A radio telescope is a specialized antenna and radio receiver used to detect 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.
Timeline of telescopes, observatories, and observing technology.
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 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.
The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on 10,700-foot (3,300 m) Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States. It is a part of the Mount Graham International Observatory.
The National Radio Astronomy Observatory (NRAO) is a federally funded research and development center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc. for the purpose of radio astronomy. NRAO designs, builds, and operates its own high-sensitivity radio telescopes for use by scientists around the world.
Grote Reber was an American pioneer of radio astronomy, which combined his interests in amateur radio and amateur astronomy. He was instrumental in investigating and extending Karl Jansky's pioneering work and conducted the first sky survey in the radio frequencies.
Sir Martin Ryle was an English radio astronomer who developed revolutionary radio telescope systems and used them for accurate location and imaging of weak radio sources. In 1946 Ryle and Derek Vonberg were the first people to publish interferometric astronomical measurements at radio wavelengths. With improved equipment, Ryle observed the most distant known galaxies in the universe at that time. He was the first Professor of Radio Astronomy in the University of Cambridge and founding director of the Mullard Radio Astronomy Observatory. He was the twelfth Astronomer Royal from 1972 to 1982. Ryle and Antony Hewish shared the Nobel Prize for Physics in 1974, the first Nobel prize awarded in recognition of astronomical research. In the 1970s, Ryle turned the greater part of his attention from astronomy to social and political issues which he considered to be more urgent.
McDonald Observatory is an astronomical observatory located near unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Locke in the Davis Mountains of West Texas, with additional facilities on Mount Fowlkes, approximately 1.3 kilometers (0.81 mi) to the northeast. The observatory is part of The University of Texas at Austin. It is an organized research unit of the College of Natural Sciences.
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.
COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical astronomical interferometer with baselines of up to 100 metres, which uses aperture synthesis to observe stars with angular resolution as high as one thousandth of one arcsecond. The principal limitation is that COAST can only image bright stars.
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 part of the Cambridge University, Cavendish Laboratories, Astrophysics Department.
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.
The One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO), Cambridge, UK is an array of radio telescopes designed to perform aperture synthesis interferometry.
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. Construction of the original "Super Cross" telescope with 1.6-kilometre arms began in 1960 by Professor Bernard Y. Mills. It became operational in 1967.
The Mills Cross Telescope was a two-dimensional radio telescope built by Bernard Mills in 1954 at the Fleurs field station of the Australian Commonwealth Scientific and Industrial Research Organisation in the area known now as Badgerys Creek, about 40 km west of Sydney, New South Wales, Australia.
John Evan Baldwin FRS was a British astronomer who worked at the Cavendish Astrophysics Group from 1954. He played a role in the development of interferometry in Radio Astronomy, and later astronomical optical interferometry and lucky imaging. He made the first maps of the radio emission from the Andromeda Galaxy and the Perseus Cluster, and measured the properties of many active galaxies. In 1985 he performed the first Aperture Masking Interferometry observations, and then led the construction and operation of the Cambridge Optical Aperture Synthesis Telescope, and helped develop the lucky imaging method. In 2001 he was awarded the Jackson-Gwilt Medal for his technical contributions to the fields of interferometry and aperture synthesis.
An astronomical interferometer or telescope array is a set of separate telescopes, mirror segments, or radio telescope antennas that work together as a single telescope to provide higher resolution images of astronomical objects such as stars, nebulas and galaxies by means of interferometry. The advantage of this technique is that it can theoretically produce images with the angular resolution of a huge telescope with an aperture equal to the separation, called baseline, between the component telescopes. The main drawback is that it does not collect as much light as the complete instrument's mirror. Thus it is mainly useful for fine resolution of more luminous astronomical objects, such as close binary stars. Another drawback is that the maximum angular size of a detectable emission source is limited by the minimum gap between detectors in the collector array.
The Dominion Radio Astrophysical Observatory is a research facility founded in 1960 and located at Kaleden, British Columbia, Canada. The site houses four radio telescopes: an interferometric radio telescope, a 26-m single-dish antenna, a solar flux monitor, and the Canadian Hydrogen Intensity Mapping Experiment (CHIME) — as well as support engineering laboratories. The DRAO is operated by the Herzberg Institute of Astrophysics of the National Research Council of the Government of Canada. The observatory was named an IEEE Milestone for first radio astronomical observations using VLBI.
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally it was an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects – an optical telescope. Nowadays, the word "telescope" is defined as wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.
The European Pulsar Timing Array (EPTA) is a European collaboration to combine five 100-m class radio-telescopes to observe an array of pulsars with the specific goal of detecting gravitational waves. It is one of several pulsar timing array projects in operation, and one of the four projects comprising the International Pulsar Timing Array, the others being the Parkes Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Indian Pulsar Timing Array.
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