CERRO TOLOLO INTER-AMERICAN OBSERVATORY

Cerro Tololo Inter-American Observatory (CTIO) an observatory located at an altitude of 2215 m on Cerro Tololo mountain, Chile, 55 km southeast of La Serena. Founded in 1963, it is part of the US National Optical Astronomy Observatory.  The site was identified by a team of scientists from the Chile and America in 1959, and it was selected in 1962. Construction began in 1963 and regular astronomical observations commenced in 1965. Construction of large buildings on Cerro Tololo ended with the completion of the Victor M. Blanco Telescope in 1974, but smaller facilities have been built since then. Cerro Pachón is still under development, with two large telescopes inaugurated since 2000, and one in the early stages of construction.
The main instrument is the 4-m Blanco Telescope(opened in 1974), named after the observatory's first director, the American astronomer Victor Manuel Blanco. This telescope is the southern twin of the 4-m instrument at Kitt Peak National Observatory. Other instruments include a 1.5-m reflector (opened in 1968), a 1.3-m reflector originally used for the Two-Micron All-Sky Survey, opened in 1997 but transferred to CTIO ownership in 2001; a 0.9-m reflector, opened in 1967; Yale University's 1-m reflector, installed here in 1973; and the University of Michigan's 0.6-m Curtis Schmidt, originally opened in 1950 but moved here in 1967. The 1.5‐m, 1.3‐m, 1‐m, and 0.9‐m have been operated since 2003 by the Small and Moderate Aperture Research Telescope System (SMARTS) consortium of US institutions. The Curtis Schmidt is closed. CTIO also operates the 4.1-m Southern Astrophysical Research (SOAR) Telescope on Cerro Pachón, a peak 10 km to the southeast of Cerro Tololo.