Mid-Scale Observatories — Cerro Tololo Inter-American Observatory


Cerro Tololo Inter-American Observatory (CTIO), a program of the NOIRLab, is a complex of astronomical telescopes and instruments located approximately 500 km (310 miles) north of Santiago, and 80 km (50 miles) to the east of La Serena, Chile, at an altitude of 2200 meters (7200 feet).

CTIO operates the 4.0-meter Blanco telescope on Cerro Tololo which features the Dark Energy Camera (DECam), a high-performance, wide-field CCD imager built to carry out the Dark Energy Survey (DES) (a US Department of Energy Office of Science-led project). It also operates the 4.1-meter Southern Astrophysical Research (SOAR) Telescope on the adjacent Cerro Pachón (a partnership between Ministério da Ciência, Tecnologia, Inovações e Comunicações Brazil, NOIRLab, the University of North Carolina at Chapel Hill and Michigan State University). The Cerro Tololo 1.5-meter and 0.9-meter telescopes are being operated by the SMARTS Consortium with support from CTIO. Cerro Tololo also hosts 11 tenant observatories and research projects, operating more than 20 telescopes, providing a platform for access to the southern hemisphere for US and worldwide scientific research.


List of telescopes currently available and supported by NOIRLab staff.


Current instruments available at Cerro Pachón and Cerro Tololo.


Filters available for MSO-CTIO facilities. For a full list of filters at all NOIRLab sites, check our Filter Database.


List of other telescopes and facilities housed at MSO-CTIO, with links to further information or to their host institutions.