|
The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation, he orchestrated the planning, design, and construction of the observatory, but did not live to see its commissioning. The ''Hale'' was groundbreaking for its time, with double the diameter of the next largest telescope and pioneering the use of many technologies such as vapor deposited aluminum and low thermal expansion glass. It is still in active use. It was the largest optical telescope in the world from its completion in 1948 until the BTA-6 was built in 1976, and the second largest until the construction of the Keck 1 in 1993. == History == Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the telescope in 1908 and the telescope in 1917. These telescopes were very successful, leading to the rapid advance in understanding of the scale of the Universe through the 1920s, and demonstrating to visionaries like Hale the need for even larger collectors. The chief optical designer for Hale's previous 100-inch telescope was George Willis Ritchey, who intended the new telescope to be of Ritchey–Chrétien design. Compared to the usual parabolic primary, this design would have provided sharper images over a larger usable field of view. However, Ritchey and Hale had a falling out. With the project already late and over budget, Hale refused to adopt the new design, with its complex curvatures, and Ritchey left the project. The Mount Palomar Hale telescope turned out to be the last world-leading telescope to have a parabolic primary mirror.〔, p. 317.〕 In 1928 Hale secured a grant of $6 million from the Rockefeller Foundation for "the construction of an observatory, including a 200-inch reflecting telescope" to be administered by the California Institute of Technology (Caltech), of which Hale was a founding member. In the early 1930s, Hale selected a site at on Palomar Mountain in San Diego County, California, US, as the best site, and less likely to be affected by the growing light pollution problem in urban centers like Los Angeles. The Corning Glass Works was assigned the task of making a primary mirror. Construction of the observatory facilities and dome started in 1936, but because of interruptions caused by World War II, the telescope was not completed until 1948 when it was dedicated. Due to slight distortions of images, corrections were made to the telescope throughout 1949. It became available for research in 1950.〔 The ''Hale'' saw first light on January 26, 1949 under the direction of American astronomer Edwin Powell Hubble, targeting NGC 2261, an object also known as Hubble's Variable Nebula.〔(January 26: 60th Anniversary of Hale Telescope "First Light" ). 365daysofastronomy.org (2009-01-26). Retrieved on 2011-07-01.〕〔(Caltech Astronomy : Palomar Observatory Astronomical Images – Hubble's Variable Nebula NGC 2261 ). Astro.caltech.edu (1949-01-26). Retrieved on 2011-07-01.〕 The photographs made then were published in the astronomical literature and in the May 7, 1949 issue of ''Collier's Magazine''. The telescope continues to be used every clear night for scientific research by astronomers from Caltech and their operating partners, Cornell University, the University of California, and the Jet Propulsion Laboratory. It is equipped with modern optical and infrared array imagers, spectrographs, and an adaptive optics〔 system. It has also used Lucky cam, which, in combination with adaptive optics pushed the mirror close to its theoretical resolution for certain types of viewing. One of the Corning Labs' glass test blanks for the ''Hale'' was used for the C. Donald Shane telescope's primary mirror.〔(120-inch Shane Reflector ). Ucolick.org. Retrieved on 2011-07-01.〕 The collecting area of the ''Hale'' is about 31,000 square inches (20 square meters).〔(Palomar FAQ: How far can the Hale telescope see? )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hale Telescope」の詳細全文を読む スポンサード リンク
|