Telescopes and Instrumentation
As set out in its convention, ESO provides state of the art facilities for Europe's astronomers and promotes and organises cooperation in astronomical research. Today, ESO operates some of the world's largest and most advanced observational facilities at three sites in Northern Chile: La Silla, Paranal and Chajnantor. These are the best locations known in the southern hemisphere for astronomical observations. With other activities such as technology development, conferences and educational projects, ESO also plays a decisive role in forming a European Research Area for astronomy and astrophysics.
The Very Large Telescope (VLT) at Cerro Paranal is ESO's premier site for observations in the visible and infrared light. All four unit telescopes of 8.2m diameter are individually in operation with a large collection of instruments.
The VLT offers also the possibility of combining the light from the four UTs to work as an interferometer. The Very Large Telescope Interferometer (VLTI), with its own suite of instruments, ultimately providing imagery at the milli-arcsecond level as well as astrometry at 10 micro arcsecond precision. In addition to the 8.2m diameter telescopes the VLTI is complemented with four Auxiliary Telescopes (AT) of 1.8m diameter to improve its imaging capabilities and enable full nighttime use on a year-round basis.
Two telescopes for imaging surveys are also in operation at Paranal, the VLT Survey Telescope (VST, 2.6-metre diameter) for the visible, and the Visible and Infrared Survey Telescope for Astronomy (VISTA, 4.1-metre) for the infrared.
La Silla Observatory
ESO operates three major telescopes (3.6m telescope, New Technology Telescope (NTT), 2.2m Max-Planck-ESO telescope) at the La Silla Observatory. They are equipped with state of the art instruments either built completely by ESO or by external consortia, with substantial contribution by ESO.
APEX, the Atacama Pathfinder Experiment, is a collaboration between Max Planck Institut für Radioastronomie (MPIfR) at 50%, Onsala Space Observatory (OSO) at 23%, and the European Southern Observatory (ESO) at 27% to construct and operate a modified ALMA prototype antenna as a single dish on the 5100 m high site of Llano Chajnantor. The telescope was supplied by VERTEX Antennentechnik in Duisburg, Germany. APEX has a suite of heterodyne spectrometers and wide-field bolometer cameras operating in most of the atmospheric windows from 0.2 to 1.4 mm. The telescope is operated by ESO.
The Atacama Large Millimeter/submillimeter Array, or ALMA, is an international collaboration to develop a telescope of revolutionary design to study the universe from a site in the foothills of Chile's Andes Mountains. ALMA will be composed initially of 66 high precision antennas, operating at wavelengths of 0.32 to 3.6 mm. Its main 12-metre array will have fifty antennas, each 12 metres in diameter, acting together as a single telescope — an interferometer. An additional compact array of four 12-metre and twelve 7-metre antennas will complement this. The ALMA antennas can be arranged in different configurations, where the maximum distance between antennas can vary from 150 metres to 16 kilometres, which will give ALMA a powerful variable "zoom". The ALMA correlator, a specialised computer that combines the information received by the antennas, will perform an astounding 16,000 million-million (1.6x1016) operations per second.
ALMA's construction will be completed in 2013, but early scientific observations with a partial array will begin in 2011. The ALMA Project is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA.
ESO has been working together with its user community of European astronomers and astrophysicists to define the new giant telescope needed by the middle of the next decade. More than one hundred astronomers from all European countries have been involved throughout 2006, helping the ESO Project Offices to produce a novel concept, in which performance, cost, schedule and risk were carefully evaluated.
The present concept features as a baseline a telescope with a 40-metre-class main mirror, and is revolutionary. The site of the E-ELT will be Cerro Armazones, 20 km from Paranal, site of the VLT.
With a 40-metre-class primary mirror and its adaptive optics concept, the E-ELT may revolutionise our perception of the Universe, much as Galileo's telescope did, 400 years ago, when he first pointed a telescope to the sky.
For more information please read the E-ELT page.