The HELIOS instrument at the ESO 3.6-metre telescope in Chile

HELIOS is an instrument that was installed in April 2018 to feed sunlight via fibre optics to the HARPS (High Accuracy Radial velocity Planet Searcher) spectrograph.

This picture shows a sunset view of the HELIOS solar telescope attached to the catwalk of the ESO 3.6-metre telescope at La Silla. The dome of the decommissioned Coudé Auxiliary Telescpe (CAT) appears at the right.