UTs and ATs

The four 8.2m Unit Telescopes (UTs) — Antu, Kueyen, Melipal and Yepun — can be seen at the bottom of the image in this fisheye photograph of the Paranal Observatory in Chile. Around the top, left and right are three of the four smaller 1.8m diameter Auxiliary Telescopes (ATs). These smaller telescopes are movable, and can work every night as an interferometer, allowing astronomers to see details up to 25 times finer than with the individual telescopes.