The first 50 years at palomar: 1949-1999 - The early years of stellar evolution, cosmology, and high-energy astrophysics

An account is given of the history of two observational programs set for th e Palomar 200-inch telescope, one by Waiter Baade and the other by Edwin Hu bble near the start of the scheduled operation of the telescope 50 years ag o. The review is partly an assessment of whether, and how well, these progr ams have been carried to completion, and partly an account of the response of Palomar to new discoveries and developments not foreseen in 1950. Stella r evolution, the discovery of variations in the metallicity of stars of dif ferent populations, the chemical evolution of the Galaxy, the Cepheid P-L r elation, the redshift-distance relation of the expanding universe, and the extragalactic distance scale are discussed as they relate to the prediction s for progress on the programs set out by Baade and Hubble. Not foreseen wa s the invention and development of radio astronomy and high energy astrophy sics, leading to the discovery of radio galaxies, quasars, and the gradual realization of violent events, both in stars and in galaxies. The review is highly restricted to these subjects, covering only three areas among the t otality of the work in observational astrophysics studied during the first 50 years at Palomar.