Sixth Cambridge Survey of Radio Sources

Last updated
Sixth Cambridge Survey of radio sources
Alternative names6C
Survey type astronomical survey   OOjs UI icon edit-ltr-progressive.svg
Organization Cavendish Astrophysics Group   OOjs UI icon edit-ltr-progressive.svg
Observations Cambridge Low Frequency Synthesis Telescope   OOjs UI icon edit-ltr-progressive.svg
Frequency 151 megahertz  OOjs UI icon edit-ltr-progressive.svg

The 6C Survey of Radio Sources (6C) is an astronomical catalogue of celestial radio sources as measured at 151-MHz. [1] [2] It was published between 1985 and 1993 by the Radio Astronomy Group of the University of Cambridge. [3] [4] [5] [6] [7] [8] [9]

The research that led to the catalogue's production also led to improvements in radio telescope design and, in due course, to the 7C survey of radio sources. [1]

A similar survey of the Southern Hemisphere was made by the Mauritius Radio Telescope. [10] [11]

Related Research Articles

Amateur astronomy Hobby of watching the sky and stars

Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxies.

Microscopium Minor constellation in the southern celestial hemisphere

Microscopium is a minor constellation in the southern celestial hemisphere, one of twelve created in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. The name is a Latinised form of the Greek word for microscope. Its stars are faint and hardly visible from most of the non-tropical Northern Hemisphere.

Radio telescope form of directional radio antenna used in radio astronomy

A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects. Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.

Astronomy Scientific study of celestial objects and phenomena

Astronomy is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates outside Earth's atmosphere. Cosmology is a branch of astronomy. It studies the Universe as a whole.

Radio astronomy subfield of astronomy that studies celestial objects at radio frequencies

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 1932, when Karl Jansky at Bell Telephone Laboratories observed radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers. The discovery of the cosmic microwave background radiation, regarded as evidence for the Big Bang theory, was made through radio astronomy.

Astrophysics is the branch of astronomy that employs the principles of physics and chemistry "to ascertain the nature of the astronomical objects, rather than their positions or motions in space". Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.

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. At each separation and orientation, the lobe-pattern of the interferometer produces an output which is one component of the Fourier transform of the spatial distribution of the brightness of the observed object. The image of the source is produced from these measurements. Astronomical interferometers are commonly used for high-resolution optical, infrared, submillimetre and radio astronomy observations. For example, the Event Horizon Telescope project derived the first image of a black hole using aperture synthesis.

Giant Metrewave Radio Telescope radio telescope

The Giant Metrewave Radio Telescope (GMRT) Observatory, located near Pune, Junnar, Narayangaon in India, is an array of thirty fully steerable parabolic radio telescopes of 45 metre diameter, observing at metre wavelengths. It is operated by the National Centre for Radio Astrophysics (NCRA), a part of the Tata Institute of Fundamental Research, Mumbai. It was conceived and built under the direction of Late Prof. Govind Swarup during 1984 to 1996. At the time it was built, it was the world's largest interferometric array offering a baseline of up to 25 kilometres (16 mi).

Messier 84 Elliptical or lenticular galaxy in the constellation Virgo

Messier 84 or M84, also known as NGC 4374, is an elliptical or lenticular galaxy in the constellation Virgo. Charles Messier discovered Messier 84 on 18 March 1781 in a systematic search for "nebulous objects" in the night sky. The object is the 84th in the Messier Catalogue. M84 is situated in the heavily populated inner core of the Virgo Cluster of galaxies.

The Third Cambridge Catalogue of Radio Sources (3C) is an astronomical catalogue of celestial radio sources detected originally at 159 MHz, and subsequently at 178 MHz.

The Cavendish Astrophysics Group is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank.

Molonglo Observatory Synthesis Telescope

The Molonglo Observatory Synthesis Telescope (MOST) is a radio telescope operating at 843 MHz. It is operated by the School of Physics of the University of Sydney. The telescope is located in Hoskinstown, near the Molonglo River and Canberra, and was constructed by modification of the East-West arm of the former Molonglo Cross Telescope, a larger version of the Mills Cross Telescope.

The 5C Survey of Radio Sources (5C) is an astronomical catalogue of celestial radio sources as measured at 408 MHz and 1407 MHz. It was published in a number of parts between 1975 and 1995 by the Radio Astronomy Group of the University of Cambridge. The One-Mile Telescope used to produce this catalogue had an angular resolutions of 80 arcseconds and 23 arcseconds at 408 MHz and 1407 MHz respectively, and catalogued radio sources as faint as 2 milli-Janskys, considerably fainter than any previously catalogued radio source.

Cambridge Low Frequency Synthesis Telescope

The Cambridge Low-Frequency Synthesis Telescope (CLFST) is an east-west aperture synthesis radio telescope currently operating at 151 MHz. It consists of 60 tracking yagis on a 4.6 km baseline, giving 776 simultaneous baselines. These provide a resolution of 70×70 cosec (declination) arcsec2, with a sensitivity of about 30 to 50 mJy/beam, and a field of view of about 9°×9°. The telescope is situated at the Mullard Radio Astronomy Observatory.

Mauritius Radio Telescope

The Mauritius Radio Telescope (MRT) is a synthesis radio telescope in Mauritius that is used to make images of the sky at a frequency of 151.5 MHz. The MRT was primarily designed to make a survey with a point source sensitivity of 150 mJy. Its resolution is about 4 arc min.

Allen Telescope Array A radio telescope array

The Allen Telescope Array (ATA), formerly known as the One Hectare Telescope (1hT), is a radio telescope array dedicated to astronomical observations and a simultaneous search for extraterrestrial intelligence (SETI). The array is situated at the Hat Creek Radio Observatory in Shasta County, 290 miles (470 km) northeast of San Francisco, California.

Ooty Radio Telescope

The Ooty Radio Telescope (ORT) is located in Muthorai near Ooty, in southern India. It is part of the National Centre for Radio Astrophysics (NCRA) of the Tata Institute of Fundamental Research (TIFR), which is funded by the Government of India through the Department of Atomic Energy. The radio telescope is a 530-metre (1,740 ft) long and 30-metre (98 ft) tall cylindrical parabolic antenna. It operates at a frequency of 326.5 MHz with a maximum bandwidth of 15 MHz at the front end.

Delta1 Chamaeleontis, Latinized from δ1 Chamaeleontis, is a close double star located in the constellation Chamaeleon. It has a combined apparent visual magnitude of 5.47, which is just bright enough for the star to be faintly seen on a dark rural night. With an annual parallax shift of 9.36 mas, it is located around 350 light years from the Sun. This pair is one of two stars named Delta Chamaeleontis, the other being the slightly brighter Delta2 Chamaeleontis located about 6 arcminutes away. Delta Chamaeleontis forms the southernmost component of the constellation's "dipper" or bowl. Together with Gamma Chamaeleontis, they point to a spot that is within 2° of the south celestial pole.

HD 164595 G-type star located in the constellation of Hercules

HD 164595 is a G-type star located in the constellation of Hercules, 28.28 parsecs from Earth that is notably similar to the Sun. With an apparent magnitude of 7.075, the star can be found with binoculars or a small telescope in the constellation Hercules.


  1. 1 2 Longair, Malcolm (2016). Maxwell's Enduring Legacy: A Scientific History of the Cavendish Laboratory. Cambridge University Press. pp. 516–517. ISBN   978-1-316-03341-8.
  2. Green, D.A. (26 May 2016). "Cambridge Low Frequency Surveys". Symposium - International Astronomical Union. 199: 21–24. doi: 10.1017/S0074180900168482 .
  3. "Nomenclature of Celestial Objects - Details on Acronym: 6C". Retrieved 18 March 2020.
  4. Golap, K.; Udaya Shankar, N.; Sachdev, S. (29 March 2018). "A low frequency radio telescope at Mauritius for a Southern sky survey". Journal of Astrophysics and Astronomy. 19 (1–2): 35–53. arXiv: astro-ph/9808062 . doi:10.1007/BF02714890. S2CID   17471378.
  5. [ dead link ]