× 0. Palomar Observatory
M. Visitor Center (Museum)
H. Hale Dome

The 60-inch (1.5-m) Telescope

The Palomar 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 the National Aeronautics and Space Administration (NASA) and the National Science Foundation. The 60-inch is currently operated robotically 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 by other telescopes, the 60-inch is a platform for testing new instrument technology.


The Palomar 60-inch telescope was added to the Observatory portfolio to address increasing demand for observational access; it was developed in the 1960s and dedicated in 1970. The 60-inch is sited at the south edge of the Observatory compound outside of the publicly-accessible area. The telescope is housed in the Oscar G. Mayer Memorial Building, and development funding was provided by the US National Science Foundation and NASA.

As originally conceived the Palomar 60-inch telescope operated conventionally with an operator and astronomers on the observing floor, and a diverse suite of instruments that could mount at the Cassegrain focus under the telescope. However, the telescope was designed with modern electro-mechanical control systems to anticipate eventual automated control. Over its history the telescope has served as both a science and engineering platform, hosting the development of novel instrumentation and operations. For example, a novel adaptive optics coronagraph was used in the 1990s to discover the first confirmed brown dwarf, GL229B. In the early 2000s the telescope was converted to robotic operation, and fitted with a dedicated CCD camera used to follow-up gamma-ray burst events. And in 2010 a first-of-its-kind automated laser guide star adaptive optics system named Robo-AO was demonstrated on the telescope.

60-inch telescope operations continue robotically to this day, now with a dedicated low-dispersion spectrometer known as the Spectral Energy Distribution Machine (or SEDM). Fitted with SEDM, the telescope operates in coordination with the Samuel Oschin Telescope as part of the Zwicky Transient Facility—a major international transient astronomy project with collaborating astronomers from across the United States and around the world.

Upcoming guided tour.