Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology. Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory, Yale University, and the National Optical Observatories of China.
The observatory operates several telescopes, including the 200-inch Hale Telescope, the 48-inch Samuel Oschin Telescope, and the Palomar 60-inch Telescope. In addition, other instruments and projects have been hosted at the observatory, such as the Palomar Testbed Interferometer and the historic 18-inch Schmidt telescope, Palomar Observatory's first telescope, dating from 1936. As of 2021, the observatory also hosts the Zwicky Transient Facility and Gattini-IR projects.