The 2.2-meter telescope at the Calar Alto Observatory, inaugurated in 1979, is a highly precise optical instrument located at 2,168 meters in the Sierra de los Filabres, Almería. Its Ritchey-Chrétien design allows observations with an f/8 focal ratio, which can be reduced to f/4.4 using the CAFOS (Calar Alto Faint Object Spectrograph), specialized in direct imaging, spectroscopy, polarimetry, and near-infrared observations.

This telescope is essential for astrophysical research, contributing to studies of star formation, active galaxies, and transient events such as gamma-ray bursts. It also hosts other advanced instruments like CAFE (Calar Alto Fiber-fed Échelle spectrograph), a high-resolution spectrograph capable of measuring radial velocities with exceptional precision.

With a 2.2-meter aperture and a focal length of 17,037 mm, it offers a spatial resolution of 12.1″/mm at the Cassegrain focus. Its versatility makes it a valuable tool for professional astronomical observation, enabling the exploration of a wide range of cosmic phenomena.