Smithsonian Astrophysical Observatory


Smithsonian Astrophysical Observatory

(SAO) A research facility of the Smithsonian Institution based in Cambridge, Massachusetts, USA. It was founded in 1890 and originally housed in a building attached to the Smithsonian Institution in Washington D.C. At first it concentrated mainly on solar research, especially into the solar constant. During the first half of the 20th century, it established several solar observing stations in the United States, South America, and Africa to conduct research on solar radiation. In 1955, under an agreement to cooperate on astrophysical research between the Smithsonian Institution and Harvard University, the SAO was transferred to Cambridge under the directorship of the astronomer Fred L. Whipple. The SAO's research activities widened to take in satellite tracking for the US space program, orbiting astronomical observatory experiments, the study of meteorites and comets, and involvement in theoretical astrophysics. In 1968, the SAO opened a major observatory on Mount Hopkins, Arizona. Here it collaborates with the University of Arizona in operating the Multiple Mirror Telescope (MMT), dedicated in 1979 and converted to a 6.5-meter single-mirror telescope in 1998. The observatory in Arizona was renamed the Fred L. Whipple Observatory in 1981. The SAO combines with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics, which was founded in 1973. The center coordinates the work of its constituent institutions under one director and carries out a broad program of research in astronomy, astrophysics, Earth and space sciences, and science education. Its current wide-ranging research activities cover atomic and molecular physics, high energy astrophysics, optical and infrared astronomy, planetary sciences, radio and geoastronomy, solar and stellar physics, and theoretical astrophysics. See also SAO Star Catalog.

Smithsonian Astrophysical Observatory

 

a scientific institution in Washington, D.C., part of the Smithsonian Institution. The observatory was founded by S. Langley in 1890 specifically to make precise measurements of solar radiation, for which it was appropriately equipped. From 1907 to 1944 it made several tens of thousands of measurements of the solar constant under the direction of C. Abbot. After World War II its program was broadened considerably to include work mainly in theoretical astrophysics and satellite geodesy; a global network of satellite observation stations was organized for the latter research. The work is conducted in close cooperation with other American observatories. The observatory publishes Annals of the Astrophysical Observatory of the Smithsonian Institution (since 1900) and Smithsonian Contributions to Astrophysics (since 1956). [23–1830–]