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.
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 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.
The Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, US is the world's largest fully steerable radio telescope, surpassing the Effelsberg 100-m Radio Telescope in Germany. The Green Bank site was part of the National Radio Astronomy Observatory (NRAO) until September 30, 2016. Since October 1, 2016, the telescope has been operated by the independent Green Bank Observatory. The telescope's name honors the late Senator Robert C. Byrd who represented West Virginia and who pushed the funding of the telescope through Congress.
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction. The disturbance may degrade the performance of the circuit or even stop it from functioning. In the case of a data path, these effects can range from an increase in error rate to a total loss of the data. Both man-made and natural sources generate changing electrical currents and voltages that can cause EMI: ignition systems, cellular network of mobile phones, lightning, solar flares, and auroras. EMI frequently affects AM radios. It can also affect mobile phones, FM radios, and televisions, as well as observations for radio astronomy and atmospheric science.
The Northeastern Space Radio Observatory is a 14.2 m (47 ft) radio dish antenna located in the municipality of Eusébio in the state of Ceará, Brazil, approximately 20 kilometres (12 mi) south of Fortaleza. The facility is owned by the National Institute for Space Research (INPE) and managed by the Center of Radio Astronomy and Astrophysics at Universidade Presbiteriana Mackenzie (CRAAM). It was initially funded by several by Brazilian institutions and the United States National Oceanic Atmospheric Administration (NOAA). It has been operating since 1993 and is used primarily for geodetic very long baseline interferometry (VLBI).
Llano de Chajnantor Observatory is the name for a group of astronomical observatories located at an altitude of over 4,800 m (15,700 ft) in the Atacama Desert of northern Chile. The site is in the Antofagasta Region approximately 50 kilometres (31 mi) east of the town of San Pedro de Atacama. The exceptionally arid climate of the area is inhospitable to humans, but creates an excellent location for millimeter, submillimeter, and mid-infrared astronomy. This is because water vapour absorbs and attenuates submillimetre radiation. Llano de Chajnantor is home to the largest and most expensive astronomical telescope project in the world, the Atacama Large Millimeter Array (ALMA). Llano de Chajnantor and the surrounding area has been designated as the Chajnantor Science Reserve by the government of Chile.
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 Five-hundred-meter Aperture Spherical radio Telescope, nicknamed Tianyan, is a radio telescope located in the Dawodang depression (大窝凼洼地), a natural basin in Pingtang County, Guizhou, southwest China. FAST has a 500 m (1,600 ft) diameter dish constructed in a natural depression in the landscape. It is the world's largest filled-aperture radio telescope and the second-largest single-dish aperture, after the sparsely-filled RATAN-600 in Russia.
Arthur Edwin Covington was a Canadian physicist who made the first radio astronomy measurements in Canada. Through these he made the valuable discovery that sunspots generate large amounts of microwaves at the 10.7 cm wavelength, offering a simple all-weather method to measure and predict sunspot activity, and their associated effects on communications. The sunspot detection program has run continuously to this day.
Govind Swarup 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".
The Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Mid West region of Western Australia.
The University of Tokyo Atacama Observatory (TAO) is an astronomical observatory located on the summit of Cerro Chajnantor, at an altitude of 5,640 m (18,500 ft) within a lava dome in the Atacama Desert of northern Chile. The site is located less than 5 km (3.1 mi) north-northeast of the Llano de Chajnantor Observatory, where the Atacama Large Millimeter Array (ALMA) is located, but is over 580 m (1,900 ft) higher in elevation. It is also 28 m (92 ft) higher than the Fred Young Submillimeter Telescope proposed for the same peak.
The Brazilian Decimetric Array (BDA) is a 26-element radio telescope interferometer located in the municipality of Cachoeira Paulista in the state of São Paulo, Brazil. It is capable of performing both solar and stellar observations in three bands: 1.2 - 1.7, 2.8 and 5.6 GHz. The BDA will obtain radio images from the sun with a spatial resolution ~4x6 arc seconds. The main project was conceived and driven by Dr. H. S. Sawant. Financially sponsored by FAPESP and INPE's Astrophysics Division.
National Astronomical Research Institute of Thailand or NARIT is a research institute under the Ministry of Higher Education, Science, Research and Innovation, headquartered in Chiang Mai, Thailand. The main missions of the institute are to carry out, support, and promote the development of astronomy and astrophysics in Thailand through research, public outreach, and educational activities.
Pierre Kauffman Radio Observatory, also known as the Itapetinga Radio Observatory, is a radio observatory located in the municipality of Atibaia in the state of São Paulo in Brazil. It is located approximately 7.5 km (4.7 mi) south of Atibaia and 40 km (25 mi) north of São Paulo. ROI was founded in 1970 by Universidade Presbiteriana Mackenzie (UPM). Control of the facility was passed to the National Institute for Space Research (INPE) in 1982. Today it is managed jointly by INPE, UPM, University do Vale do Paraíba (Univap), Universidade de São Paulo (USP), and Universidade Federal de Itajubá (UNIFEI). In addition to the telescopes, the observatory has living quarters for visiting scientists. ROI is located inside a small radio quiet zone. It was renamed in 2016 after Pierre Kauffman.
Vijay Kumar Kapahi was an Indian astrophysicist and the director of the National Centre for Radio Astrophysics, an autonomous division of Tata Institute of Fundamental Research. Known for his research on radio galaxies, quasars and observational cosmology, Kapahi was an elected fellow of all the three major Indian science academies – Indian Academy of Sciences, Indian National Science Academy and National Academy of Sciences, India – as well as of the Maharashtra Academy of Sciences. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology for his contributions to physical sciences in 1987.
