Palomar Observatory

(redirected from Palomar Mountain Observatory)
Also found in: Acronyms.

Palomar Observatory

(pal -ŏ-mar) A world-famous observatory sited on Mount Palomar, about 65 kilometers northeast of San Diego, California, USA, at an altitude of 1713 meters. It is owned and operated by the Pasadena-based California Institute of Technology (Caltech). The site of the observatory was chosen by George Ellery Hale as suitable for a giant 200-inch (5.08-meter) telescope, following the success of the 100-inch Hooker telescope at Mount Wilson Observatory. The 200-inch reflector, now known as the Hale telescope, saw first light in Dec. 1947. Regular observing began in 1949. It was the world's largest telescope until the Soviet 6-meter instrument was built during the 1970s at Zelenchukskaya Observatory in the Caucasus. Now equipped with sophisticated electronic and computer systems, the Hale remains one of the world's most powerful telescopes.

The 200-inch mirror, ready for use in late 1947, almost 10 years after Hale's death, had been cast in 1934 after considerable design problems. It is of low-expansion Pyrex glass, with a reflecting surface of aluminum; it weighs 13.15 tonnes. The chosen focal ratio of f/3.3 meant that a much shorter tube could be used than with previous telescopes, which traditionally had an f/5 ratio. There is a Cassegrain focus, focal ratio f/16, and coudé foci of f/30.

In addition to the 200-inch, the Palomar Observatory has a 48-inch (1.24-meter) Schmidt telescope – the Oschin Telescope. This has a 1.83-meter primary mirror, focal ratio f/2.5, and a field of semiangle of 3°. It was used in the production of the Palomar Sky Survey. A new achromatic correcting plate was made in 1984. In addition there are an 18-inch (45.72-centimeter) Schmidt and a 60-inch (1.52-meter) reflector. Both the Oschin Telescope and the 60-inch have been modernized with the installation of CCD cameras.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Palomar Observatory


(Mount Palomar Observatory), a scientific institution of the California Institute of Technology (USA). Located 220 km south of Pasadena, Calif., at an elevation of 1,700 m., it houses the world’s largest reflector, with a mirror measuring 508 cm in diameter (installed in 1949), and a 122-cm Schmidt telescope, the second largest in the world (installed in 1948). It also has a 51-cm reflector and Schmidt cameras with 46-cm and 20-cm apertures. Its principal areas of research are extremely remote objects of the universe (galaxies, quasars and other quasistellar objects) and spectroscopic studies of stars and nebulae. In 1949 it was administratively merged with Mount Wilson Observatory. Palomar Observatory compiles and publishes a photographic atlas of a significant portion of the sky as well as atlases of galaxies.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.