The Sierra Nevada Observatory (Spanish: Observatorio de Sierra Nevada; OSN; code: J86) is located at Loma de Dilar (2896 m altitude) in the Sierra Nevada mountain range, in the province of Granada, Spain; established in 1981. It is operated and maintained by the Instituto de AstrofĂsica de AndalucĂa (Institute of Astrophysics of Andalusia - IAA) and contains two Nasmyth telescopes with apertures of 1.5 and 0.9 metres.
The Southern Astrophysical Research (SOAR) telescope is a modern 4.1-meter-aperture (13Â ft) optical and near-infrared telescope located on Cerro PachĂłn, Chile, at 2,738 metres (8,983Â 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.