The ESO 3.6 m Telescope is an optical reflecting

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

run by the

European Southern Observatory The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 mem ...

La Silla Observatory La Silla Observatory is an astronomy, astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are located at the site and are partly maintained by ESO. The obse ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

since 1977, with a clear aperture of about and area. The telescopes uses the

HARPS The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. H ...

instrument and has discovered more than 130

exoplanets An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

. In 2012, it discovered

Alpha Centauri Bb Alpha Centauri Bb (α Cen B b) was a proposed exoplanet orbiting the K-type main-sequence star Alpha Centauri B, located 4.37 light-years from Earth in the southern constellation of Centaurus, but there has not been enough evidence to support ...

, a now-disproven possible planet in the

Alpha Centauri Alpha Centauri ( Latinized from α Centauri and often abbreviated Alpha Cen or α Cen) is a triple star system in the constellation of Centaurus. It consists of 3 stars: Alpha Centauri A (officially Rigil Kentaurus), Alpha Centaur ...

system only 4.4 light-years away. ESO collaborated with

CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gene ...

on building the telescope. It saw first light in 1976 and entered full operations in 1977. When completed it was one of the world's largest optical telescopes. It received an overhaul in 1999 and a new secondary in 2004. The ESO 3.6-metre Telescope has supported many scientific achievements and presented ADONIS, one of the first

adaptive optics Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical tele ...

system available to the astronomical community in the 1980s.

Instruments

Since April 2008, the only instrument on the ESO 3.6 m telescope is HARPS, the

High Accuracy Radial Velocity Planet Searcher The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. H ...

. HARPS is a fibre-fed high resolution

echelle spectrograph An echelle grating (from French ''échelle'', meaning "ladder") is a type of diffraction grating characterised by a relatively low groove density, but a groove shape which is optimized for use at high incidence angles and therefore in high diffract ...

dedicated to the discovery of extrasolar planets. Other instruments on the telescope, now decommissioned, include: * CES: is a spectrograph that provides a resolving power of up to 235,000 in the 346–1028 nm region. * EFOSC2: the ''ESO Faint Object Spectrograph and Camera (v.2)'', is a very versatile instrument for low resolution spectroscopy and imaging. * TIMMI-2: the ''Thermal Infrared MultiMode Instrument'' dedicated to the 3–25 µm spectrum. * ADONIS: is the acronym for ''Adaptive Optics Near Infrared System'', and was a second-generation

system for the astronomical community. More than 40 peer-reviewed scientific articles were published based on this instrument data. ADONIS is the final version of diverse Adaptive Optics (AO) prototypes named Come-on and Come-on +. It was offered in its final version in October 1996 as an official

ESO The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based ast ...

instrument, then decommissioned in 2001. ADONIS was the first AO system offered to a large community of astronomers.

Recent scientific achievements

The ESO 3.6 m telescope has made several scientific discoveries since it saw first light. Recent astronomical achievements were made possible by HARPS, a "top-class" instrument. This include finding the lightest exoplanet known at the time of discovery in,

Gliese 581e Gliese 581e or Gl 581e is an extrasolar planet orbiting within the Gliese 581 system, located approximately 20.4 light-years away from Earth in the Libra constellation. It is the third planet discovered in the system (fourth if the disputed plane ...

, with only twice the mass of the Earth, and the richest planetary system known at the time, with up to seven planets orbiting a Sun-like star. The telescope was also involved in solving a decades-old mystery regarding the mass of Cepheid variable stars. By using the HARPS instrument, astronomers detected for the first time a double star where a pulsating Cepheid variable and another star pass in front of one another, which allows to measure the mass of the Cepheid. The study concluded that the mass prediction coming from the theory of stellar pulsation was correct while the value calculated was at odds with the theory of stellar evolution. The discovery of the extrasolar planet

Gliese 581 c Gliese 581c (Gl 581c or GJ 581c) is a planet orbiting within the Gliese 581 system. It is the second planet discovered in the system and the third in order from the star. With a mass at least 5.5 times that of the Earth, it is classified as a ...

by the team of

Stéphane Udry Stéphane Udry (born 1961 in Sion, Switzerland) is an astronomer at the Geneva Observatory in Switzerland, whose current work is primarily the search for extra-solar planets. He and his team, in 2007, discovered a possibly terrestrial planet in t ...

University of Geneva The University of Geneva (French: ''Université de Genève'') is a public research university located in Geneva, Switzerland. It was founded in 1559 by John Calvin as a theological seminary. It remained focused on theology until the 17th centu ...

's Observatory in

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

was announced on April 24, 2007. The team used the telescope's

spectrograph, and employed the

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

technique to identify the planet's influence on the star. By 2009, the telescope was used to discover 75

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

candidates. In 2011, another 50 exoplanet candidates were announced.

Contemporaries on commissioning

Gallery

Telescope and site

Image: 3.6-m Telescope at La Silla.jpg, The ESO 3.6-metre telescope. Image: 3,6-m Telescope at La Silla.jpg, The road to the telescope at La Silla. Image: LaSillaByNight2.jpg,

Euler Telescope Leonhard Euler Telescope, or the Swiss EULER Telescope, is a national, fully automatic reflecting telescope, built and operated by the Geneva Observatory. It is located at an altitude of at ESO's La Silla Observatory site in the Chilean Norte ...

and the ESO 3.6 m Telescope (background). Image: La Silla 3.6m telescope.jpg, Panoramic view of the ESO 3.6-metre telescope's dome. Image: ESO-The Milky Way above La Silla-phot-27-04-hires.jpg,

La Silla La Silla may refer to: * La Silla Observatory, an astronomical observatory in Chile * Cerro de la Silla, a mountain and natural monument located within the metropolitan area of the city of Monterrey, Nuevo León, in northeastern Mexico. * La Sill ...

—Early evening scenery ''(in the distant right: the ESO 3.6 m T.)'' Image:Construction of the ESO 3.6-metre telescope.jpg, Construction of the ESO 3.6-metre telescope.

Images from telescope

Image:NGC 2207 and IC 2163.jpg,

NGC 2207 In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000 ( 21st to 30th centuries). Ongoing futures studies seek to understand what is l ...

and

IC 2163 In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000 ( 21st to 30th centuries). Ongoing futures studies seek to understand what is ...

, two interacting galaxies ''(captured by EFOSC2)'' Image: NGC 520.tif, NGC 520, colliding galaxies

References

External links

*
ESO 3.6m homepage

ESO homepage

ADONIS ESO webpage
{{European Southern Observatory Optical telescopes European Southern Observatory