Editing Very Large Telescope (section)

{{Short description|Telescope in the Atacama Desert, Chile}}
{{Use dmy dates|date=February 2025}}
{{Infobox telescope
|wavelength = 300 nm – 20 μm ([[Ultraviolet#Subtypes|N-UV]], [[visible light]], NIR, SWIR, MWIR, and LWIR)
|first_light = {{start date and age|1998}} (for the first Unit Telescope)
|diameter = {{plainlist|
*4 × 8.2-metre Unit Telescopes (UT)
*4 × 1.8-metre moveable Auxiliary Telescopes (AT)}}
}}
The '''Very Large Telescope''' ('''VLT''') is an astronomical facility operated since 1998 by the [[European Southern Observatory]], located on [[Cerro Paranal]] in the [[Atacama Desert]] of northern [[Chile]]. It consists of four individual telescopes, each equipped with a [[primary mirror]] that measures {{convert|8.2|m|ft}} in diameter. These [[optical telescope]]s, named ''Antu'', ''Kueyen'', ''Melipal'', and ''Yepun'' (all words for astronomical objects in the [[Mapuche language]]), are generally used separately but can be combined to achieve a very high [[angular resolution]].<ref name="esovlt">{{cite web |title=The Very Large Telescope |url=http://www.eso.org/public/teles-instr/vlt.html |access-date=5 August 2011 |publisher=ESO}}</ref> The VLT array is also complemented by four movable Auxiliary Telescopes (ATs) with {{convert|1.8|m|ft|adj=on}} apertures.

The VLT is capable of observing both [[visible light|visible]] and [[infrared]] [[wavelength]]s. Each individual telescope can detect objects that are roughly four billion times fainter than what can be seen with the [[naked eye]]. When all the telescopes are combined, the facility can achieve an [[angular resolution]] of approximately 0.002&nbsp;arcsecond. In single telescope mode, the angular resolution is about 0.05&nbsp;arcseconds.<ref>{{Cite web|url=https://www.eso.org/public/about-eso/faq/faq-vlt-paranal/|title=FAQ VLT/Paranal|website=eso.org}}</ref>

The VLT is one of the most productive facilities for astronomy, second only to the [[Hubble Space Telescope]] in terms of the number of scientific papers produced from facilities operating at visible wavelengths.<ref>{{Cite journal | bibcode = 2010AN....331..338T | title = Productivity and impact of astronomical facilities: A recent sample | last1 = Trimble | first1 = V. | last2 = Ceja | first2 = J. A. | volume = 331 | date = 2010 | page = 338 | journal = Astronomische Nachrichten | doi = 10.1002/asna.200911339 | issue = 3| s2cid = 54516166 | url = https://cloudfront.escholarship.org/dist/prd/content/qt8kj8693b/qt8kj8693b.pdf }}</ref> Some of the pioneering observations made using the VLT include the first direct image of an [[exoplanet]], the tracking of stars orbiting around the [[supermassive black hole]] at the centre of the [[Milky Way]], and observations of the afterglow of the [[GRB 090423|furthest known gamma-ray burst]].<ref name="vlthandout">{{cite web |title=The Very Large Telescope – The World's Most Advanced Visible-light Astronomical Observatory handout |url=http://www.eso.org/public/products/brochures/vlt_handout/ |access-date=5 August 2011 |publisher=ESO}}</ref>