Very Large Telescope

telescope facility in the Atacama Desert, Chile

The Very Large Telescope (VLT) is a telescope operated by the European Southern Observatory. It is on Cerro Paranal in the Atacama Desert of northern Chile.

Very Large Telescope
The four Unit Telescopes that form the VLT together with the four Auxiliary Telescopes (VST at right)
Alternative namesVLT Edit this at Wikidata
Part ofParanal Observatory Edit this on Wikidata
Location(s)Antofagasta Region, Chile
Coordinates24°37′38″S 70°24′15″W / 24.62733°S 70.40417°W / -24.62733; -70.40417 Edit this at Wikidata
OrganizationEuropean Southern Observatory Edit this on Wikidata
Altitude2,635 m (8,645 ft) Edit this at Wikidata
Observing time320 nights per year Edit this on Wikidata
Wavelength300 nm – 20 μm (visible, near- and mid-infrared)
First light1998 (for the first Unit Telescope)
Telescope styleastronomical observatory Edit this on Wikidata
Diameter4 x 8.2-metre Unit Telescopes (UT)
4 x 1.8-metre moveable Auxiliary Telescopes (AT)
Angular resolution0.002 arcsecond Edit this on Wikidata
Focal length120 m (393 ft 8 in) Edit this at Wikidata Edit this at Wikidata
Very Large Telescope is located in Chile
Very Large Telescope
Location of Very Large Telescope



The VLT consists of four separate telescopes, each with a main mirror 8.2 metres across. They are often used separately, but they can be used together to get a very high angular resolution.[1] The observatory also has four movable Auxiliary Telescopes (ATs) of 1.8 m aperture.

It operates at visible and infrared wavelengths. Each individual telescope can detect objects roughly four billion times fainter than can be seen with the naked eye. When all the telescopes are combined, the facility can achieve an angular resolution of about 0.001 arc-second. This is equivalent to roughly two metres at the distance of the Moon.[1]

The VLT is the most productive ground-based facility for astronomy: only the Hubble Space Telescope leads to more scientific papers in observational astronomy.[2]

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.[3]

Auxiliary Telescopes

The Four ATs at Paranal. The Unit Telescopes are in the background

The four smaller 1.8-metre ATs are available and dedicated to interferometry. This allows the VLT to operate every night on visible and infrared wavelengths.[3]



  1. 1.0 1.1 "The Very Large Telescope". ESO. Retrieved 2011-08-05.
  2. Trimble V. & Ceja J.A. (2010). "Productivity and impact of astronomical facilities: a recent sample". Astronomische Nachrichten. 331 (3): 338–345. Bibcode:2010AN....331..338T. doi:10.1002/asna.200911339. S2CID 54516166.
  3. 3.0 3.1 "The Very Large Telescope — the world's most advanced visible-light astronomical observatory handout". ESO. Retrieved 2011-08-05.