver Observatories), E.T. Meyer (The Meyer Foundation)
An unusual dual-aperture 28.5-inch, f/21 Ritchey-Chretien telescope has been installed in the recently upgraded University of Denver extreme high altitude observatory facility, atop 14,268 ft. Mount Evans in Colorado -- see 1994 BAAS 26:895 & 26:1321; 1998 BAAS 29:1272 & 30:1293; www.du.edu/~rstencel/MtEvans. Designed to optimize high spatial resolution imaging, the Meyer Binocular Telescope incorporates active thermal management of the telescope structure. The secondary mirror support elements are fabricated from INVAR and permit active tip-tilt and focusing capability. The optics were fabricated from Zerodur by Contraves USA, and each system has a measured total wavefront error less than 0.050 at 633nm. All optical surfaces are coated with a multi-layer dielectric enhanced silver, providing high reflectance from below 350nm to beyond 26 microns. During 1998, the first operational phases revealed that uncorrected image performance met image quality expectations. The dual Ritchey-Chretien optical systems were fabricated by Contraves USA. They incorporate a 0.7m F3 primary mirror and a 12cm, 7 power secondary mirror for a combined focal length of 14.92 meters. The Strehl ratio for both systems is approximately 94 noteworthy that these two telescopes are nearly identical in focal length and aperture thus simplifying the exchange of instrumentation between, and comparison of data obtained at, the two telescopes. All four mirrors are coated with a multilayer enhanced (protected) silver FSS 99 from Denton Vacuum. The low emissivity of this coating in the thermal infrared complement the low precipitable H2O levels measured at the Mount Evans site. The telescope control system has been designed to allow initial operation from an insulated control room. Long-term plans call for attended and remote operation from the University of Denver campus via direct microwave radio link, over a 35 mile direct line of sight. The University of Denver astronomy program is grateful to the Meyer Foundation and the estate of William Herschel Womble for support to Denver University for these endeavors. A CDROM is available including 1998 observing results, plus ancillary and site survey data. Persons with serious student projects and/or optical/infrared focal plane instruments to test at our site are encouraged to contact us directly (rstencel@du.edu).
If the author provided an email address or URL for general inquiries, it is a
s follows:
www.du.edu/~rstencel/MtEvans