The Palomar Observatory is located near San Diego, California. The observatory building project was launched in 1928 by the California Institute of Technology (Caltech) with funding from the Rockefeller Foundation. The site of Mount Palomar was chosen in 1934. World War II postponed its commissioning until 1949. Successor of the Observatory of Mount Wilson, it was equipped with the largest telescope and kept status until 1976. This telescope 5.08 meters was named "Hale" in honor of astronomer George Ellery HALE, famous astronomer responsible for the creation of the Mount Wilson Observatory and instigator of Mount Palomar Observatory. The two institutions were linked for a long time. They were jointly managed before being separated in 1980.
In addition to the Hale telescope, smaller ones were installed, including a 122 cm (48 inch) in 1948, later baptized Schmidt in honor of Maarten SCHMIDT (1929-), and a 152.4 cm in diameter (60 inches) in 1970. The Palomar Observatory has many other instruments that have been improved as techniques evolve. It remains one of the most important places for the study of the stars.
In addition to the many discoveries allowed by the Palomar Observatory, a photography campaign began in 1949. They were made from the Schmidt telescope and published in 1958 in National Geographic. This study is called NGS-POSS (National Geographic Society - Palomar Observatory Sky Survey), later the images were used in many astronomical catalogs. A large number of discoveries were made by working from the photographs obtained during this study.