Cerro Tololo Observatory

The Cerro Tololo Inter-American Observatory (CTIO, IAU code 807) is a complex of astronomical telescopes and instruments located at 30.169 S, 70.804 W, approximately 80 km to the East of La Serena, Chile at an altitude of 2200 metres. The complex is part of the National Optical Astronomy Observatory (NOAO) along with Kitt Peak National Observatory (KPNO) in Tucson, Arizona. Dr. Nicholas U. Mayall was intimately involved in its creation.

The principal telescopes are the 4-m Victor M. Blanco Telescope, named after Puerto Rican astronomer Victor Manuel Blanco, and the 4.1-m Southern Astrophysical Research (SOAR) telescope, dedicated in April of 2004. The latter telescope is actually situated on the neighboring Cerro Pachon, but is managed by CTIO. Other telescopes on Cerro Tololo include the 1.5-m, 1.3-m, 0.9-m, and the Yale 1.0-m telescopes operated by the SMARTS consortium of universities and research institutes. CTIO also host many tenant observatories and research projects, such as PROMPT, ALO, WHAM, and soon LCOGTN, providing a platform for access to the southern hemisphere for U.S. and world-wide scientific research.

The NOAO is operated by the Association of Universities for Research in Astronomy (AURA), which also operates the Space Telescope Science Institute and the Gemini Observatory. One of the two 8-m telescopes comprising the Gemini Observatory is co-located with CTIO on AURA property in Chile.

The National Science Foundation (NSF) is the funding agency for NOAO.