Effelsberg
Encyclopedia
The Effelsberg 100-m Radio Telescope is a radio telescope
in the Ahrgebirge (part of the Eifel
) in Bad Münstereifel
, district of Euskirchen
, North Rhine-Westphalia
, Germany
.
. It is placed less than 300 m west of the 398 m high Hünerberg, which is already in the neighbouring Land of Rhineland-Palatinate
.
In the vicinity of the telescope, the boundary of the Land of North Rhine-Westphalia is 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
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
with its planets. The trail ends at the 39 cm model of the Sun
next to the visitor centre.
in Bonn
. 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 as the – supposedly parabolic – mirror moves and tilts. The Finite element method
was used to construct the mirror support in such a way that the deformed mirror will always take a parabolic shape. The focus will move during such deformation, and the receiver has to be moved accordingly. 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. For 29 years the Effelsberg Radio Telescope was the largest fully steerable radio telescope on Earth
. In 2000 it was surpassed by the Robert C. Byrd Green Bank Telescope
in Green Bank, West Virginia
with an elliptical 100 by 110-metre aperture.
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
in the Ahrgebirge (part of the Eifel
Eifel
The Eifel is a low mountain range in western Germany and eastern Belgium. It occupies parts of southwestern North Rhine-Westphalia, northwestern Rhineland-Palatinate and the south of the German-speaking Community of Belgium....
) in Bad Münstereifel
Bad Münstereifel
Bad Münstereifel is a historical spa town in the district of Euskirchen, Germany, with about 19,000 inhabitants, situated in the far south of the German state of North Rhine-Westphalia...
, district of Euskirchen
Euskirchen (district)
Euskirchen is a Kreis in the south-west of North Rhine-Westphalia, Germany. Neighboring districts are Aachen, Düren, Rhein-Erft-Kreis, Rhein-Sieg, Ahrweiler, Daun, Bitburg-Prüm, and the Liège province .-History:...
, North Rhine-Westphalia
North Rhine-Westphalia
North Rhine-Westphalia is the most populous state of Germany, with four of the country's ten largest cities. The state was formed in 1946 as a merger of the northern Rhineland and Westphalia, both formerly part of Prussia. Its capital is Düsseldorf. The state is currently run by a coalition of the...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
.
Geography
The telescope is located about 1.3 km northeast of the village of Effelsberg, a southeastern part of the town of Bad MünstereifelBad Münstereifel
Bad Münstereifel is a historical spa town in the district of Euskirchen, Germany, with about 19,000 inhabitants, situated in the far south of the German state of North Rhine-Westphalia...
. It is placed less than 300 m west of the 398 m high Hünerberg, which is already in the neighbouring Land of Rhineland-Palatinate
Rhineland-Palatinate
Rhineland-Palatinate is one of the 16 states of the Federal Republic of Germany. It has an area of and about four million inhabitants. The capital is Mainz. English speakers also commonly refer to the state by its German name, Rheinland-Pfalz ....
.
In the vicinity of the telescope, the boundary of the Land of North Rhine-Westphalia is 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
Ahr is a river in Germany, a left tributary of the Rhine. Its source is at an elevation of approximately 470 metres above sea level in Blankenheim in the Eifel, in the cellar of a timber-frame house near the castle of Blankenheim...
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
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
with its planets. The trail ends at the 39 cm model of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
next to the visitor centre.
Radio telescope
The Effelsberg radio telescope is operated by the Max Planck Institute for Radio AstronomyMax Planck Institute for Radio Astronomy
The Max Planck Institute for Radio Astronomy is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society .-History:...
in Bonn
Bonn
Bonn is the 19th largest city in Germany. Located in the Cologne/Bonn Region, about 25 kilometres south of Cologne on the river Rhine in the State of North Rhine-Westphalia, it was the capital of West Germany from 1949 to 1990 and the official seat of government of united Germany from 1990 to 1999....
. 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 as the – supposedly parabolic – mirror moves and tilts. The Finite element method
Finite element method
The finite element method is a numerical technique for finding approximate solutions of partial differential equations as well as integral equations...
was used to construct the mirror support in such a way that the deformed mirror will always take a parabolic shape. The focus will move during such deformation, and the receiver has to be moved accordingly. 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. For 29 years the Effelsberg Radio Telescope was the largest fully steerable radio telescope on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. In 2000 it was surpassed by the Robert C. Byrd Green Bank Telescope
Green Bank Telescope
The Robert C. Byrd Green Bank Telescope is the world's largest fully steerable radio telescope and the world's largest land-based movable structure. It is part of the National Radio Astronomy Observatory site at Green Bank, West Virginia, USA. The telescope honors the name of the late Senator...
in Green Bank, West Virginia
Green Bank, West Virginia
Green Bank is a census-designated place in Pocahontas County in West Virginia's Potomac Highlands inside the Allegheny Mountain Range. Green Bank is located along WV 28. Green Bank is also close to the Snowshoe Mountain ski resort...
with an elliptical 100 by 110-metre aperture.
| Reflector Diameter | 100 m |
| Aperture | 7,854 m2 |
| Number of Surface Elements (Panels) | 2,352 |
| Shape Accuracy of Surface | < 0.5 mm |
| Focal Length in Prime Focus | 30 m |
| Secondary Mirror Diameter (Gregory-Reflector) | 6.5 m |
| Aperture Stop | |
| – in Prime Focus | f/0.3 |
| – in Secondary Focus | f/3.85 |
| Angular Resolution (Beam Width) | |
| – at 21 cm wavelength (1.4 GHz) | 9.4' (arc minutes) |
| – at 3 cm wavelength (10 GHz) | 1.15' (arc minutes) |
| – at 3.5 mm wavelength (86 GHz) | 10" (arc seconds) |
| Azimuth Track Diameter | 64 m |
| Setting Accuracy of Track | ±0.25 mm |
| Azimuth Range | 480° |
| Maximum Rotation Speed | 30°/min. |
| Pointing Accuracy | |
| – Blind Pointing | 10" |
| – Repeatability | 2" |
| Power Output of the 16 Azimuth Drives | 10.2 kW each |
| Radius of Elevation Gear Track | 28 m |
| Elevation Range | from 7° to 94° |
| – during observations | from 8.1° to 89° |
| Maximum Tilt Speed | 16°/min. |
| Power Output of the 4 Elevation Drives | 17.5 kW each |
| Total Weight | 3,200 t |
| Construction Period | 1968–1971 |
| Height of Track above Sea Level | 319 m |
| Commencement of Operation | 1 August 1972 |
| Constructed by | Arbeitsgemeinschaft KRUPP/MAN |
See also
- Radio astronomyRadio astronomyRadio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
- Radio telescopeRadio telescopeA radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
- Stockert Radio TelescopeStockert Radio TelescopeThe Stockert Radio Telescope is a historical radio telescope on a 435 m high hill in Bad Münstereifel, west of Bonn, Germany.- Geography :...
- Lovell TelescopeLovell TelescopeThe Lovell Telescope is a radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. When it was constructed in 1955, the telescope was the largest steerable dish radio telescope in the world at 76.2 m in diameter;it is now the third largest, after the...
at Jodrell Bank Observatory
External links
- Dr Norbert Junkes video interview on Astrotalkuk.org
- Effelsberg Official Webpage
- Page at Max-Planck-Gesellschaft institute
- Bill Keel's "Telescopes I've seen"