The Southern Astrophysical Research Telescope (SOAR) is a modern 4.1-meter-aperture optical and near-infrared telescope located on Cerro Pachón, Chile at 2,738 meters 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.
The telescope attains median image quality 0.7 arcsec at 0.5 μm wavelength. Multiple instruments are available on standby, mounted at Nasmyth and bent-Cassegrain foci. Switching is accomplished within a few minutes by rotating the 45° tertiary mirror. This mirror is adjusted at high speed to prevent image blur from vibrations induced by wind-shake of the telescope structure.