Mullard Radio Astronomy Observatory

The Mullard Radio Astronomy Observatory (MRAO) is located near Cambridge, UK and is home to a number of the largest and most advanced aperture synthesis radio telescopes in the world, including the One-Mile Telescope, 5-km Ryle Telescope, and the Arcminute Microkelvin Imager. It was founded by the University of Cambridge and is an institute of the Cambridge University Astronomy Department.

Mullard Radio Astronomy Observatory

Named after	Mullard
Location	United Kingdom
Coordinates	52°10′03″N 0°01′57″E
Telescopes	4C Array Arcminute Microkelvin Imager Cambridge Low Frequency Synthesis Telescope Cambridge Optical Aperture Synthesis Telescope Half-Mile Telescope Interplanetary Scintillation Array One-Mile Telescope Ryle Telescope
Location of Mullard Radio Astronomy Observatory
Related media on Wikimedia Commons

One antenna of the One-Mile Telescope at the observatory

History

Radio interferometry started in the mid-1940s on the outskirts of Cambridge, but with funding from the Science Research Council and a corporate donation of £100,000 from Mullard Limited, a leading commercial manufacturer of thermionic valves.

Construction of the Mullard Radio Astronomy Observatory commenced at Lords Bridge,[1] a few kilometres to the west of Cambridge.

The observatory was founded under Martin Ryle of the Radio-Astronomy Group of the Cavendish Laboratory, University of Cambridge and was opened by Sir Edward Victor Appleton on 25 July 1957. This group is now known as the Cavendish Astrophysics Group.

Location

The site is located a few miles south-west of Cambridge University at Lords Bridge Station in Greater Cambridgeshire on a former ordnance storage facility, next to the now-disused Oxford-Cambridge Varsity railway line.

A portion of the track bed of the old line, running nearly east-west for several miles, was used to form the main part of the "5km" radio-telescope and the Cambridge Low Frequency Synthesis Telescope.

Telescopes

Telescope	Year built	Status
Arcminute Microkelvin Imager Large Array	2007	Active
Arcminute Microkelvin Imager Small Array	2004	Active
Very Small Array (moved to Tenerife in 1999)	1998	Active
Cosmic Anisotropy Telescope made first high-resolution maps of Cosmic Microwave Background fluctuations	1995	Decommissioned
Cambridge Optical Aperture Synthesis Telescope (COAST) first aperture synthesis at optical wavelengths	1993	Operated on clear nights
One receiver from the e-MERLIN array	1990	Active
Cambridge Low Frequency Synthesis Telescope (CLFST)	1980	Decommissioned
Ryle Telescope (formerly 5-Kilometre Telescope)	1971	Decommissioned (repurposed for AMI LA in 2006)
Half-Mile Telescope	1968	Decommissioned
Interplanetary Scintillation Array discovered first pulsar	1967	Decommissioned
One-Mile Telescope	1964	Decommissioned
4C Array, first telescope at the Cambridge's new observatory, used to make the 4C catalogue	1958	Decommissioned

Gallery

The following photographs (except for the last 2 items) were taken in June 2014:

• 
  Lecture hall and exhibition centre in the station house of Lord's Bridge Railway Station
• 
  Several antennas of the Arcminute Microkelvin Imager Large Array
• 
  The Arcminute Microkelvin Imager Small Array
• 
  Stitched panorama of the Cosmic Anisotropy Telescope enclosure
• 
  Part of the Cambridge Optical Aperture Synthesis Telescope
• 
  The interior of the bunker of the Cambridge Optical Aperture Synthesis Telescope
• 
  The receiver from the e-MERLIN array
• 
  Surviving Yagi antennas of the Cambridge Low Frequency Synthesis Telescope
• 
  Two antennas of the Half-Mile Telescope
• 
  Remains of the Interplanetary Scintillation Array
• 
  One antenna of the One-Mile Telescope (left), two of the Half-Mile Telescope (centre) and the remains of the 4C Array (right)
• 
  Detail of the remains of the 4C Array, with antennas of the One-Mile Telescope in the background
• 
  Mullard EL34 Power Pentode. Mullard produced up to 40% of thermionic valves used by Britain during 1939-1945 War
• 
  The Mullard Foundation plaque

References

Notes

1. "Subterranea Britannica - Lords Bridge".

Sources

• The Mullard Radio Astronomy Observatory webpage
• Image from Google maps showing the One-Mile, Half Mile, 4C Array, MERLIN, COAST, CAT and Ryle telescopes.
• Subterranea Britannica entry for Lords Bridge Forward Filling Depot (also Air Ammunition Park)
• Subterranea Britannica entry for Lords Bridge Station