1024px-Aerial View of the VLTI with Tunnels Superimposed

Aerial view of the observing platform on the top of Cerro Paranal, with the four enclosures for the 8.2-m Unit Telescopes (UTs) and various installations for the VLT Interferometer (VLTI).

The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranalin the Atacama Desert of northern Chile. The VLT consists of four individual telescopes, each with a primary mirror 8.2 m across, which are generally used separately but can be used together to achieve very high angular resolution.[1] The four separate optical telescopes are known as Antu, Kueyen, Melipal and Yepun, which are all words for astronomical objects in the Mapuche language. The telescopes form an array which is complemented by four movable Auxiliary Telescopes (ATs) of 1.8 m aperture.


The VLT operates at visible light and infrared wavelengths. Each individual telescope can detect objects roughly four billion times fainter than can be detected with the naked eye, and when all the telescopes are combined, the facility can achieve an angular resolution of about 0.001 arc-second. In single telescope mode of operation angular resolution is about 0.05 arc-second.[2]


The VLT is the most productive ground-based facility for astronomy, with only the Hubble Space Telescope generating more scientific papers among facilities operating at visible wavelengths.[3] Among the pioneering observations carried out using the VLT are the first direct image of an exoplanet, the tracking of individual stars moving around the supermassive black hole at the centre of the Milky Way, and observations of the afterglow of the furthest known gamma-ray burst.[4]


  1. "The Very Large Telescope". ESO. Retrieved 2011-08-05. 
  3. Trimble, V.; Ceja, J. A. (2010). "Productivity and impact of astronomical facilities: A recent sample". Astronomische Nachrichten 331 (3): 338. doi:10.1002/asna.200911339. Bibcode2010AN....331..338T. 
  4. "The Very Large Telescope — The World’s Most Advanced Visible-light Astronomical Observatory handout". ESO. Retrieved 2011-08-05.