Cerro Tololo Inter-American Observatory in the context of "28978 Ixion"

The Nicholas U. Mayall Telescope, also known as the Mayall 4-meter Telescope, is a four-meter (158 inches) reflector telescope located at the Kitt Peak National Observatory in Arizona and named after Nicholas U. Mayall. It saw first light on February 27, 1973, and was the second-largest telescope in the world at that time. Initial observers included David Crawford, Nicholas Mayall, and Arthur Hoag. It was dedicated on June 20, 1973 after Mayall's retirement as director. The mirror has an f/2.7 hyperboloidal shape. It is made from a two-foot (61 cm (24 in)) thick fused quartz disk that is supported in an advanced-design mirror cell. The prime focus has a field of view six times larger than that of the Hale reflector. It is host to the Dark Energy Spectroscopic Instrument. The identical Víctor M. Blanco Telescope was later built at Cerro Tololo Inter-American Observatory, in Chile.

The Two Micron All-Sky Survey (2MASS) was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and at the Cerro Tololo Inter-American Observatory in Chile, each using a 1.3-meter telescope for the Northern and Southern Hemisphere, respectively. It was conducted in the short-wavelength infrared at three distinct frequency bands (J, H, and K) near 2 micrometres, from which the photometric survey with its HgCdTe detectors derives its name.

2MASS produced an astronomical catalog with over 300 million observed objects, including minor planets of the Solar System, brown dwarfs, low-mass stars, nebulae, star clusters and galaxies. In addition, 1 million objects were cataloged in the 2MASS Extended Source Catalog (2MASX). The cataloged objects are designated with a "2MASS" and "2MASX" prefix, respectively.

The High-Z Supernova Search Team was an international cosmology collaboration which used Type Ia supernovae to chart the expansion of the universe. The team was formed in 1994 by Brian P. Schmidt, then a post-doctoral research associate at Harvard University, and Nicholas B. Suntzeff, a staff astronomer at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. The original team submitted a proposal on September 29, 1994 called A Pilot Project to Search for Distant Type Ia Supernova to the CTIO. The team on the first observing proposal comprised: Nicholas Suntzeff (PI); Brian Schmidt (Co-I); (other Co-Is) R. Chris Smith, Robert Schommer, Mark M. Phillips, Mario Hamuy, Roberto Aviles, Jose Maza, Adam Riess, Robert Kirshner, Jason Spyromilio, and Bruno Leibundgut. The project was awarded four nights of telescope time on the CTIO Víctor M. Blanco Telescope on the nights of February 25, 1995, and March 6, 24, and 29, 1995. The pilot project led to the discovery of supernova SN1995Y. In 1995, the HZT elected Brian P. Schmidt of the Mount Stromlo Observatory which is part of the Australian National University to manage the team.

The team expanded to roughly 20 astronomers located in the United States, Europe, Australia, and Chile. They used the Víctor M. Blanco telescope to discover Type Ia supernovae out to redshifts of z = 0.9. The discoveries were verified with spectra taken mostly from the telescopes of the Keck Observatory, and the European Southern Observatory.

The Víctor M. Blanco Telescope, also known as the Blanco 4m, is a 4-metre aperture telescope located at the Cerro Tololo Inter-American Observatory, Chile on the summit of Mt. Cerro Tololo. Commissioned in 1974 and completed in 1976, the telescope is identical to the Mayall 4m telescope located on Kitt Peak. In 1995 it was dedicated and named in honour of Puerto Rican astronomer Víctor Manuel Blanco.It was the largest optical telescope in the Southern hemisphere from 1976 until 1998, when the first 8-metre telescope of the ESO Very Large Telescope opened.

Currently the main research instrument used at the telescope is the Dark Energy Camera (DECam), the camera used in the Dark Energy Survey. DECam saw its first light in September 2012.

2012 VP₁₁₃ is a trans-Neptunian object (TNO) orbiting the Sun on an extremely wide elliptical orbit. It is classified as a sednoid because its orbit never comes closer than 80.5 AU (12.04 billion km; 7.48 billion mi) from the Sun, which is far enough away from the giant planets that their gravitational influence cannot affect the object's orbit noticeably. It was discovered on 5 November 2012 at Cerro Tololo Inter-American Observatory in Chile, by American astronomers Scott Sheppard and Chad Trujillo, who nicknamed the object "Biden" because of its "VP" abbreviation. The discovery was announced on 26 March 2014. The object's diameter has not been measured, but its brightness suggests it is around 450 km (280 mi) in diameter. 2012 VP₁₁₃ has a reddish color similar to many other TNOs.

2012 VP₁₁₃ has not yet been imaged by high-resolution telescopes, so it has no known moons. The Hubble Space Telescope is planned to image 2012 VP₁₁₃ in 2026, which should determine if it has significantly sized moons.

Robert A. Schommer (December 9, 1946 – December 12, 2001) was an American observational astronomer. He was a professor at Rutgers University and later a project scientist for the U.S. office of the Gemini Observatory Project at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. He was known for his wide range of research interests, from stellar populations to cosmology.

Schommer was born in Chicago, Illinois to Harvey and Bea Schommer. He received a B.A. in Physics from the University of Chicago in 1970 and a Ph.D. in Astronomy from the University of Washington in 1977, where he continued for one year as instructor. Following two years in seminary college in Chicago, he held postdoctoral positions at Caltech (as Chaim Weizmann Fellow), the Hale Observatories, the University of Chicago, and Cambridge University (as NATO Postdoctoral Fellow) before joining the Department of Physics at the State University of New Jersey. He became increasingly unhappy with the department's unwillingness to support astronomy, and in 1990 he moved to CTIO in Chile where he remained until his death in 2001.

Mark M. Phillips (born March 31, 1951) is an American astronomer who works on the observational studies of all classes of supernovae. He has worked on SN 1986G, SN 1987A, the Calán/Tololo Supernova Survey, the High-Z Supernova Search Team, and the Phillips relationship. This relationship has allowed the use of Type Ia supernovae as standard candles, leading to the precise measurements of the Hubble constant H₀ and the deceleration parameter q₀, the latter implying the existence of dark energy or a cosmological constant in the Universe.

He is the past director of Cerro Tololo Inter-American Observatory of the National Optical Astronomy Observatory and is the Associate Director and Carnegie Staff Member at Las Campanas Observatory in Chile, part of the Observatories of the Carnegie Institution for Science.

Víctor Manuel Blanco (March 10, 1918 – March 8, 2011) was a Puerto Rican astronomer who in 1959 discovered Blanco 1, a stellar cluster. Blanco was the second Director of the Cerro Tololo Inter-American Observatory in Chile, which had the largest telescope in the Southern Hemisphere at the time. In 1995, the 4-meter telescope was dedicated in his honor and named the Víctor M. Blanco Telescope; it is also known as the "Blanco 4m."

The Dark Energy Survey (DES) is an astronomical survey designed to constrain the properties of dark energy. It uses images taken in the near-ultraviolet, visible, and near-infrared to measure the expansion of the universe using Type Ia supernovae, baryon acoustic oscillations, the number of galaxy clusters, and weak gravitational lensing. The collaboration is composed of research institutions and universities from the United States, Australia, Brazil, the United Kingdom, Germany, Spain, and Switzerland. The collaboration is divided into several scientific working groups. The director of DES is Josh Frieman.

The DES began by developing and building Dark Energy Camera (DECam), an instrument designed specifically for the survey. This camera has a wide field of view and high sensitivity, particularly in the red part of the visible spectrum and in the near infrared. Observations were performed with DECam mounted on the 4-meter Víctor M. Blanco Telescope, located at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. Observing sessions ran from 2013 to 2019; as of 2021 the DES collaboration has published results from the first three years of the survey.

The Southern Astrophysical Research (SOAR) telescope is a modern 4.1-meter-aperture (13 ft) optical and near-infrared telescope located on Cerro Pachón, Chile, at 2,738 metres (8,983 ft) elevation. It was commissioned in 2003, and is operated by a consortium including the countries of Brazil and Chile, Michigan State University, the Cerro Tololo Inter-American Observatory (CTIO) (part of the National Optical Astronomy Observatory, NOAO), and the University of North Carolina at Chapel Hill. Partners have guaranteed shares varying from 10 to 30 percent of the observing time.

The telescope uses active optics on its primary and secondary mirrors to attain median image quality 0.7 arcsec at a wavelength of 500 nm. Multiple instruments are available on standby, mounted at unusually high weight-capacity Nasmyth foci and two lower capacity bent-Cassegrain foci. Switching is accomplished within a few minutes by rotating the 45° tertiary mirror. The pointing of this mirror is adjusted at high speed to prevent image blur from vibrations induced by wind-shake of the telescope structure.

PROMPT, an acronym for Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes, is being built by the University of North Carolina at Chapel Hill at Cerro Tololo Inter-American Observatory (CTIO) in Chile. PROMPT's primary objective is rapid and simultaneous multiwavelength observations of gamma-ray burst afterglows, some when they are only tens of seconds old. In addition to measuring redshifts by dropout, and early-time SFDs and extinction curves of sufficiently bright afterglows in unprecedented detail, PROMPT will facilitate quick response observations at larger observatories such as the UNC-led 4.1-m SOAR Telescope. PROMPT will also serve as a platform for undergraduate and high school education throughout the State of North Carolina.

PROMPT consists of six 0.41-m Ritchey-Chrétien telescopes by RC Optical Systems on rapidly slewing (9°/sec) Paramount ME mounts by Software Bisque, each under a clamshell dome by Astro Haven. Five of these telescopes use rapid-readout (<2 sec) Alta U47+ cameras by Apogee, which make use of E2V CCDs. The sixth is being outfitted with an LN2-cooled Micro-Cam by Rockwell Scientific for NIR imaging. Each mirror and camera coating combination has been optimized for a different wavelength range, including a u-band optimized telescope. Although other filters are available, PROMPT automatically observes GRB localizations in ugriz simultaneously. The R-band telescope will additionally measure polarizations. The polarimeter was designed and built at UNC's Goodman Laboratory for Astronomical Instrumentation.

2021 PH₂₇ is a kilometer-sized Atira-type near-Earth asteroid orbiting very close to the Sun. It was discovered by Scott Sheppard using the Dark Energy Camera (DECam) at Cerro Tololo Inter-American Observatory on 13 August 2021. 2021 PH₂₇ has the smallest semi-major axis and shortest orbital period among all known asteroids as of 2026, with a velocity at perihelion of 106 km/s (240,000 mph). It also has the largest relativistic perihelion shift of any known object orbiting the Sun, 1.6 times that of Mercury. 2021 PH₂₇ shares an identical orbit and color as 2025 GN1, which has led astronomers to believe that the two asteroids split apart from a parent body over 10,500 years ago.

(87269) 2000 OO₆₇ (provisional designation 2000 OO₆₇) is a trans-Neptunian object, approximately 64 kilometers (40 miles) in diameter, on a highly eccentric orbit in the outermost region of the Solar System. It was discovered by astronomers at the Chilean Cerro Tololo Inter-American Observatory on 29 July 2000.