Celebrating 75 Years of Discovery

Palomar Observatory Telescopes

Palomar Observatory is home to three active research telescopes that are involved in a wide variety of astronomical research programs. The studies conducted here range from the hunt for near-Earth asteroids to probing distant galaxies and quasars.

Currently Operational Telescopes

From top to bottom, the 200-inch (5.1-meter) Hale Telescope, the 48-inch (1.2-meter) Samuel Oschin Telescope, and the 60-inch (1.5-meter) telescope. (Palomar/Caltech)

The 200-inch (5.1-meter) Hale Telescope

The celebrated 200-inch Hale Telescope, named for astronomer and visionary George Ellery Hale, is considered one of the most consequential scientific instruments of the past 100 years. The “Big Eye” was the world's most prominent and productive telescope between 1948 and 1993, until Keck 1’s first light. The monolithic mirror’s vast collecting area—about 31,000 square inches or 20 square meters—in combination with state-of-the-art instrumentation maintain the Hale's scientific contributions at the forefront of modern astronomy. [more…]

The 48-inch (1.2-meter) Samuel Oschin Telescope

The Samuel Oschin Telescope, a wide-field Schmidt telescope designed for survey work, has a 48-inch (1.2-meter) aperture with a glass corrector plate and a 72-inch (1.8-meter) mirror. Since 1949, equipped first with photographic plates and then with CCDs, the 48-inch surveys and maps the entire northern sky. The telescope was renamed in 1986 after entrepreneur Samuel Oschin for his generous donation to the Observatory. It currently operates as a robotic instrument, scanning the skies nightly and returning a wealth of astronomical data. [more…]

The 60-inch (1.5-meter) Telescope

The 60-inch telescope, located in the Oscar G. Mayer Memorial Building, was built to take some of the demand off of the 200-inch Hale Telescope. It was dedicated in 1970 thanks to a gift of the Mayer family and grants by NASA and the National Science Foundation. The 60-inch is currently operated remotely by astronomers from Caltech and partner institutions. In addition to being used for follow-up observations of potentially interesting astronomical phenomena first detected by sky surveys or other telescopes, the 60-inch is a platform for testing new instrument technology. [more…]

Decommissioned Telescopes

The Palomar Testbed Interferometer (PTI)

Until 2008, the Palomar Testbed Interferometer (PTI) was operated by the Jet Propulsion Laboratory. It worked by collecting light with three small telescopes separated by up to 360 feet (110 meters). The large distance between the telescopes allowed for high angular resolution measurements to be made. The light was directed through pipes to the central beam combining building where it was analyzed. PTI had the remarkable capability of resolving stars and their environments. During its lifetime, it was the highest angular resolution telescope at Palomar Observatory. [more…]

The 18-inch (0.46-meter) Schmidt Telescope

The 18-inch Schmidt telescope was the first instrument at Palomar Observatory and it was Palomar's only operational telescope between 1936 and 1949. Beginning in the late 1940s, this instrument was used in conjunction with the 48-inch Schmidt (later to become the Samuel Oschin Telescope) to provide targets for the 200-inch Hale Telescope. Between the 1970s and 90s, the 18-inch proved to be a workhorse in the systematic search for minor bodies in the Solar System. In its long and productive life, this telescope yielded many discoveries, including a large number of asteroids and nearly 50 comets. The 18-inch Schmidt was decommissioned in the mid-1990s and is currently on display at the Greenway Visitor Center. [more…]

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Last updated: 26 March 2019 ACM