The WIYN Observatory is owned and operated by the WIYN Consortium, which consists of the University of Wisconsin, Indiana University, Yale University, and the National Optical Astronomy Observatories (NOAO). NOAO is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under cooperative agreement with the National Science Foundation.
The innovations that have gone into the design, testing, and construction of the new 3.5-meter WIYN telescope make it one of the most powerful telescopes in its class. New telescopes such as WIYN and the larger (8-10 meter) telescopes now under construction around the world will be valuable tools both as primary research facilities and in support of much more expensive space-based telescopes.
A comparison of the WIYN telescope, completed in 1994, with the 4-meter Mayall telescope, completed in 1973, demonstrates how innovative technology can be applied to telescope design. The WIYN telescope enclosure is a fraction of the size of the Mayall telescope dome, due both to the short focal length of the primary mirror, which results in a shorter telescope, and to the Alt-Az mount which requires less space. The moving weight of the Mayall telescope is 375 tons, while the WIYN telescope, with a primary mirror only slightly smaller in diameter, weighs only 46 tons.
Modern technology makes it possible to build very compact and very powerful telescopes. The WIYN Telescope will be more powerful than the 4-meter Mayall Telescope even though the WIYN building is much smaller.
The smaller structure reduces the cost of the facility, and modern technology continually improves performance.
The mirrors in the WIYN telescope are capable of producing much sharper images than the larger 4-meter Mayall mirror. The WIYN mount, optics supports, thermal controls and enclosure are all designed to minimize degradation of the telescope image quality by the atmosphere.
Other innovative features incorporated into the WIYN telescope design are active primary mirror supports, primary mirror thermal controls, and active ventilation of the telescope mount. The support system for the primary mirror includes 66 actuators, which push or pull on the back face of the mirror to maintain the best optical figure. The primary mirror thermal control system can maintain the temperature of the surface of the mirror to within 0.2 C of the ambient air temperature, eliminating mirror seeing, which is caused by turbulence in cool air over a warmer mirror surface. An open telescope chamber maintains the entire observatory at the nighttime air temperature. Optical tests indicate that all of these innovations in design have enabled the WIYN telescope to produce much sharper images than any of the other telescopes on Kitt Peak.
WIYN is equipped with state-of-the-art scientific instruments for astronomical spectroscopy and imaging. A multiple object spectrograph employing optical fibers allows the simultaneous observation of the spectra of 100 objects. The imaging cameras employ highly sensitive arrays of electronic detectors.
The 3.5-meter WIYN telescope is built with an Altitude-Azimuth mount. The base of the telescope rotates while the upper structure tips to reach any portion of the sky.
The 3.5-meter primary mirror collects starlight, and focuses it toward the 1.2 meter secondary mirror. The secondary mirror at the top reflects the beam downward to the tertiary mirror. In turn, the tertiary mirror reflects the beam horizontally to instruments mounted on the side of the telescope.
The WIYN Observatory (pronounced "win") is owned and operated by the WIYN Consortium, which consists of the University of Wisconsin, Indiana University, Yale University, and the National Optical Astronomy Observatories (NOAO). Most of the capital costs of the observatory, which amounted to $14 million, were provided by these universities, while NOAO, which operates the other telescopes of the Kitt Peak National Observatory, provides most of the operating services. This partnership between public and private universities and NOAO is the first of its kind. The universities benefit from access to a well-run observatory at an excellent site, and the larger astronomical community served by NOAO benefits from the addition of this large, state-of-the-art telescope to Kitt Peak's array of telescopes.
This brochure was produced by the National Optical Astronomy Observatories, Imaging and Information Services Office. NOAO operates Kitt Peak National Observatory and the National Solar Observatory in the USA, and Cerro Tololo Inter-American Observatory in Chile. NOAO is operated for the National Science Foundation by the Association of Universities for Research in Astronomy.
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