Palomar Observatory

The Palomar Observatory is an astronomical research observatory in the Palomar Mountains of San Diego County, California, United States. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL), Yale University, and the National Astronomical Observatories of China.

The observatory operates several telescopes, including the 200-inch (5.1 m) Hale Telescope, the 48-inch (1.2 m) Samuel Oschin telescope (dedicated to the Zwicky Transient Facility, ZTF), the Palomar 60-inch (1.5 m) Telescope, and the 30-centimetre (12-inch) Gattini-IR telescope. Decommissioned instruments include the Palomar Testbed Interferometer and the first telescopes at the observatory, an 18-inch (46 cm) Schmidt camera from 1936.