MCDONALD OBSERVATORY

observatory founded in 1939 by the University of Texas, on the legacy of the Texas financier William J. McDonald, on Mount Locke near Fort Davis, Texas. The observatory includes the original 82-in. (208-cm) reflector, for many years the world's second largest telescope; a 107-in. (272-cm) reflector, dedicated in 1968; two smaller reflectors; and a dish antenna, 16 ft (5 m) in diameter, used for millimetre wave research. The associated University of Texas Radio Astronomy Observatory, for radio source positional work and studies of Jupiter, is situated 37 mi (60 km) to the south. The observatory, which until 1963 was operated under a joint agreement with the University of Chicago, has been directed successively by Otto Struve, Gerard Kuiper, Bengt Stromgren, W.W. Morgan, and Harlan J. Smith. Discoveries credited to the observatory include those of Nereid, a satellite of Neptune, and Miranda, a satellite of Uranus. Principal research has emphasized stellar composition and evolution and the properties of external galaxies. Other research specialties include high-speed photometry and lunar laser and satellite ranging.