The Westerbork Synthesis Radio Telescope (WSRT) is an aperture synthesis

Aperture synthesis

Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection...

 interferometer near camp Westerbork

Westerbork (camp)

Westerbork concentration camp was a World War II Nazi refugee, detention and transit camp in Hooghalen, ten kilometres north of Westerbork, in the northeastern Netherlands. Its function during the Second World War was to assemble Roma and Dutch Jews for transport to other Nazi concentration...

, north of the village of Westerbork

Westerbork (village)

Westerbork is a town in the Dutch province of Drenthe. It is a part of the municipality of Midden-Drenthe.The village gives its name to the Westerbork deportation and later, concentration camp, located about 7 km north of the village, in the forests of Hooghalen.The Westerbork Synthesis Radio...

, Midden-Drenthe

Midden-Drenthe

Midden-Drenthe is a municipality in the northeastern Netherlands. The municipality was created in 1998, in a merger of the former municipalities of Beilen, Smilde, and Westerbork...

, in the northeastern Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

. It consists of a linear array of 14 antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

s with a diameter of 25 metres arranged on a 2.7 km East-West line. It has a similar arrangement to other radio telescope

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...

s such as the One-Mile Telescope

One-Mile Telescope

The One-Mile Telescope at the Mullard Radio Astronomy Observatory is an array of radio telescopes designed to perform aperture synthesis interferometry.- History :The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge...

, Australia Telescope Compact Array

Australia Telescope Compact Array

The Australia Telescope Compact Array is a radio telescope at the Paul Wild Observatory, twenty five kilometres west of the town of Narrabri in Australia....

 and the Ryle Telescope

Ryle Telescope

The Ryle Telescope was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004 three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19...

. It's Equatorial mount

Equatorial mount

An equatorial mount is a mount for instruments that follows the rotation of the sky by having one rotational axis parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescopes and cameras...

 is what sets it apart from most other radio telescopes, most of which have an Altazimuth mount

Altazimuth mount

An altazimuth or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two mutually perpendicular axes; one vertical and the other horizontal. Rotation about the vertical axis varies the azimuth of the pointing direction of the instrument...

. This makes it specifically useful for specific types of science, like polarized emission research as the detectors maintain a constant orientation on the sky during an observation. Ten of the telescopes are on fixed mountings while the remaining four dishes are movable along two rail tracks

Rail tracks

The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...

. The telescope was completed in 1970 and underwent a major upgrade between 1995-2000.

The telescopes in the array can operate at several frequencies between 120 MHz and 8.3 GHz

GHZ

GHZ or GHz may refer to:# Gigahertz .# Greenberger-Horne-Zeilinger state — a quantum entanglement of three particles.# Galactic Habitable Zone — the region of a galaxy that is favorable to the formation of life....

 with an instantaneous bandwidth of 120 MHz and 8092 line spectral resolution. The WSRT is often combined with other telescopes around the world to perform Very Long Baseline Interferometry

Very Long Baseline Interferometry

Very Long Baseline Interferometry is a type of astronomical interferometry used in radio astronomy. It allows observations of an object that are made simultaneously by many telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.Data...

 (VLBI) observations, being part of the European VLBI Network

European VLBI Network

The European VLBI Network was formed in 1980 by a consortium of five of the major radio astronomy institutes in Europe . Since 1980, the EVN and the Consortium has grown to include 9 institutes with 12 radio telescopes in 8 western European countries as well as associated institutes with...

. The telescope is operated by ASTRON

ASTRON

ASTRON is the Netherlands Foundation for Research in Astronomy. ASTRON is an abbreviation of the Dutch Stichting ASTRonomisch Onderzoek in Nederland. This translates to NFRA in English, which is sometimes used to refer to ASTRON in English texts. Its main offices are in Dwingeloo at the site of the...

, the Dutch foundation for astronomy research.

The WSRT is scheduled for another upgrade around 2013 as part of the APERTIF project where the current detectors will be replaced with Focal Plane Arrays

Focal Plane Arrays

Focal Plane Arrays are arrays of receivers placed at the focus of a radio-telescope. Traditional radio-telescopes have only one receiver at the focus of the telescope, but radio-telescopes are now starting to be equipped with focal plane arrays, which are of three different types: multi-beam feed...

. This will allow a 25x larger field of view and will be used for large scale surveys of the northern sky, bringing back focus on the Hydrogen line

Hydrogen line

The hydrogen line, 21 centimeter line or HI line refers to the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms. This electromagnetic radiation is at the precise frequency of 1420.40575177 MHz, which is equivalent to the vacuum...

 for which it was originally designed, but also large pulsar

Pulsar

A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...

searches and other science.

External links

• SINGS - Spitzer Infrared Nearby Galaxies Survey, done with WSRT.