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. Because an antenna sees only one spot at a time, the image is produced by scanning the sky line by line, using earth rotation and antenna motion.
An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant or Stonehenge.
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.
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth or in space. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.
The National Optical Astronomy Observatory (NOAO) is the United States national observatory for ground-based nighttime ultraviolet-optical-infrared (OUVIR) astronomy. The National Science Foundation (NSF) funds NOAO to provide forefront astronomical research facilities for US astronomers. However, professional astronomers from any country in the world may apply to use the telescopes operated by NOAO under the NSF's "open skies" policy. Astronomers submit proposals for peer review to gain access to the telescopes which are scheduled every night of the year for observations. The combination of truly open access and the merit based science proposal process makes NOAO unique in the world.
The Giant Metrewave Radio Telescope (GMRT), located near Pune, Junnar, near Narayangaon at khodad 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. It is an interferometric array with baselines of up to 25 kilometres (16 mi). It was recently upgraded with new receivers, after which it is also known as the Upgraded Giant Metrewave Radio Telescope (uGMRT).
The Low-Frequency Array, or LOFAR, is a large radio telescope network located mainly in the Netherlands, completed in 2012 by ASTRON, the Netherlands Institute for Radio Astronomy and its international partners, and operated by ASTRON's radio observatory, of the Netherlands Organisation for Scientific Research.
The Paul Wild Observatory, also known as the Narrabri Observatory and Culgoora Observatory, is an astronomical research facility located about 24 km west of Narrabri, New South Wales, Australia. It is the home of the Australia Telescope Compact Array, and the Culgoora Solar Observatory.
The Special Astrophysical Observatory of the Russian Academy of Science is an astronomical observatory, set up in 1966 in the USSR, and now operated by the Russian Academy of Sciences. Based in the Bolshoi Zelenchuk Valley of the Greater Caucasus near the village of Nizhny Arkhyz, the observatory houses the BTA-6 and RATAN-600, an optical and radio telescope, respectively. The two instruments are about 20 km (12 mi) apart.
The Nobeyama Radio Observatory (NRO) is a division of the National Astronomical Observatory of Japan (NAOJ) and consists of three radio instruments located near Minamimaki, Nagano at an elevation of 1350m.
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.
Aryabhatta Research Institute of Observational Sciences (ARIES) is a leading research institute in Nainital, Uttarakhand which specializes in Astronomy, Solar Physics, Astrophysics and Atmospheric Sciences. It is an autonomous body under the Department of Science and Technology (DST), Government of India, the institute is situated at Manora Peak, about 9 km from Nainital, a popular hill station.
The Gauribidanur Radio Observatory is a radio telescope observatory located at Gauribidanur, near Bengaluru. It is operated jointly by Raman Research Institute and the Indian Institute of Astrophysics. The observatory has been in operation since 1976.
The Chinese Deep Space Network (CDSN) is a network of large antennas and communication facilities that are used for the interplanetary spacecraft missions of China. It is managed by the China Satellite Launch and Tracking Control General (CLTC), which reports to the People's Liberation Army Strategic Support Force. They also deal with radio-astronomical and radar observations.
The Large Latin American Millimeter Array (LLAMA) is a single-dish 12 m Nasmyth optics antenna which is under construction in the Puna de Atacama desert in the Province of Salta, Argentina. The primary mirror accuracy will allow observation from 40 GHz up to 900 GHz. It is also planned to install a bolometer camera at millimeter wavelengths. After installation it will be able to join other similar instruments to perform Very Large Base Line Interferometry or to work in standalone mode. Financial support is provided by the Argentinian and Brazilian governments. The total cost of construction, around US$20 million, and operation as well as the telescope time use will be shared equally by the two countries. Construction planning started in July 2014 after the formal signature of an agreement between the main institutions involved.
2015 HM10 is an irregular shaped asteroid and sub-kilometer near-Earth object that passed near the Earth on 7 July 2015, at a distance of 442,000 kilometers or 1.15 lunar distances.
The Geodetic Observatory Wettzell is located atop the 616 meter-high mountain Wagnerberg, west of the village Wettzell in the German district Cham in the Bavarian Forest.
The Tien Shan Astronomical Observatory is an astronomical observatory located in the Tien Shan Mountains at 2,800 meters altitude, 30 kilometers south of the city of Almaty in Kazakhstan. It was assigned to the Sternberg Astronomical Institute (GAISh) until the collapse of the Soviet Union. The observatory is a state-owned scientific institution that belongs to the Astrophysical Institute after V.G. Fesenkov. It is often used for photometric investigations of variable stars in the Milky Way, eclipsing systems.
AZ Phoenicis is a variable star in the constellation of Phoenix. It has an average visual apparent magnitude of 6.47, so it is at the limit of naked eye visibility. From parallax measurements by the Gaia spacecraft, it is located at a distance of 322 light-years from Earth. Its absolute magnitude is calculated at 1.65.
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