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
astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...
. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs about 730 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern
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 ...
.
ESO has built and operated some of the largest and most technologically advanced
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 ...
s. These include the 3.6 m
New Technology Telescope
The New Technology Telescope or NTT is a 3.58-metre Ritchey–Chrétien telescope operated by the European Southern Observatory. It began operations in 1989. It is located in Chile at the La Silla Observatory and was an early pioneer in the use of ...
, an early pioneer in the use of
active optics
Active optics is a technology used with reflecting telescopes developed in the 1980s, which actively shapes a telescope's mirrors to prevent deformation due to external influences such as wind, temperature, and mechanical stress. Without active op ...
, and the
Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, ...
(VLT), which consists of four individual 8.2 m telescopes and four smaller auxiliary telescopes which can all work together or separately. The
Atacama Large Millimeter Array
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The a ...
observes the
universe
The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. Acc ...
in the
millimetre and submillimetre wavelength ranges, and is the world's largest ground-based astronomy project to date. It was completed in March 2013 in an international collaboration by Europe (represented by ESO), North America, East Asia and Chile.
Currently under construction is the
Extremely Large Telescope
The Extremely Large Telescope (ELT) is an astronomical observatory currently under construction. When completed, it is planned to be the world's largest optical/near-infrared extremely large telescope. Part of the European Southern Observator ...
. It will use a 39.3-metre-diameter
segmented mirror
A segmented mirror is an array of smaller mirrors designed to act as segments of a single large curved mirror. The segments can be either spherical or asymmetric (if they are part of a larger parabolic reflector). They are used as objectives for ...
, and become the
world's largest optical reflecting telescope when operational in 2024. Its light-gathering power will allow detailed studies of planets around other stars, the first objects in the universe,
supermassive black hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical obj ...
s, and the nature and distribution of the
dark matter
Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not ab ...
and
dark energy
In physical cosmology and astronomy, dark energy is an unknown form of energy that affects the universe on the largest scales. The first observational evidence for its existence came from measurements of supernovas, which showed that the univer ...
which dominate the universe.
ESO's observing facilities have made astronomical discoveries and produced several
astronomical catalogues
An astronomical catalog or catalogue is a list or tabulation of astronomical objects, typically grouped together because they share a common type, morphology, origin, means of detection, or method of discovery. The oldest and largest are star c ...
. Its findings include the discovery of the most distant
gamma-ray burst
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milli ...
and evidence for a
black hole
A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...
at the centre of the
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
. In 2004, the VLT allowed astronomers to obtain the first picture of an
extrasolar planet
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 ...
(
2M1207b
2M1207b is a planetary-mass object orbiting the brown dwarf 2M1207, in the constellation Centaurus, approximately 170 light-years from Earth. ) orbiting a
brown dwarf
Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...
173 light-years away. The High Accuracy Radial Velocity Planet Searcher (
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 installed on the older ESO 3.6 m telescope led to the discovery of extrasolar planets, including
Gliese 581c
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 s ...
—one of the smallest planets seen outside the
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
.
History
The idea that European astronomers should establish a common large observatory was broached by
Walter Baade
Wilhelm Heinrich Walter Baade (March 24, 1893 – June 25, 1960) was a German astronomer who worked in the United States from 1931 to 1959.
Biography
The son of a teacher, Baade finished school in 1912. He then studied maths, physics and astro ...
and
Jan Oort
Jan Hendrik Oort ( or ; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy. His ''New York Times'' obituary ...
at the
Leiden Observatory
Leiden Observatory ( nl, Sterrewacht Leiden) is an astronomical institute of Leiden University, in the Netherlands. Established in 1633 to house the quadrant of Rudolph Snellius, it is the oldest operating university observatory in the world, with ...
in the Netherlands in spring 1953. It was pursued by Oort, who gathered a group of astronomers in Leiden to consider it on June 21 that year. Immediately thereafter, the subject was further discussed at the Groningen conference in the Netherlands. On January 26, 1954, an ESO declaration was signed by astronomers from six European countries expressing the wish that a joint European observatory be established in the southern hemisphere.
At the time, all
reflector telescope
A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternati ...
s with an
aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.
An opt ...
of 2 metres or more were located in the northern hemisphere. The decision to build the observatory in the southern hemisphere resulted from the necessity of observing the southern sky; some research subjects (such as the central parts of the
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
and the
Magellanic Clouds
The Magellanic Clouds (''Magellanic system'' or ''Nubeculae Magellani'') are two irregular dwarf galaxies in the southern celestial hemisphere. Orbiting the Milky Way galaxy, these satellite galaxies are members of the Local Group. Because both ...
) were accessible only from the southern hemisphere.
Although it was initially planned to set up telescopes in South Africa (where several European observatories were located), tests from 1955 to 1963 demonstrated that a site in the
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...
was preferable. On November 15, 1963
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 ...
was chosen as the site for ESO's observatory. The decision was preceded by the ESO Convention, signed 5 October 1962 by Belgium, Germany, France, the Netherlands and Sweden.
Otto Heckmann
Otto Hermann Leopold Heckmann (June 23, 1901 – May 13, 1983) was a German astronomer.
He directed the Hamburg Observatory from 1941 to 1962, after which he became the first director of the European Southern Observatory. He actively contrib ...
was nominated as the organisation's first director general on 1 November 1962.
![Directors General of ESO – First Stone Ceremony](https://upload.wikimedia.org/wikipedia/commons/2/2c/Directors_General_of_ESO_%E2%80%93_First_Stone_Ceremony.jpg)
A preliminary proposal for a convention of astronomy organisations in these five countries was drafted in 1954. Although some amendments were made in the initial document, the convention proceeded slowly until 1960 when it was discussed during that year's committee meeting. The new draft was examined in detail, and a council member of
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 ...
(the European Organization for Nuclear Research) highlighted the need for a convention between governments (in addition to organisations).
The convention and government involvement became pressing due to rapidly rising costs of site-testing expeditions. The final 1962 version was largely adopted from the CERN convention, due to similarities between the organisations and the dual membership of some members.
In 1966, the first ESO telescope at the La Silla site in Chile began operating.
Because CERN (like ESO) had sophisticated instrumentation, the astronomy organisation frequently turned to the nuclear-research body for advice and a collaborative agreement between ESO and CERN was signed in 1970. Several months later, ESO's telescope division moved into a CERN building in
Geneva
Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...
and ESO's Sky Atlas Laboratory was established on CERN property. ESO's European departments moved into the new ESO headquarters in
Garching
Garching bei München (''Garching near Munich'') or Garching is a town in Bavaria, Germany, near Munich. It is the home of several research institutes and university departments on its campus. It became a city on 14 September 1990.
Location
The ...
(near
Munich
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the States of Germany, German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the List of cities in Germany by popu ...
), Germany in 1980.
Member states
Chilean observation sites
Although ESO is headquartered in Germany, its telescopes and observatories are in northern
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 ...
, where the organisation operates advanced
ground-based astronomical facilities:
*
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 ...
, which hosts the
New Technology Telescope
The New Technology Telescope or NTT is a 3.58-metre Ritchey–Chrétien telescope operated by the European Southern Observatory. It began operations in 1989. It is located in Chile at the La Silla Observatory and was an early pioneer in the use of ...
(NTT)
*
Paranal, where the
Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, ...
(VLT) is located
*
Llano de Chajnantor, which hosts the APEX (
Atacama Pathfinder Experiment
The Atacama Pathfinder Experiment (APEX) is a radio telescope 5,064 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert in northern Chile, 50 km east of San Pedro de Atacama built and operated by 3 European r ...
)
submillimetre telescope and where ALMA, the
Atacama Large Millimeter/submillimeter Array
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The arr ...
, is located
These are among the best locations for astronomical observations in the southern hemisphere. An ESO project is the
Extremely Large Telescope
The Extremely Large Telescope (ELT) is an astronomical observatory currently under construction. When completed, it is planned to be the world's largest optical/near-infrared extremely large telescope. Part of the European Southern Observator ...
(ELT), a 40-metre-class telescope based on a five-mirror design and the formerly planned
Overwhelmingly Large Telescope
The Overwhelmingly Large Telescope (OWL) was a conceptual design by the European Southern Observatory (ESO) organization for an extremely large telescope, which was intended to have a single aperture of 100 meters in diameter. Because of the com ...
. The ELT will be the largest visible and near-infrared telescope in the world. ESO began its design in early 2006, and aimed to begin construction in 2012.
Construction work at the ELT site started in June 2014.
As decided by the ESO council on 26 April 2010, a fourth site (
Cerro Armazones
Cerro Armazones is a mountain located in the Sierra Vicuña Mackenna of the Chilean Coast Range, approximately south-east of Antofagasta in the Antofagasta Region, Chile. Before construction started on the European Extremely Large Telescope, th ...
) is to be home to ELT.
Each year about 2,000 requests are made for the use of ESO telescopes, for four to six times more nights than are available. Observations made with these instruments appear in a number of peer-reviewed publications annually; in 2017, more than 1,000 reviewed papers based on ESO data were published.
ESO telescopes generate large amounts of data at a high rate, which are stored in a permanent archive facility at ESO headquarters. The archive contains more than 1.5 million images (or spectra) with a total volume of about 65 terabytes (65,000,000,000,000 bytes) of data.
La Silla
![Observatorio la silla1](https://upload.wikimedia.org/wikipedia/commons/4/48/Observatorio_la_silla1.JPG)
La Silla, located in the southern
Atacama Desert
The Atacama Desert ( es, Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in the ...
north of
Santiago de Chile
Santiago (, ; ), also known as Santiago de Chile, is the capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated region, the Santiago Metropolitan Region, whose ...
at an altitude of , is the home of ESO's original observation site. Like other observatories in the area, La Silla is far from sources of
light pollution
Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day ...
and has one of the darkest night skies on Earth. In La Silla, ESO operates three telescopes: a 3.6-metre telescope, the New Technology Telescope (NTT) and the 2.2-metre Max-Planck-ESO Telescope.
The observatory hosts visitor instruments, attached to a telescope for the duration of an observational run and then removed. La Silla also hosts national telescopes, such as the 1.2-metre Swiss and the 1.5-metre Danish telescopes.
About 300 reviewed publications annually are attributable to the work of the observatory. Discoveries made with La Silla telescopes include the
HARPS-spectrograph detection of the planets orbiting within the
Gliese 581 planetary system
Gliese 581 () is a red dwarf star of spectral type M3V at the center of the Gliese 581 planetary system, about 20 light years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it is t ...
, which contains the first known rocky planet in a habitable zone outside the solar system. Several telescopes at La Silla played a role in linking
gamma-ray burst
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milli ...
s, the most energetic explosions in the universe since the
Big Bang
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...
, with the explosions of massive stars. The ESO La Silla Observatory also played a role in the study of supernova
SN 1987A
SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately from Earth and was the closest observed supernova since Kepler's Supernova. 1987A's light reached Earth on Feb ...
.
ESO 3.6-metre telescope
![3](https://upload.wikimedia.org/wikipedia/commons/b/b8/3.6-m_Telescope_at_La_Silla.jpg)
The ESO 3.6-metre telescope began operations in 1977. It has been upgraded, including the installation of a new
secondary mirror
A secondary mirror (or secondary) is the second deflecting or focusing mirror element in a reflecting telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. Secondary mirr ...
. The conventionally designed
horseshoe-mount telescope was primarily used for
infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...
; it now hosts the HARPS spectrograph, used in search of
extra-solar planets
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 ...
and for
asteroseismology
Asteroseismology or astroseismology is the study of oscillations in stars. Stars have many resonant modes and frequencies, and the path of sound waves passing through a star depends on the speed of sound, which in turn depends on local temperature ...
. The telescope was designed for very high long-term
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 ...
accuracy (on the order of 1 m/s).
New Technology Telescope
![The NTT Enclosure](https://upload.wikimedia.org/wikipedia/commons/e/e2/The_NTT_Enclosure.jpg)
The New Technology Telescope (NTT) is an
altazimuth, 3.58-metre
Ritchey–Chrétien telescope
A Ritchey–Chrétien telescope (RCT or simply RC) is a specialized variant of the Cassegrain telescope that has a hyperbolic primary mirror and a hyperbolic secondary mirror designed to eliminate off-axis optical errors (coma). The RCT has a wi ...
, inaugurated in 1989 and the first in the world with a computer-controlled main mirror. The flexible mirror's shape is adjusted during observation to preserve optimal image quality. The secondary mirror position is also adjustable in three directions. This technology (developed by ESO and known as
active optics
Active optics is a technology used with reflecting telescopes developed in the 1980s, which actively shapes a telescope's mirrors to prevent deformation due to external influences such as wind, temperature, and mechanical stress. Without active op ...
) is now applied to all major telescopes, including the VLT and the future ELT.
The design of the octagonal enclosure housing the NTT is innovative. The telescope dome is relatively small and ventilated by a system of flaps directing airflow smoothly across the mirror, reducing turbulence and resulting in sharper images.
MPG/ESO 2.2-metre telescope
The 2.2-metre telescope has been in operation at La Silla since early 1984, and is on indefinite loan to ESO from the
Max Planck Society
The Max Planck Society for the Advancement of Science (german: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) is a formally independent non-governmental and non-profit association of German research institutes. ...
(''Max-Planck-Gesellschaft zur Förderung der Wissenschaften'', or MPG, in German). Telescope time is shared between MPG and ESO observing programmes, while operation and maintenance of the telescope are ESO's responsibility.
Its instrumentation includes a 67-million-pixel wide-field imager (WFI) with a
field of view
The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation.
Humans a ...
as large as the full moon, which has taken many images of celestial objects. Other instruments used are
GROND
The Gamma-Ray Burst Optical/Near-Infrared Detector (GROND) is an imaging instrument used to investigate Gamma-Ray Burst afterglows and for doing follow-up observations on exoplanets using transit photometry.
It is operated at the 2.2-metre MPG/E ...
(Gamma-Ray Burst Optical Near-Infrared Detector), which seeks the afterglow of gamma-ray bursts—the most powerful explosions in the universe, and the high-resolution spectrograph FEROS (Fiber-fed Extended Range Optical Spectrograph), used to make detailed studies of stars.
Other telescopes
La Silla also hosts several national and project telescopes not operated by ESO. Among them are the Swiss Euler Telescope, the Danish National Telescope and the REM, TRAPPIST and TAROT telescopes.
* The
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 ...
is a 1.2-metre telescope built and operated by the
Geneva Observatory
The Geneva Observatory (french: Observatoire de Genève, german: Observatorium von Genf) is an astronomical observatory at Sauverny (CH) in the municipality of Versoix, Canton of Geneva, in Switzerland. It shares its buildings with the astronomy ...
in Switzerland. It is used to conduct high-precision radial velocity measurements primarily used in the search for large extrasolar planets in the southern celestial hemisphere. Its first discovery was a planet orbiting
Gliese 86
Gliese 86 (13 G. Eridani, HD 13445) is a K-type main-sequence star approximately 35 light-years away in the constellation of Eridanus. It has been confirmed that a white dwarf orbits the primary star. In 1998 the European Southern Observ ...
. Other observing programmes focus on
variable star
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as ...
s,
asteroseismology
Asteroseismology or astroseismology is the study of oscillations in stars. Stars have many resonant modes and frequencies, and the path of sound waves passing through a star depends on the speed of sound, which in turn depends on local temperature ...
, gamma-ray bursts, monitoring
active galactic nuclei
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not prod ...
(AGN) and
gravitational lens
A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...
es.
* The 1.54-metre ''Danish National Telescope'' was built by
Grubb-Parsons and has been in use at La Silla since 1979. The telescope has an
off-axis mount, and the optics are a Ritchey-Chrétien design. Because of the telescope's mount and limited space inside the dome, it has significant pointing restrictions.
![The Great Dane](https://upload.wikimedia.org/wikipedia/commons/5/5a/The_Great_Dane.jpg)
* The
Rapid Eye Mount telescope
The Rapid Eye Mount telescope (REM) is a fully automatic, 60 cm aperture telescope located at ESO's La Silla Observatory at 2,400 metres altitude on the edge of the Atacama Desert in Chile. The telescope's aim is to catch the afterglows of gam ...
is a small rapid-reaction automatic telescope with a primary mirror. The telescope, in an
altazimuth mount
An altazimuth mount or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two perpendicular axes – one vertical and the other horizontal. Rotation about the vertical axis varies the azimuth (compass bea ...
, began operation in October 2002. The primary purpose of the telescope is to follow the afterglow of the GRBs detected by the
Swift Gamma-Ray Burst Mission
Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Explorer, is a NASA three-telescope space observatory for studying gamma-ray bursts (GRBs) and monitoring the afterglow in X-ray, and UV/Visible light at the location o ...
satellite.
* The Belgian
TRAPPIST
The Trappists, officially known as the Order of Cistercians of the Strict Observance ( la, Ordo Cisterciensis Strictioris Observantiae, abbreviated as OCSO) and originally named the Order of Reformed Cistercians of Our Lady of La Trappe, are a ...
is a joint venture between the
University of Liège
The University of Liège (french: Université de Liège), or ULiège, is a major public university of the French Community of Belgium based in Liège, Wallonia, Belgium. Its official language is French. As of 2020, ULiège is ranked in the 301 ...
and Geneva Observatory. The 0.60-metre telescope is specialised in
comets
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are ...
, exoplanets, and was one of the few telescopes that observed a
stellar occultation
Stellar means anything related to one or more stars (''stella''). The term may also refer to:
Arts, entertainment, and media
* ''Stellar'' (magazine), an Irish lifestyle and fashion magazine
* Stellar Loussier, a character from ''Mobile Suit Gun ...
of the dwarf planet
Eris, revealing that it may be smaller than
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
.
[Newscientist.com]
Kelly Beatty – Former 'tenth planet' may be smaller than Pluto
November 2010
* The ''Quick-action telescope for transient objects'',
TAROT
The tarot (, first known as '' trionfi'' and later as ''tarocchi'' or ''tarocks'') is a pack of playing cards, used from at least the mid-15th century in various parts of Europe to play card games such as Tarocchini. From their Italian roots, ...
, is a very fast-moving optical robotic telescope able to observe a gamma-ray burst from its beginning. Satellites detecting GRBs send signals to TAROT, which can provide a
sub-arc second position to the astronomical community. Data from the TAROT telescope is also useful in studying the evolution of GRBs, the physics of a
fireball
Fireball may refer to:
Science
* Fireball (meteor), a brighter-than-usual meteor
* Ball lightning, an atmospheric electrical phenomenon
* ''Bassia scoparia'', a plant species
Arts and entertainment Films
* ''The Fireball'', a 1950 film starring ...
and its surrounding material. It is operated from the
Haute-Provence Observatory
The Haute-Provence Observatory (OHP, french: Observatoire de Haute-Provence) is an astronomical observatory in the southeast of France, about 90 km east of Avignon and 100 km north of Marseille. It was established in 1937 as a national ...
in France.
Paranal
The Paranal Observatory is located atop
Cerro Paranal
Cerro Paranal is a mountain in the Atacama Desert of northern Chile and is the home of the Paranal Observatory. Prior to the construction of the observatory, the summit was a horizontal control point with an elevation of ; now it is above sea ...
in the Atacama Desert in northern Chile. Cerro Paranal is a mountain about south of
Antofagasta
Antofagasta () is a port city in northern Chile, about north of Santiago. It is the capital of Antofagasta Province and Antofagasta Region. According to the 2015 census, the city has a population of 402,669.
After the Spanish American wars ...
and from the Pacific coast.
The observatory has seven major telescopes operating in visible and infrared light: the four telescopes of the Very Large Telescope, the VLT Survey Telescope (VST) and the Visible and Infrared Survey Telescope for Astronomy. In addition, there are four auxiliary telescopes forming an array used for
interferometric
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber op ...
observations. In March 2008, Paranal was the location for several scenes of the 22nd James Bond film, ''
Quantum of Solace
''Quantum of Solace'' is a 2008 spy film and the twenty-second in the List of James Bond films, ''James Bond'' series produced by Eon Productions. It is the sequel to Casino Royale (2006 film), ''Casino Royale'' (2006). Directed by Marc Forst ...
''.
Very Large Telescope
The main facility at Paranal is the VLT, which consists of four nearly identical unit telescopes (UTs), each hosting two or three instruments. These large telescopes can also work together in groups of two or three as a giant
interferometer
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber op ...
. The ESO Very Large Telescope Interferometer (VLTI) allows astronomers to see details up to 25 times finer than those seen with the individual telescopes. The light beams are combined in the VLTI with a complex system of mirrors in tunnels, where the light paths must diverge less than 1/1000 mm over 100 metres. The VLTI can achieve an
angular resolution
Angular resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution. ...
of milliarcseconds, equivalent to the ability to see the headlights of a car on the moon.
The first of the UTs had its
first light in May 1998, and was offered to the astronomical community on 1 April 1999.
The other telescopes followed suit in 1999 and 2000, making the VLT fully operational. Four 1.8-metre auxiliary telescopes (ATs), installed between 2004 and 2007, have been added to the VLTI for accessibility when the UTs are used for other projects.
Data from the VLT have led to the publication of an average of more than one peer-reviewed scientific paper per day; in 2017, over 600 reviewed scientific papers were published based on VLT data.
The VLT's scientific discoveries include imaging an extrasolar planet, tracking individual stars moving around the
supermassive black hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical obj ...
at the centre of the Milky Way
and observing the afterglow of the furthest known gamma-ray burst.
At the Paranal inauguration in March 1999, names of celestial objects in the
Mapuche language
Mapuche (, Mapuche & Spanish: , or Mapudungun; from ' 'land' and ' 'speak, speech') is an Araucanian language related to Huilliche spoken in south-central Chile and west-central Argentina by the Mapuche people (from ''mapu'' 'land' and ''che ...
were chosen to replace the technical designations of the four VLT Unit Telescopes (UT1–UT4). An essay contest was prior arranged for schoolchildren in the region concerning the meaning of these names which attracted many entries dealing with the cultural heritage of ESO's host country. A 17-year-old adolescent from
Chuquicamata
Chuquicamata ( ; referred to as Chuqui for short) is the largest open pit copper mine in terms of excavated volume in the world. It is located in the north of Chile, just outside Calama, at above sea level. It is northeast of Antofagasta and n ...
, near
Calama, submitted the winning essay and was awarded an amateur telescope during the inauguration. The four unit telescopes, UT1, UT2, UT3 and UT4, are since known as ''Antu'' (sun), ''Kueyen'' (moon), ''Melipal'' (Southern Cross), and ''Yepun'' (Evening Star), with the latter having been originally mistranslated as "Sirius", instead of "Venus".
Survey telescopes
Visible and Infrared Survey Telescope for Astronomy
The VISTA (Visible and Infrared Survey Telescope for Astronomy) is a wide-field reflecting telescope with a 4.1 metre mirror, located at the Paranal Observatory in Chile. It is operated by the European Southern Observatory and started science op ...
(VISTA) is housed on the peak adjacent to the one hosting the VLT, sharing observational conditions. VISTA's main mirror is across, a highly curved mirror for its size and quality. Its deviations from a perfect surface are less than a few thousandths the thickness of a human hair, and its construction and polishing presented a challenge.
VISTA was conceived and developed by a consortium of 18 universities in the United Kingdom led by
Queen Mary, University of London
, mottoeng = With united powers
, established = 1785 – The London Hospital Medical College1843 – St Bartholomew's Hospital Medical College1882 – Westfield College1887 – East London College/Queen Mary College
, type = Public researc ...
, and it became an in-kind contribution to ESO as part of the UK's ratification agreement. The telescope's design and construction were managed by the Science and Technology Facilities Council's
UK Astronomy Technology Centre
The UK Astronomy Technology Centre (UK ATC) is based at the Royal Observatory in Edinburgh, Scotland, and is part of the Science and Technology Facilities Council.
The UK ATC designs, builds, develops, tests and manages major instrumentation ...
(STFC, UK ATC). Provisional acceptance of VISTA was formally granted by ESO at the December 2009 ceremony at ESO headquarters in Garching, which was attended by representatives of Queen Mary, University of London and STFC. Since then the telescope has been operated by ESO, capturing quality images since it began operation.
The
VLT Survey Telescope
The VLT Survey Telescope (VST) is a telescope located at ESO’s Paranal Observatory in the Atacama Desert of northern Chile. It is housed in an enclosure immediately adjacent to the four Very Large Telescope (VLT) Unit Telescopes on the summit o ...
(VST) is a state-of-the-art, telescope equipped with OmegaCAM, a 268-megapixel CCD camera with a field of view four times the area of the full moon. It complements VISTA by surveying the sky in visible light. The VST (which became operational in 2011) is the result of a joint venture between ESO and the
Astronomical Observatory of Capodimonte
The Astronomical Observatory of Capodimonte ( it, Osservatorio Astronomico di Capodimonte, italic=no) is the Neapolitan department of Istituto Nazionale di Astrofisica (National Institute for Astrophysics, INAF), the most important Italian institu ...
(Naples), a research centre at the Italian National Institute for Astrophysics
INAF
The National Institute for Astrophysics ( it, Istituto Nazionale di Astrofisica, or INAF) is an Italian research institute in astronomy and astrophysics, founded in 1999. INAF funds and operates twenty separate research facilities, which in turn e ...
.
The scientific goals of both surveys range from the nature of dark energy to assessing
near-Earth object
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
s. Teams of European astronomers will conduct the surveys; some will cover most of the southern sky, while others will focus on smaller areas. VISTA and the VST are expected to produce large amounts of data; a single picture taken by VISTA has 67 megapixels, and images from OmegaCam (on the VST) will have 268 megapixels. The two survey telescopes collect more data every night than all the other instruments on the VLT combined. The VST and VISTA produce more than 100 terabytes of data per year.
Llano de Chajnantor
The Llano de Chajnantor is a plateau in the Atacama Desert, about east of
San Pedro de Atacama
San Pedro de Atacama is a Chilean town and commune in El Loa Province, Antofagasta Region. It is located east of Antofagasta, some 106 km (60 mi) southeast of Calama and the Chuquicamata copper mine, overlooking the Licancabur volcano. ...
. The site is higher than the
Mauna Kea Observatory
The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are located ...
and higher than the
Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, ...
on
Cerro Paranal
Cerro Paranal is a mountain in the Atacama Desert of northern Chile and is the home of the Paranal Observatory. Prior to the construction of the observatory, the summit was a horizontal control point with an elevation of ; now it is above sea ...
. It is dry and inhospitable to humans, but a good site for
submillimetre astronomy
Submillimetre astronomy or submillimeter astronomy (see spelling differences) is the branch of observational astronomy that is conducted at submillimetre wavelengths (i.e., terahertz radiation) of the electromagnetic spectrum. Astronomers plac ...
; because
water vapour
(99.9839 °C)
, -
, Boiling point
,
, -
, specific gas constant
, 461.5 J/( kg·K)
, -
, Heat of vaporization
, 2.27 MJ/kg
, -
, Heat capacity
, 1.864 kJ/(kg·K)
Water vapor, water vapour or aqueous vapor is the gaseous pha ...
molecules in
Earth's atmosphere
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...
absorb and attenuate
submillimetre radiation
Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency
(THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the ITU-designated band of frequ ...
, a dry site is required for this type of
radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming f ...
. The telescopes are:
*
Atacama Cosmology Telescope
The Atacama Cosmology Telescope (ACT) is a cosmological millimeter-wave telescope located on Cerro Toco in the Atacama Desert in the north of Chile. ACT makes high-sensitivity, arcminute resolution, microwave-wavelength surveys of the sky in ord ...
(ACT; not operated by ESO)
*
Atacama Pathfinder Experiment
The Atacama Pathfinder Experiment (APEX) is a radio telescope 5,064 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert in northern Chile, 50 km east of San Pedro de Atacama built and operated by 3 European r ...
*
Atacama Large Millimeter Array
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The a ...
*
Q/U Imaging Experiment (QUIET; not operated by ESO)
*
POLARBEAR
POLARBEAR (POLARization of the Background Radiation) is a cosmic microwave background polarization experiment located in the Atacama Desert of northern Chile in the Antofagasta Region. The POLARBEAR experiment is mounted on the Huan Tran Telescope ...
(on the Huan Tran Telescope; not operated by ESO)
APEX and ALMA are telescopes designed for millimetre and submillimetre astronomy. This type of astronomy is a relatively unexplored frontier, revealing a universe which cannot be seen in more-familiar visible or infrared light and ideal for studying the "cold universe"; light at these wavelengths shines from vast cold clouds in interstellar space at temperatures only a few tens of degrees above
absolute zero
Absolute zero is the lowest limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as zero kelvin. The fundamental particles of nature have minimum vibration ...
. Astronomers use this light to study the chemical and physical conditions in these
molecular cloud
A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen ...
s, the dense regions of gas and cosmic dust where new stars are being born. Seen in visible light, these regions of the universe are often dark and obscure due to dust; however, they shine brightly in the millimetre and submillimetre portions of the
electromagnetic spectrum
The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.
The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from ...
. This wavelength range is also ideal for studying some of the earliest (and most distant) galaxies in the universe, whose light has been
redshift
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...
ed into longer wavelengths from the expansion of the universe.
Atacama Pathfinder Experiment
The Atacama Pathfinder Experiment telescope is operated by ESO in collaboration with the
Max Planck Institute for Radio Astronomy
The Max Planck Institute for Radio Astronomy (MPIfRA) (German: ''Max-Planck-Institut für Radioastronomie'') is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).
History
By com ...
in
Bonn
The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ruhr r ...
, Germany and the
Onsala Space Observatory
Onsala Space Observatory (OSO), the Swedish National Facility for Radio Astronomy, provides scientists with equipment to study the Earth and the rest of the Universe. The observatory operates two radio telescopes in Onsala, 45 km south of Got ...
in
Onsala
Onsala () is a urban areas of Sweden, locality situated in Kungsbacka Municipality, Halland County, Sweden, with 11,951 inhabitants in 2010. It is also a 14 km long peninsula on the west coast of Sweden, facing Kattegat, south of Gothenburg. ...
, Sweden. It is a -diameter telescope operating at millimetre and submillimetre wavelengths, the largest of its kind in the southern hemisphere. APEX is a precursor of ALMA (the Atacama Large Millimeter Array), an
astronomical interferometer
An astronomical interferometer or telescope array is a set of separate telescopes, mirror segments, or radio telescope antenna (radio), antennas that work together as a single telescope to provide higher resolution images of astronomical objects ...
which ESO and its international partners is building on the Chajnantor plateau. APEX is based on a prototype ALMA antenna that is modified to be operated as single dish
radio telescope
A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency ...
.
Atacama Large Millimeter/submillimeter Array
ALMA is an astronomical interferometer of innovative design, initially composed of 66 high-precision antennas and operating at wavelengths of 0.3 to 3.6 mm. Its main array will have 50 antennas acting as a single
interferometer
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber op ...
. An additional compact array of four 12-metre and twelve antennas is also planned. The antennas can be arranged across the desert plateau over distances from 150 metres to , which will give ALMA a variable "zoom". The array will be able to probe the universe at millimetre and submillimeter wavelengths with unprecedented sensitivity and resolution, with vision up to ten times sharper than the
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...
. These images will complement those made with the
VLT Interferometer
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, ...
. ALMA is a collaboration between East Asia (Japan and
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
), Europe (ESO), North America (USA and Canada) and Chile.
The scientific goals of ALMA include studying the origin and formation of stars, galaxies, and planets with observations of molecular gas and dust, studying distant galaxies towards the edge of the observable universe and studying
relic radiation from the
Big Bang
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...
. A call for ALMA science proposals was issued on 31 March 2011, and early observations began on 3 October.
ESO telescopes: research and discoveries
Search for extrasolar planets
![The Very Large Telescope and the star system Alpha Centauri](https://upload.wikimedia.org/wikipedia/commons/d/d2/The_Very_Large_Telescope_and_the_star_system_Alpha_Centauri.jpg)
"Is there life elsewhere in the universe?" is one of humankind's most profound unanswered questions. A step in the attempt to answer this question is the search for planets outside the Solar System. ESO's observatories are equipped with an arsenal of instruments for finding, studying, and monitoring
extrasolar planet
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 ...
s. In 2004, the Very Large Telescope detected a faint glow from an apparent planet orbiting a star about 200 light-years from earth. A year later, this detection was confirmed as the first picture of an exoplanet ever recorded. Although the planet is large (five times more massive than
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
), this observation is a first step toward identifying the physical structure and chemical composition of exoplanets.
Despite the fact that planets seem very common in the universe they are tiny, faint objects at cosmic scales; this makes their detection difficult with current technology. For this reason, most exoplanets have been detected with indirect methods. Of these, the most successful has been the
radial velocity method
Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in t ...
. HARPS (the High Accuracy Radial-velocity Planet Searcher) has allowed the discovery of a number of planets with masses below that of
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
orbiting nearby stars. However, few of these planets are among the smallest ever discovered, or reside in its star's
habitable zone
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Kas ...
. The possibility exists that one of these planets is covered by oceans; this discovery is an encouraging result in the search for planets which could support life.
The Danish 1.54-metre telescope at La Silla participated in the discovery of one of the most Earth-like planets found to date. The planet, detected using the
microlensing
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronomers ...
technique and about five times as massive as Earth, circles its parent star in about 10 years and most certainly has a rocky and icy surface.
In 2017, Breakthrough Initiatives and the European Southern Observatory (ESO) entered a collaboration
to enable and implement a search for habitable planets in the nearby star system, Alpha Centauri. The agreement involves Breakthrough Initiatives providing funding for an upgrade to the VISIR (VLT Imager and Spectrometer for mid-Infrared) instrument on ESO's
Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, ...
(VLT) in Chile. This upgrade will greatly increase the likelihood of planet detection in the system.
In August 2016, the European Southern Observatory announced the detection of a planet orbiting the third star in the
Alpha Centauri system
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 Centauri ...
,
Proxima Centauri
Proxima Centauri is a small, low-mass star located away from the Sun in the southern constellation of Centaurus. Its Latin name means the 'nearest tarof Centaurus'. It was discovered in 1915 by Robert Innes and is the nearest-kno ...
. The planet, called Proxima Centauri b, could be a potential target for one of the projects of Breakthrough Initiatives.
Breakthrough Starshot
Breakthrough Starshot is a research and engineering project by the Breakthrough Initiatives to develop a Proof of concept, proof-of-concept fleet of light sail interstellar probes named ''Starchip'', to be capable of making the journey to the A ...
is a proof of concept mission to send a fleet of ultra-fast light-driven nanocraft to explore the Alpha Centauri star system, which could pave the way for a first launch within the next generation. An objective of the mission would be to make a fly-by of and possibly photograph any Earth-like worlds that might exist in the system.
In March 2019, ESO astronomers, employing the
GRAVITY instrument on their
Very Large Telescope Interferometer (VLTI), announced the first
direct detection of an
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 ...
,
HR 8799 e
HR 8799 e is a large exoplanet, orbiting the star HR 8799, which lies 129 light-years from Earth. This gas giant is between 5 and 10 times the mass of Jupiter, the largest planet in the Planetary System. Due to their young age and high temperature ...
, using
optical interferometry
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber opti ...
.
Age of the universe
![The Globular Cluster 47 Tu](https://upload.wikimedia.org/wikipedia/commons/e/e7/The_Globular_Cluster_47_Tu.jpg)
With the Very Large Telescope, astronomers have made an independent determination of the age of the universe and shed new light on the earliest stages of the Milky Way. For the first time, they measured the amount of the
radioactive isotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
uranium-238 in a star born when the Milky Way was still forming.
Like
carbon dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.
The method was dev ...
over longer timescales, the uranium clock measures the age of a star. It shows that this star is 12.5 billion years old. Because the star cannot be older than the universe itself, the universe must be older than this. This agrees with known
cosmology
Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount (lexicographer), Thomas Blount's ''Glossographia'', and in 1731 taken up in ...
, which gives an
age of the universe
In physical cosmology, the age of the universe is the time elapsed since the Big Bang. Astronomers have derived two different measurements of the age of the universe:
a measurement based on direct observations of an early state of the universe, ...
of 13.8 billion years. The star (and the Milky Way) must have formed soon after the Big Bang.
Another result is the first measurement of the
beryllium
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form mi ...
content of two stars in a Milky Way
globular cluster
A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of membe ...
. With this measurement, astronomers found that the first generation of stars in our galaxy must have formed soon after the end of the 200-million-year "
Dark Age
The ''Dark Ages'' is a term for the Early Middle Ages, or occasionally the entire Middle Ages, in Western Europe after the fall of the Western Roman Empire that characterises it as marked by economic, intellectual and cultural decline.
The conce ...
" following the Big Bang.
Milky Way black hole
Astronomers long suspected that a black hole exists at the center of the Milky Way, but their theory was unproven. Conclusive evidence was obtained after 16 years of monitoring the
Galactic Center
The Galactic Center or Galactic Centre is the rotational center, the barycenter, of the Milky Way galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a compact rad ...
with ESO telescopes at the La Silla and Paranal observatories.
Stars at the centre of the Milky Way are so densely packed that special imaging techniques (such as
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 ...
) were needed to boost the resolution of the VLT. Thanks to these techniques, astronomers were able to watch individual stars with unprecedented accuracy as they circled the Galactic Center.
Their paths conclusively demonstrated that they were orbiting in the immense gravitational grip of a supermassive black hole nearly three million times more massive than the sun. The VLT observations also revealed flashes of infrared light emerging from the region at regular intervals. While the cause of this phenomenon is unknown, observers have suggested that the black hole may be spinning rapidly.
The VLT has also peered into the centre of galaxies beyond our own, where clear signs of activity produced by supermassive black holes are found. In the
active galaxy
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not prod ...
NGC 1097, a complex network of filaments spiraling from the main part of the galaxy to its centre was seen in great detail.
Gamma-ray bursts
Gamma-ray burst
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milli ...
s (GRBs) are bursts of highly energetic gamma rays lasting from less than one second to several minutes. They are known to occur at great distances from earth, near the limits of the observable universe.
The VLT has observed the afterglow of the farthest known gamma-ray burst. With a measured redshift of 8.2, the light from this very remote astronomical source has taken more than 13 billion years to reach the earth. It occurred when the universe was less than 600 million years old (less than five percent of its present age), and released 300 times as much energy in a few seconds as the sun will in its entire lifetime (more than 10 billion years).
The nature of these explosions has long been a mystery. Observations show that GRBs are one of two types: short- (less than a few seconds) and long-duration. Until 2003, it was suspected that two different types of cosmic event caused them. In 2003, ESO telescopes followed the aftermath of an explosion for one month. Their data showed that the light had similar properties to that of a supernova, and allowed astronomers to link long-duration GRBs with the ultimate explosions of massive stars (
hypernova
A hypernova (sometimes called a collapsar) is a very energetic supernova thought to result from an extreme core-collapse scenario. In this case, a massive star (>30 solar masses) collapses to form a rotating black hole emitting twin energetic je ...
e).
In 2005, ESO telescopes detected visible light after a short-duration burst and tracked this light for three weeks. The conclusion was that short-duration bursts could not be caused by a hypernova; instead, it is thought that they originate in the violent merges of neutron stars or black holes.
Observations of gamma-ray-burst afterglows were coordinated between the VLT and the
Atacama Pathfinder Experiment
The Atacama Pathfinder Experiment (APEX) is a radio telescope 5,064 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert in northern Chile, 50 km east of San Pedro de Atacama built and operated by 3 European r ...
(APEX) to identify the possible counterpart (and its decay) at submillimeter wavelengths.
Digital archives
![Science-archive-data](https://upload.wikimedia.org/wikipedia/commons/1/18/Science-archive-data.jpg)
The Science Archive Operation Group receives and redistributes ESO data and provides archival support. About 200 Terabytes (TB) of public data are distributed per year through the ESO archive. The archive is about 1.01 Petabytes (PB), with an input rate of about 131 TB per year; this is being increased by a factor of 10 or so due to the survey telescopes' data-production rate.
Breakthroughs in telescope, detector and computer technology now allow astronomical surveys to produce large numbers of images, spectra and catalogues. These data sets cover the sky at all wavelengths, from gamma- and X-rays through optical, infrared and radio waves. Astronomers are developing ways to make the large amount of data easily accessible. These techniques use the grid paradigm of distributed computing with seamless, transparent access to data through virtual observatories (VOs). As a physical observatory has telescopes with unique astronomical instruments, a VO consists of data centres with unique collections of astronomical data, software systems and processing capabilities. This global, community-based initiative is being developed under the International Virtual Observatory Alliance and in Europe as part of the EURO-VO project.
VOs have proven their effectiveness in a number of ways, including discovering 31 optically faint, obscured
quasar
A quasar is an extremely Luminosity, luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a m ...
candidates in existing
Great Observatories Origins Deep Survey
The Great Observatories Origins Deep Survey, or GOODS, is an astronomical survey combining deep observations from three of NASA's Great Observatories: the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory, al ...
(GOODS) fields (quadrupling the number previously found). The discovery means that surveys of supermassive black holes have underestimated their numbers by a factor of two to five.
Major discoveries
; Proxima Centauri b, the closest potentially habitable exoplanet
: An ESO team led by Guillem Anglada-Escudé found
Proxima Centauri b
Proxima Centauri b (or Proxima b), sometimes referred to as Alpha Centauri Cb, is an exoplanet orbiting in the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of the triple star system Alpha ...
. The discovery was reported in ''Nature'' on 24 August 2016.
; Stars orbiting Milky Way black hole
: Several of ESO telescopes were used in a 16-year study to obtain the most detailed view to date of the surroundings of the
supermassive black hole at the centre of the galaxy.
; Accelerating universe
: Two independent research teams have shown that the universe's expansion is
accelerating
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by the ...
, based on exploding-star observations with astronomical telescopes at La Silla. The research teams were awarded the 2011
Nobel Prize in Physics
)
, image = Nobel Prize.png
, alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...
for their discovery.
; Oldest known Milky Way star
: Using ESO's VLT, astronomers have measured the age of the
oldest known star in the
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
. At 13.2 billion years, the star was born in the universe's earliest era of star formation.
However, the
oldest star
The age of the oldest known stars approaches the age of the universe, about 13.8 billion years. Some of these are among the first stars from reionization (the stellar dawn), ending the Dark Ages about 370,000 years after Big Bang. Thes ...
seems to be 13.6 billion years old, and the
Methuselah star
HD 140283 (also known as the Methuselah star) is a metal-poor subgiant star about 190 light years away from the Earth in the constellation Libra, near the boundary with Ophiuchus in the Milky Way Galaxy. Its apparent magnitude i ...
might be even older.
; Measuring exoplanet spectra and atmosphere
: The atmosphere around an
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 ...
has been analysed for the first time with the VLT. The planet,
GJ 1214b
Gliese 1214 b (often shortened to GJ 1214 b) is an exoplanet that orbits the star Gliese 1214, and was discovered in December 2009. Its parent star is 48 light-years from the Sun, in the constellation Ophiuchus. As of 2017, GJ 1214 b is the most ...
, was studied as it passed in front of its parent star and
starlight
Starlight is the light emitted by stars. It typically refers to visible electromagnetic radiation from stars other than the Sun, observable from Earth at night, although a component of starlight is observable from Earth during daytime.
Sunligh ...
passed through the planet's atmosphere.
; First image of exoplanet
: The VLT has obtained the
first image of a planet outside the
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
. The 5-Jupiter-mass planet orbits a failed star—a
brown dwarf
Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...
—at a distance of 55 times the mean Earth-Sun distance.
; Rich planetary system
: Astronomers using
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 ...
have discovered a planetary system (with at least five planets) orbiting a sunlike star,
HD 10180
HD 10180, also designated 2MASS J01375356-6030414, is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and ...
. Two other planets may be present, one of which would have the lowest mass ever found.
; Supermassive black hole flares at Milky Way centre
: The VLT and APEX collaborated to study violent flares from the
supermassive black hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical obj ...
at the centre of the Milky Way, revealing material stretched as it orbits in the intense gravitational field near the central black hole.
; Gamma-ray bursts
: ESO telescopes have provided proof that long
gamma-ray bursts
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten millise ...
are linked with the
explosion of massive stars; short gamma-ray bursts seem to be produced by merging
neutron star
A neutron star is the collapsed core of a massive supergiant star, which had a total mass of between 10 and 25 solar masses, possibly more if the star was especially metal-rich. Except for black holes and some hypothetical objects (e.g. white ...
s.
; Milky Way stellar motion
: After more than 1,000 nights of observation at La Silla over a 15-year period, astronomers have determined the motion of more than 14,000 sunlike stars in the vicinity of the sun (demonstrating that the Milky Way is more turbulent and chaotic than previously thought).
; Cosmic-temperature measurements
: The VLT has detected, for the first time, carbon-monoxide molecules in a galaxy located almost 11 billion light-years away. This has allowed astronomers to obtain a precise measurement of cosmic temperature at such a remote location.
Outreach
Outreach activities are carried out by the ESO education and Public Outreach Department (ePOD). These include a range of programs and products that aim to meet the requirements of media, science communicators and the public, such as press releases, images, videos and printed material.
Events such as the 2009 International Year of Astronomy (
IYA2009
The International Year of Astronomy (IYA2009) was a year-long celebration of astronomy that took place in 2009 to coincide with the 400th anniversary of the first recorded astronomical observations with a telescope by Galileo Galilei and the pu ...
) (with
IAU
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
and
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
), VLT First Light, Astronomy Online and the
Comet Shoemaker–Levy 9
Comet Shoemaker–Levy 9 ( formally designated D/1993 F2) broke apart in July 1992 and collided with Jupiter in July 1994, providing the first direct observation of an extraterrestrial collision of Solar System objects. This generated a l ...
impact, have been reported by the Department.
ePOD organises exhibitions and educational campaigns, such as
Venus Transit
frameless, upright=0.5
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a trans ...
,
Science on Stage and Science in School.
ePOD also manages the
ESO Supernova Planetarium & Visitor Centre
The ESO Supernova Planetarium & Visitor Centre is an astronomy centre located at the site of the European Southern Observatory (ESO) Headquarters in Garching bei München. It offers exhibitions, guided tours and planetarium shows that feature o ...
, an astronomy centre located at the site of the ESO Headquarters in Garching bei München, which was inaugurated 26 April 2018.
A collection of photos and videos can be found in the ESO Public Image Gallery and Video Library. Products from educational material to press kits may be downloaded from the ePOD website or ordered in physical form.
As part of the Department, European outreach for the
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
/
ESA
, owners =
, headquarters = Paris, Île-de-France, France
, coordinates =
, spaceport = Guiana Space Centre
, seal = File:ESA emblem seal.png
, seal_size = 130px
, image = Views in the Main Control Room (1205 ...
Hubble Space Telescope provides comprehensive information about the telescope and its scientific discoveries. The International Astronomical Union (IAU) Press Office is also hosted by ePOD.
Publications
The ESO Annual Report details activities across the organisation and outlines scientific, technical and organisational highlights. All issues dating back to the first report in 1964 are available for download.
ESO press releases describe scientific, technical and organisational developments and achievements and results obtained by scientists with ESO facilities. The organisation publishes three types of press releases. Science releases describe results (usually appearing in a peer-reviewed journal) involving data from ESO observatories or staff. Organisational releases cover a range of themes related to ESO operations, including news on current and future observatories, new astronomical instruments and announcements of exhibitions worldwide. ESO also selects its best astronomical images, and presents them publicly in periodic photo releases. All press releases (dating back to 1985) are available online. There are child-friendly versions and press releases translated into the languages of ESO's member countries.
The Messenger is a quarterly journal which has presented ESO's activities to the public since May 1974. All back copies are available for download. ESO also publishes announcements and Pictures of the Week on its website. Announcements are shorter than press releases (typically less than 200 words) highlighting stories and events of interest to the community. Pictures of the Week show beautiful (or interesting) photos from ESO telescopes, and may highlight recent events or archival photos. All former entries are available on the website. ESO also publishes several newsletters aimed at scientists and the general public; these are available upon subscription.
The ESOcast
is a video-podcast series dedicated to reporting news and research from ESO.
In 2013, the
IMAX
IMAX is a proprietary system of high-resolution cameras, film formats, film projectors, and theaters known for having very large screens with a tall aspect ratio (approximately either 1.43:1 or 1.90:1) and steep stadium seating.
Graeme F ...
documentary ''
Hidden Universe 3D
''Hidden Universe 3D'' is a 2013 Australian documentary written and directed by Russell Scott. The film is narrated by Golden Globe winner Miranda Richardson and was released to IMAX 3D theaters in 2013.
Description
This documentary takes a ...
'' was produced in co-operation of Cinema Productions,
Film Victoria
VicScreen, formerly known as Film Victoria, is the Victoria State Government, Victorian Government’s creative and economic screen development agency. They function behind the scenes, supporting professionals, infrastructure, projects and ev ...
,
Swinburne University of Technology
Swinburne University of Technology (often simply called Swinburne) is a public research university based in Melbourne, Australia. It was founded in 1908 as the Eastern Suburbs Technical College by George Swinburne to serve those without access ...
, and the European Southern Observatory.
Video gallery
File: ESO’s 50th Anniversary Gala Event.ogv, alt=Video link, with man at podium in background, ESO's 50th-anniversary event (''Munich Residenz
The Residenz (, ''Residence'') in central Munich is the former royal palace of the Wittelsbach monarchs of Bavaria. The Residenz is the largest city palace in Germany and is today open to visitors for its architecture, room decorations, and displ ...
in Germany, 11 October 2012'')
File: Europe to the Stars bite-size.ogv, alt=Video link, with man using surveying equipment in background., ESO's first 50 years of exploring the southern sky
File:Visit of José Manuel Barroso to the VLT.ogv, José Manuel Barroso
José Manuel Durão Barroso (; born 23 March 1956) is a Portuguese politician and university teacher, currently serving as non-executive chairman of Goldman Sachs International. He previously served as the 11th president of the European Commi ...
visits the ESO in January 2013.
File:ESO and its 50th Anniversary, by ESO Director General, Tim de Zeeuw.ogg, Tim de Zeeuw
Pieter Timotheus "Tim" de Zeeuw (born 12 May 1956 in Sleen) is a Dutch astronomer specializing in the formation, structure and dynamics of galaxies. From 2007 to 2017 he was the director general of European Southern Observatory. He is married to ...
talks on ESO and its 50th Anniversary.
File:Making Way for Construction of the ESO Supernova.ogg, The temporary office buildings at the ESO Headquarters in Garching being dismantled.
File:ESO Timelapse Compilation.ogg, Timelapses of ESO's VLT, ALMA
Alma or ALMA may refer to:
Arts and entertainment
* ''Alma'' (film), a 2009 Spanish short animated film
* ''Alma'' (Oswald de Andrade novel), 1922
* ''Alma'' (Le Clézio novel), 2017
* ''Alma'' (play), a 1996 drama by Joshua Sobol about Alma ...
and La Silla site
Image gallery
These images are from ESO's top-100 list.
File: VISTA’s infrared view of the Orion Nebula.jpg, VISTA's infrared view of the Orion Nebula
File: Helix Nebula.jpg, The Helix Nebula
File: Omega Centauri by ESO.jpg, The Globular Cluster Omega Centauri
File: Guisard - Milky Way.jpg, A 340-million pixel starscape from Paranal
File: NGC 2264 by ESO.jpg, NGC 2264 and the Christmas Tree cluster
File: Centre of the Milky Way.jpg, The Centre of the Milky Way
File: NGC 2467 and Surroundings.jpg, NGC 2467 and Surroundings
File: A reproduction of a composite colour image of the Horsehead Nebula and its immediate surroundings - Eso0202a.jpg, The Horsehead Nebula
File: Messier 78.jpg, Messier 78: a reflection nebula in Orion
File: Eta Carinae Nebula.jpg, The WR 22 and Eta Carinae regions of the Carina Nebula
File: The hidden fires of the Flame Nebula.jpg, The hidden fires of the Flame Nebula
File: Early Morning on Paranal.jpg, Early morning on Paranal
File: The future ALMA array on Chajnantor.jpg, The future ALMA array on Chajnantor (artist's rendering)
File: 360-degree Panorama of the Southern Sky.jpg, Rare 360-degree Panorama of the Southern Sky
File: Lagoon Nebula (ESO).jpg, 370-million-pixel starscape of the Lagoon Nebula
File: ESO - The Milky Way panorama (by).jpg, The Milky Way panorama
File: ESO-The Omega Nebula-phot-25a-09-fullres.jpg, The Omega Nebula
File: ESO Centaurus A LABOCA.jpg, Centaurus A
File: ESO-RCW120-Phot-40-08-fullres.tif, Glowing Stellar Nurseries
File: R Coronae Australis region.jpg, The R Coronae Australis region imaged with the Wide Field Imager at La Silla
See also
References
Bibliography
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External links
Atacama Large Millimeter ArrayAPEX telescopeESOESO Top 100 ImagesWebpage for the ESO telescopes at La Silla ObservatoryParanal ObservatoryJames Bond at Paranal
ESO Media on YoutubeESO Vimeo channel2011 video explaining the current and planned work of ESO
{{coord, 48, 15, 36, N, 11, 40, 16, E, type:landmark, display=title
Astronomical observatories in Chile
Astronomy institutes and departments
Atacama Desert
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International scientific organizations based in Europe
Organisations based in Munich
Organizations established in 1962
Science and technology in Europe
Articles containing video clips
1962 establishments in Chile