European Southern Observatory

from Wikipedia, the free encyclopedia
European Southern Observatory ESO
founding 1962
Headquarters Garching, Germany
Observatories Paranal

La Silla

budget € 143 million
General Director Xavier Barcons
Employee 730
Web presence

The European Organization for Astronomical Research in the Southern Hemisphere ( English European Organization for Astronomical Research in the Southern Hemisphere ) or in the short form European Southern Observatory (Engl. European Southern Observatory , ESO ) is a European research institute telescopes in Chile operates.


The many observation facilities of ESO helped astronomy to make numerous discoveries and produced some astronomical catalogs .

Among other things, the most distant gamma-ray burst was observed at ESO observatories , and evidence of the existence of a black hole in the center of our Milky Way was found.

The increase in the rate of expansion of the universe could be shown based on observations of distant supernovae with the telescopes on La Silla.

The Very Large Telescope (VLT, German very large telescope ) was able to analyze carbon monoxide molecules in a galaxy at a distance of around eleven billion light years for the first time . This made it possible to obtain the most precise measurements of temperature for such a distant epoch.

With the VLT, astronomers were also able to determine the greatest measured age of a star in our Milky Way. At 13.2 billion years old, the star was born in one of the earliest phases of star formation in the universe.

In 2004 the first image of an extrasolar planet ( 2M1207 b ) was taken with the help of the VLT . Since then, the HARPS spectrograph has been able to detect many more extrasolar planets.

After a total of more than 1000 nights of observation on La Silla, which extended over 15 years, the movement patterns of more than 14,000 sun-like stars in the vicinity of the sun could be determined. It could thus be shown that our home galaxy went through a more turbulent and chaotic life than was previously assumed.


The Chilean Atacama Desert has excellent climatic conditions for astronomical observations, especially a dry atmosphere and low air currents. For this reason, ESO chose the locations of its facilities here:

The headquarters of ESO with administration and development is located in Garching near Munich .

Installed telescopes and instruments

The ESO's currently best-known telescope is the Very Large Telescope at the Paranal Observatory, which consists of four " Unit Telescopes " with primary mirror diameters of 8.2 m. Four additional auxiliary telescopes with a mirror diameter of 1.8 m were specially developed for interferometry . They form an important part of the VLTI ( VLT Interferometer ), with which several telescopes can be interconnected in order to achieve even more precise observation results.

In addition, there are three telescopes at the La Silla Observatory with main mirror diameters from 1 m to 3.6 m. The Swiss 1.2 m Euler telescope , which is mostly used to search for exoplanets , is also located here.

The Atacama Pathfinder Experiment (APEX) and the Atacama Large Millimeter Array (ALMA) are currently installed on the 5000 m high level of the Llano de Chajnantor .

ESO telescopes
Surname size Type Location
Very Large Telescope (VLT) 4 × 8.2 m + 4 × 1.8 m Interconnectable optical, near infrared and mid infrared telescopes Paranal
New Technology Telescope (NTT) 3.58 m optical and infrared telescope La Silla
ESO 3.6 m telescope 3.57 m optical and infrared telescope La Silla
MPG / ESO 2.2 m telescope 2.20 m optical and infrared telescope La Silla
Atacama Pathfinder Experiment (APEX) 12 m Millimeter / sub-millimeter wavelength telescope Chajnantor
Atacama Large Millimeter Array (ALMA) 50 × 12 m and 12 × 7 m + 4 × 12 m (ACA) Interconnectable millimeter / submillimeter wavelength telescopes Chajnantor
Visible and Infrared Survey Telescope for Astronomy (VISTA) 4.1 m Near-Infrared Surveying Telescope Paranal
VLT Survey Telescope (VST) 2.6 m optical survey telescope Paranal
Extremely Large Telescope (ELT) 39.3 m optical, near and mid-infrared telescope Armazones

Future telescopes and instruments

A study on the 39 m ELT, on the right for a size comparison the protective cover of one of the telescopes of the VLT

For the future, ESO is already planning a 30 m to 60 m reflecting telescope with the working title Extremely Large Telescope (ELT). The preferred planning variant is based on a 39 m mirror with adaptive optics, which is supposed to offer a hundred times the sensitivity compared to the telescopes of the VLT. On April 26, 2010 the Cerro Armazones , a mountain with a height of 3060 m, was fixed as the location for the E-ELT. Cerro Armazones is located in the Chilean Atacama Desert , approx. 130 km south of the city of Antofagasta and only 20 km away from Cerro Paranal, the location of the Very Large Telescope (VLT). On December 9, 2011, the starting shot for the construction of the telescope in the Chilean Atacama Desert was fired, although not all 15 member states of the European Southern Observatory had secured the additional financing requirements for the device. The costs are put at 1.1 billion euros at the end of 2011.

Previously an even larger telescope project called the Overwhelmingly Large Telescope (OWL) had been studied. However, the plans for the OWL had been postponed for the time being in favor of the E-ELT due to the complexity and high costs.

On December 20, 2018, ESO announced that the “Cherenkov Telescope Array South” would be built at its Paranal site and operated by ESO. The Cherenkov Telescope Array (CTA) will be the world's largest gamma-ray observatory, with one location each in the northern and southern hemispheres. The northern array will be built on the island of La Palma , Spain.


The ESO headquarters in Garching 1997 Headquarters with new expansion in 2016
The ESO headquarters in Garching 1997
Headquarters with new expansion in 2016

The organization was founded in 1962 to provide European astronomers with the ability to observe the southern sky . In 1980 ESO moved from its former headquarters in Geneva to Garching near Munich . The current building is a gift from the Federal Republic of Germany. Like CERN , for example, as an international institute, ESO is not subject to national jurisprudence, but has quasi- diplomatic status. There are also stations in Chile , an office complex in Santiago , the size and structure of which corresponds to an astronomical institute, and two small regional offices in Antofagasta and La Serena . Then there are the observatories described above . In 2010 the EVALSO project implemented the connection via fiber optic cable .

Member States

Member states accession
Map of the Member States
BelgiumBelgium Belgium 1962
GermanyGermany Germany 1962
FranceFrance France 1962
NetherlandsNetherlands Netherlands 1962
SwedenSweden Sweden 1962
DenmarkDenmark Denmark 1967
ItalyItaly Italy 1982
SwitzerlandSwitzerland Switzerland 1982
PortugalPortugal Portugal 2001
United KingdomUnited Kingdom United Kingdom 2002
FinlandFinland Finland 2004
SpainSpain Spain 2006
Czech RepublicCzech Republic Czech Republic 2007
AustriaAustria Austria 2008
PolandPoland Poland 2014
IrelandIreland Ireland 2018

The ESO has 16 member states. The host nation of the observatories, Chile, is not a member, but astronomers there also have privileged access to the observation time. Astronomers of other nations will only be allowed observation time if they can prove that they have no other adequate means of observation.

On December 29, 2010, Brazil signed a formal declaration of membership of the ESO. Brazil would have become 15th and the first non-European member. However, formal ratification did not take place until 2018 due to a change of government in Brazil and non-compliance with financial commitments of € 270 million for a period of 10 years, and access to the ESO was then temporarily suspended on March 12, 2018.

On October 28, 2014, Professor Lena Kolarska-Bobińska , Polish Minister for Science and Higher Education, and Tim de Zeeuw, Director General of ESO, in the presence of high-ranking representatives of ESO and the Republic of Poland, signed an agreement in Warsaw according to which the Republic of Poland is part of the international community intends to join. It was ratified on July 8, 2015, making Poland the 15th member state of the ESO.

On July 11, 2017, Australia became a strategic partner with the prospect of full membership within 10 years. Australian researchers can access the ESO facilities during this period in return for a financial contribution to the ESO budget.

Ireland became the 16th member country to join on September 26, 2018.

Technical organization

Observation time can be requested twice a year for the observation semester after the next. Depending on the telescope, two to five times as much time is requested as can actually be allocated. The proposals are weighted by an advisory body according to scientific quality . The data that have been observed for a specific observation project are only accessible to the head of the project during the first twelve months after the observation date ( proprietary period ). After this period, all raw data obtained with ESO telescopes will be freely accessible to everyone via the scientific archive.

The internal employees of ESO receive a tax-exempt income, which is intended, in particular, to make it easier for qualified staff from the member states to work abroad for longer periods. As a rule, employees receive a three-year contract that can be extended if the performance is appropriate. The directorate decides on the conversion into an open-ended contract. For scientists, the ESO offers special annual contracts that are only designed for temporary work.

In addition, the ESO also employs external employees who are subject to the regular taxation of the host country Germany .

Directors General of ESO
Surname Period
Otto Heckmann 1962-1969
Adriaan Blaauw 1970-1974
Lodewijk Woltjer 1975-1987
Harry van der Laan 1988-1992
Riccardo Giacconi 1993-1999
Catherine Cesarsky 1999-2007
Tim de Zeeuw 2007-2017
Xavier Barcons from 2017

See also

Web links

Commons : European Southern Observatory  - collection of images, videos and audio files

Individual evidence

  1. a b About ESO The ESO: Facts and Figures
  2. ^ Distant Supernovae Indicate Ever-Expanding Universe , ESO. December 15, 1998. Retrieved April 5, 2011. 
  3. ^ A Molecular Thermometer for the Distant Universe , ESO. May 13, 2008. Retrieved April 5, 2011. 
  4. How Old is the Milky Way? , ESO. August 17, 2004. Retrieved April 5, 2011. 
  5. Milky Way Past Was More Turbulent Than Previously Known , ESO. April 6, 2004. Retrieved April 5, 2011. 
  6. Telescopes and Instruments . Retrieved April 29, 2011.
  7. Satoru Iguchi et al. : The Atacama Compact Array (ACA) . In: Publ. Astron. Soc. Japan . 61, 2009, pp. 1-12. bibcode : 2009PASJ ... 61 .... 1I . Retrieved April 29, 2011.
  8. ^ The E-ELT project . Retrieved April 29, 2011.
  9. ^ E-ELT Site Chosen - World's Biggest Eye on the Sky to be Located on Armazones, Chile. ESO, April 26, 2010, accessed August 26, 2016 .
  10. ^ Daniel Clery: Europe's Extremely Large Telescope on Its Way. In: December 10, 2011, accessed August 26, 2016 .
  11. ESO: ESO is home to Cherenkov Telescope Array South on Paranal. December 20, 2018, accessed December 20, 2018 .
  12. ^ Agreement on the establishment of a European organization for astronomical research in the southern hemisphere
  13. Stefan Deiters: ESO: Austria is the 14th ESO member country. In: July 1, 2008, accessed August 26, 2016 .
  14. Poland will join the European Southern Observatory. ESO, October 28, 2014, accessed August 26, 2016 .
  15. Brazil becomes a member of the European Southern Observatory
  16. astronomy Ousted from ESO, Brazilian wants to be 'strangled,' says president of the Brazilian Astronomical Society
  17. ^ ESO: Poland ratifies ESO membership. August 15, 2015, accessed December 5, 2018 .
  18. Australia Enters Strategic Partnership with ESO
  19. Ireland joins the European Southern Observatory - Ireland signs agreement to join ESO as the 16th member state. September 26, 2018, accessed December 5, 2018 .
  20. ESO Science Archive