The golden oldie of ESO

The 3.6-metre telescope, located at the La Silla Observatory, is truly ESO’s golden oldie. Having achieved first light in 1976, it is one of the oldest ESO telescopes still in use, and it is continuously upgraded to match the latest technology. This Picture of the Week shows a fish-eye view of the dome where the telescope sits, as stars rotate above it around the Southern celestial pole. 

ESO’s 3.6-metre telescope is located in the larger dome to the left of the above photograph and, today, astronomers use it to search for exoplanets. Since 2008, the telescope has been home to the High Accuracy Radial Velocity Planet Searcher instrument (HARPS) which was joined by the Near InfraRed Planet Searcher (NIRPS) in June this year. As the world’s foremost exoplanet specialists, HARPS, NIRPS and the 3.6-metre make a splendid team for making exciting new discoveries about distant worlds.

The smaller dome used to house the Coudé Auxiliary Telescope (CAT). One of the goals of CAT, which was decommissioned in 1998, was to determine ages of stars in the Milky Way, one of the trickier questions in stellar astronomy. Through the bridge, light from CAT could be fed to one of the instruments placed in the larger dome whenever the 3.6-m telescope was observing with a different instrument. That way both telescopes could work in tandem and benefit from the 3.6-metre telescope’s instruments.