The Effelsberg 100-m Radio Telescope is a
radio telescope in the
Ahr Hills
The Ahr HillsElkins, T.H. (1972). ''Germany'' (3rd ed.). London: Chatto & Windus, 1972. . (german: Ahrgebirge or ''Ahreifel'' ) are a range of low mountains and hills up to and long in the Eifel region of Germany, which lie roughly southwest of ...
(part of the
Eifel) in
Bad Münstereifel
Bad Münstereifel () is a historical spa town in the district of Euskirchen, Germany, with about 17,000 inhabitants, situated in the far southwest of the German state of North Rhine-Westphalia. The little town is one of only a few historical to ...
,
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
. For 29 years the Effelsberg Radio Telescope was the largest fully steerable radio telescope on Earth, surpassing the
Lovell Telescope
The Lovell Telescope is a radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. When construction was finished in 1957, the telescope was the largest steerable dish radio telescope in the world at ...
in the UK.
In 2000, it was surpassed by the
Green Bank Observatory
The Green Bank Observatory (previously National Radio Astronomy Observatory, Green Bank) is an astronomical observatory located in the National Radio Quiet Zone in Green Bank, West Virginia, U.S. It is the operator of the Robert C. Byrd Green Ba ...
's
Robert C. Byrd Green Bank Telescope
The Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, US is the world's largest fully steerable radio telescope, surpassing the Effelsberg 100-m Radio Telescope in Germany. The Green Bank site was part of the National Radi ...
in
Green Bank
A green bank (sometimes referred to as green investment bank, clean energy finance authority, or clean energy finance corporation) is a financial institution, typically public or quasi-public, that uses innovative financing techniques and market ...
, US, which has a slightly larger elliptical 100 by 110-metre aperture.
Geography
The telescope is located about 1.3 km northeast of Effelsberg, a southeastern part of the town of
Bad Münstereifel
Bad Münstereifel () is a historical spa town in the district of Euskirchen, Germany, with about 17,000 inhabitants, situated in the far southwest of the German state of North Rhine-Westphalia. The little town is one of only a few historical to ...
in
North Rhine-Westphalia
North Rhine-Westphalia (german: Nordrhein-Westfalen, ; li, Noordrien-Wesfale ; nds, Noordrhien-Westfalen; ksh, Noodrhing-Wäßßfaale), commonly shortened to NRW (), is a state (''Land'') in Western Germany. With more than 18 million inha ...
. It is less than 300 m west of the 398 m high Hünerberg, which is in neighbouring
Rhineland-Palatinate
Rhineland-Palatinate ( , ; german: link=no, Rheinland-Pfalz ; lb, Rheinland-Pfalz ; pfl, Rhoilond-Palz) is a western state of Germany. It covers and has about 4.05 million residents. It is the ninth largest and sixth most populous of the ...
. The boundary is a stream, the Effelsberger Bach, which runs only a few metres east of the telescope. The Effelsberger Bach is 6.5 km long, flowing from the Effelsberger Wald into the Sahrbach, which in turn flows south and into the
Ahr
Ahr () is a river in Germany, a left tributary of the Rhine. Its source is at an elevation of approximately above sea level in Blankenheim in the Eifel, in the cellar of a timber-frame house near the castle of Blankenheim. After it crosses fro ...
river.
A hiking path leads past the telescope; in 2004 part of this was turned into a planet trail with information panels about the
Solar System
The Solar System Capitalization 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 ...
with its
planets. The trail ends at the 39 cm model of the
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
next to the visitor centre.
Radio telescope
The Effelsberg radio telescope is operated by 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-Ru ...
, the
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 comin ...
institute of the
Max-Planck-Gesellschaft
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 ...
. It was constructed from 1968 to 1971 and inaugurated on 1 August 1972. A major technical difficulty in building a radio telescope of 100 m diameter was how to deal with the deformation of the mirror due to gravity when it is rotated to point in a different direction. The mirror must have a precise
parabolic shape to focus the radio waves, but a conventionally-designed dish of this size would "sag" slightly when rotated so the mirror loses its parabolic shape. The Effelsberg telescope uses a novel computer-designed mirror support structure which deforms in such a way that the deformed mirror will always take a parabolic shape. The focus will move during such deformation, and the
feed antenna suspended in front of the mirror is moved slightly by the computer control system as the telescope is rotated to keep it at the focus. Tests after completion of the telescope showed that the intended accuracy of the mirror surface of 1 mm had not only been met, but exceeded significantly.
About 45% of the observing time is available to external astronomers. The Effelsberg 100-m telescope was involved in several surveys, including the one at 408 MHz (73 cm) by Haslam et al.
See also
*
Stockert Radio Telescope __NOTOC__
The Stockert Radio Telescope is a historical radio telescope in the Eifel mountain range in Germany, situated 12 km from the Effelsberg 100-m Radio Telescope.
Radio telescope
Germany's first telescope for radio astronomy, with ...
*
Lovell Telescope
The Lovell Telescope is a radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. When construction was finished in 1957, the telescope was the largest steerable dish radio telescope in the world at ...
– at Jodrell Bank Observatory
References
External links
Official website of the Max Planck Institute for Radio AstronomyDr Norbert Junkes video interview on Astrotalkuk.orgEffelsberg Official Webpage
{{Authority control
Radio telescopes
Low-Frequency Array (LOFAR)
1971 establishments in West Germany
Astronomy in Germany
Buildings and structures in Euskirchen (district)