A 3 m Class Telescope with Active and Adaptive Optics. With special regard to the Iranian National Observatory

Abstract: A 3m ground-based optical telescope, with active and adaptive optics, is a powerful and versatile research tool. This type of telescopes is affordable and manageable also for communities with limited previous telescope experience. While there are many scientific and technical reports regarding modern 3m class telescopes, there is no document giving a comprehensive description. This paper is an attempt to fill this gap. For a 3 m class telescope, some properties of active and adaptive optics are discussed and the corresponding benefits described. The statements have been validated and illustrated via some results obtained from laboratory simulations and on-sky observations at Lund Observatory. A brief account is given of some science targets adequate and attractive with this class of telescope. Requirements are presented for a site adequate for a telescope of the type discussed. Some crucial site properties are commented. Concerning telescope design, special attention is dedicated to important properties of optomechanics, optics and mechanics, while control functions are briefly described. Emphasis is given to concepts of foci and their properties, optical elements, their design, production and characteristics, optical telescope parameters, mechanical systems as mirror cells, centre sections, tubes and top rings and their combinations mutually as well as with optical elements. A brief account is given of telescope enclosures, emphasizing their critical role for high-quality observational results. The topics and properties discussed are, to some extent, condensed in a closing chapter. Here a brief proposal is given for a high-quality yet affordable telescope of 3 m class.