The Cerro Tololo Inter-American Observatory (CTIO) is an astronomicalobservatory located on Cerro Tololo in the Coquimbo Region of northern Chile, with additional facilities located on Cerro Pachón about 10 kilometres (6.2 mi) to the southeast. It is within the Coquimbo Region and approximately 80 kilometres (50 mi) east of La Serena, where support facilities are located. The site was identified by a team of scientists from Chile and the United States 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 Víctor 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 principal telescopes at CTIO are the 4 m Víctor M. Blanco Telescope, named after Puerto Rican astronomer Victor Manuel Blanco, and the 4.1 m Southern Astrophysical Research (SOAR) telescope, which is situated on Cerro Pachón. Other telescopes on Cerro Tololo include the 1.5 m, 1.3 m, 1.0 m, and 0.9 m telescopes operated by the SMARTS consortium. CTIO also hosts other research projects, such as PROMPT, WHAM, and LCOGTN, providing a platform for access to the southern hemisphere for U.S. and world-wide scientific research.
The Small and Medium Research Telescope System (SMARTS) is a consortium formed in 2001 after NOAO announced it would no longer support anything smaller than two meters at CTIO. The member institutions of SMARTS now fund and manage observing time on four telescopes that fit that definition. Access has also been purchased by individual scientists. SMARTS contracts with NOAO to maintain the telescopes it controls at CTIO, and NOAO retains the right to 25% of the observing time, and Chilean scientists retain 10%. SMARTS began managing telescopes in 2003.
CTIOPI is the Cerro Tololo Interamerican Observatory Parallax Investigation. It began in 1999 and uses two telescopes at Cerro Tololo, the SMARTS 1.5 m reflector and the SMARTS 0.9 m reflector. The purpose of CTIOPI is to discover nearby red, white, and brown dwarfs that lurk unidentified in the solar neighborhood. The goal is to discover 300 new southern star systems within 25 parsecs by determining trigonometric parallaxes accurate to 3 milliarcseconds.
The Southern H-Alpha Sky Survey Atlas (SHASSA) operated at CTIO from 1997 to 2006 in its own small dome, which was dubbed El Enano by the local staff. It was removed at the end of the project and donated to a school in La Serena.
On the morning of Saturday, December 7, 2013, Luis González, a research assistant at the University of Chile, discovered what would later be confirmed as a supernova by José Maza, an astronomer at University of Chile and a researcher for CATA ( Centro de Astrofísica y Tecnologías Afines or “Centre for Astrophysics and Related Technologies”). The supernova is the first discovery to be made by the CATA 500, a robotic telescope designed and operated by a Chilean team located in Santiago, approximately 500 kilometres to the south. It is part of the GLORIA project, which provides open access to astronomers from around the world to a network of remotely operated robotic telescopes. The new supernova lies in the galaxy ESO 365-G16, located 370 million light years from Earth, and has a mass eight times that of our Sun.
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