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.

Science goals

High resolution spectroscopy.

Coudé Auxiliary Telescope

Name: Coudé Auxiliary Telescope
Site: La Silla
Altitude: 2375 m
Enclosure: Classical dome connected to ESO 3.6 m dome
Type: Spectrographic telescope
Optical design: Coudé (feeds the spectrograph of the 3.6-metre)
Diameter. Primary M1: 1.47 m
Material. Primary M1: Borosilicate
Diameter. Secondary M2: 0.22 m
Material. Secondary M2: N/A (four interchangeable M2 secondaries mounted on a turret)
Diameter. Tertiary M3: 0.254 m
Mount: Equatorial siderostat mount
First Light date: 5 May 1981
Decommissioning date: Connected to ESO's 3.60 m telescope via optical fiber in 1998
Images taken with CAT: Link
Images of CAT: Link
Videos of CAT: Link
Press Releases with CAT: Link