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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 long and tall cylindrical parabolic antenna. It operates at a frequency of 326.5 MHz with a maximum bandwidth of 15 MHz at the front end. Design The Ooty Radio Telescope has been designed and fabricated with domestic Indian technological resources. The ORT was completed in 1970 and continues to be one of the most sensitive radio telescopes in the world. Observations made using this telescope have led to important discoveries and to explain various phenomena occurring in the Solar System and in other celestial bodies. The reflecting surface of the telescope is made of 1,100 thin stainless-steel wires running parallel to each other for the entire length of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Telescopes
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. Since astronomical radio sources such as planets, stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in tracking and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Telescope
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. Since astronomical radio sources such as planets, stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in tracking an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Telescope
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. Since astronomical radio sources such as planets, stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in tracking an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasars
A quasar is an extremely luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up because of friction and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosities thousands of times greater than that of a galaxy such as the Milky Way. Usually, quasars are categorized as a subclass of the more general category of AGN. The redshifts of quasars are of cosmological origin. The term originated as a contraction of "quasi-stellar '' tar-like' radio source"—because quasars were first identified during the 1950s as sources of radio-wave emission of unknown physical origin—and when identifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Radio Telescopes
This is a list of radio telescopes – over one hundred – that are or have been used for radio astronomy. The list includes both single dishes and interferometric arrays. The list is sorted by region, then by name; unnamed telescopes are in reverse size order at the end of the list. The first radio telescope was invented in 1932, when Karl Jansky at Bell Telephone Laboratories observed radiation coming from the Milky Way. Africa Antarctica Asia Australia Europe North America South America Arctic Ocean Atlantic Ocean Indian Ocean Pacific Ocean Space-based Under construction or planned construction Proposed telescopes Gallery of big dishes File:FastTelescope*8sep2015.jpg, alt=Five hundred meter Aperture Spherical Telescope under construction, The 500 meter Five hundred meter Aperture Spherical Telescope (FAST), under construction, China (2016) File:GBT.png, alt=Green Bank Telescope, The 100 meter Green Bank Telescope, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Astronomy
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. Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolution, as the resolving power of an interferometer is set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Govind Swarup
Govind Swarup (March 23, 1929 – September 7, 2020) was a pioneer in radio astronomy. In addition to research contributions in multiple areas of astronomy and astrophysics, he was a driving force behind the building of "ingenious, innovative and powerful observational facilities for front-line research in radio astronomy". Swarup was the key scientist behind concept, design and installation of the Ooty Radio Telescope (Ootacamund, India) and the Giant Metrewave Radio Telescope (GMRT) near Pune. Swarup was the founding director of the National Centre for Radio Astrophysics (NCRA) at the Tata Institute of Fundamental Research (TIFR). Under his leadership, a strong group in radio astrophysics was built at Tata Institute of Fundamental Research that is comparable to the best in the world. He published over 125 research papers, edited 4 books, and held at least two patents. He contributed to the fields of solar radio emission, radio galaxies, quasars, pulsars, interplanetary scint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channel 37
Channel 37 is an intentionally unused ultra-high frequency (UHF) television broadcasting channel by countries in most of ITU region 2 such as the United States, Canada, Mexico and Brazil. The frequency range allocated to this channel is important for radio astronomy, so all broadcasting is prohibited within a window of frequencies centred typically on . Similar reservations exist in portions of the Eurasian and Asian regions, although the channel numbering varies. History Channel 37 in System M and N countries occupied a band of UHF frequencies from . This band is particularly important to radio astronomy because it allows observation in a region of the spectrum in between the dedicated frequency allocations near 410 MHz and 1.4 GHz. The area reserved or unused differs from nation to nation and region to region (as for example the EU and British Isles have slightly different reserved frequency areas). One radio astronomy application in this band is for very-long-baselin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Storm
A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth's magnetic field. The disturbance that drives the magnetic storm may be a solar coronal mass ejection (CME) or (much less severely) a co-rotating interaction region (CIR), a high-speed stream of solar wind originating from a coronal hole. The frequency of geomagnetic storms increases and decreases with the sunspot cycle. During solar maximum, geomagnetic storms occur more often, with the majority driven by CMEs. The increase in the solar wind pressure initially compresses the magnetosphere. The solar wind's magnetic field interacts with the Earth's magnetic field and transfers an increased energy into the magnetosphere. Both interactions cause an increase in plasma movement through the magnetosphere (driven by increased electric fields inside the magnetosphere) and an increase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Scintillation
In astronomy, interplanetary scintillation refers to random fluctuations in the intensity of radio waves of celestial origin, on the timescale of a few seconds. It is analogous to the twinkling one sees looking at stars in the sky at night, but in the radio part of the electromagnetic spectrum rather than the visible one. Interplanetary scintillation is the result of radio waves traveling through fluctuations in the density of the electron and protons that make up the solar wind. Early study Scintillation, meaning rapid modification, in radio waves due to the small scale structures in the ionosphere, known as ionospheric scintillation, was observed as early as 1951 by Antony Hewish, and he then reported irregularities in radiation received during an observation of a bright radio source in Taurus in 1954. Hewish considered various possibilities, and suggested that irregularities in the solar corona would cause scattering by refraction and could produce the irregularities he observed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bang Model
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the earliest known periods through its subsequent large-scale form. These models offer a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large-scale structure. The overall uniformity of the Universe, known as the flatness problem, is explained through cosmic inflation: a sudden and very rapid expansion of space during the earliest moments. However, physics currently lacks a widely accepted theory of quantum gravity that can successfully model the earliest conditions of the Big Bang. Crucially, these models are compatible with the Hubble–Lemaître law—the observation that the farther away a galaxy is, the faster it is movin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steady State Theory
In cosmology, the steady-state model, or steady state theory is an alternative to the Big Bang theory of evolution of the universe. In the steady-state model, the density of matter in the expanding universe remains unchanged due to a continuous creation of matter, thus adhering to the perfect cosmological principle, a principle that asserts that the observable universe is practically the same at any time and any place. While from the 1940s to the 1960s the astrophysical community was equally divided between supporters of the Big Bang theory and supporters of the steady-state theory, it is now rejected by the vast majority of cosmologists, astrophysicists and astronomers, as the observational evidence points to a hot Big Bang cosmology with a finite age of the universe, which the steady-state model does not predict. History In the 13th century, Siger of Brabant authored the thesis ''The Eternity of the World'', which argued that there was no first man, and no first specimen of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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