An Auxiliary Telescope on the move

This video shows how the Auxiliary Telescopes (AT) move on the VLT platform.

The ATs allow the VLT to operate as an interferometer every night. They are mounted on tracks and can be moved between precisely defined observing positions from where the beams of collected light are combined.

The ATs are very unusual telescopes, as they are self-contained in their ultra-compact protective domes, and travel with their own electronics, ventilation, hydraulics and cooling systems. Each AT has a transporter that lifts the telescope and moves it from one position to the other.