Coudé Auxiliary Telescope (decommissioned)
The ESO Coudé Auxiliary Telescope (CAT) was housed in a smaller dome, adjacent to the 3.6-metre telescope at ESO's La Silla Observatory, and fed the 3.6-metre's Coudé Echelle Spectrometer through a light tunnel. The CAT was fully computer controlled and was used for many different types of astronomical observations, including measuring the ages of ancient stars.
High resolution spectroscopy.
Coudé Auxiliary Telescope