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Southern African Large Telescope
The Southern African Large Telescope (SALT) is a 10-metre class optical telescope designed mainly for spectroscopy. It consists of 91 hexagonal mirror segments each with a 1-metre inscribed diameter, resulting in a total hexagonal mirror of 11.1 by 9.8 m. It is located close to the town of Sutherland in the semi-desert region of the Karoo, South Africa. It is a facility of the South African Astronomical Observatory, the national optical observatory of South Africa. SALT is the largest optical telescope in the southern hemisphere. It enables imaging, spectroscopic, and polarimetric analysis of the radiation from astronomical objects out of reach of northern hemisphere telescopes. It is closely based on the Hobby-Eberly Telescope (HET) at McDonald Observatory, with some changes in its design, especially to the spherical aberration corrector. The main driver for these changes were desired improvements to the telescope's field of view. It shares the same fixed mirror ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encircled Energy
The optics term encircled energy refers to a measure of concentration of energy in an optical image, or projected laser at a given range. If a single star is brought to its sharpest focus by a lens giving the smallest image possible with that given lens (called a point spread function or PSF), calculation of the encircled energy of the resulting image gives the distribution of energy in that PSF. Encircled energy is calculated by first determining the total energy of the PSF over the full image plane, then determining the centroid of the PSF. Circles of increasing radius are then created at that centroid and the PSF energy within each circle is calculated and divided by the total energy. As the circle increases in radius, more of the PSF energy is enclosed, until the circle is sufficiently large to completely contain all the PSF energy. The encircled energy curve thus ranges from zero to one. A typical criterion for encircled energy (EE) is the radius of the PSF at which ei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Light (astronomy)
In astronomy, first light is the first use of a telescope (or, in general, a new instrument) to take an astronomical image after it has been constructed. This is often not the first viewing using the telescope; optical tests will probably have been performed to adjust the components. Characteristics The first light image is normally of little scientific interest and is of poor quality, since the various telescope elements are yet to be adjusted for optimum efficiency. Despite this, a first light is always a moment of great excitement, both for the people who design and build the telescope and for the astronomical community, who may have anticipated the moment for many years while the telescope was under construction. A well-known and spectacular astronomical object is usually chosen as a subject. Historical examples The famous Hale Telescope of Palomar Observatory saw first light on 26 January 1949, targeting NGC 2261 under the direction of American astronomer Edwin Powel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five major unincorporated territories, nine United States Minor Outlying Islands, Minor Outlying Islands, and 326 Indian reservations. The United States is also in Compact of Free Association, free association with three Oceania, Pacific Island Sovereign state, sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Palau, Republic of Palau. It is the world's List of countries and dependencies by area, third-largest country by both land and total area. It shares land borders Canada–United States border, with Canada to its north and Mexico–United States border, with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the List of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poland
Poland, officially the Republic of Poland, , is a country in Central Europe. Poland is divided into Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 million people, and the List of European countries by area, seventh largest EU country, covering a combined area of . It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordering seven countries. The territory is characterised by a varied landscape, diverse ecosystems, and Temperate climate, temperate transitional climate. The capital and List of cities and towns in Poland, largest city is Warsaw; other major cities include Kraków, Wrocław, Łódź, Poznań, and Gdańsk. Prehistory and protohistory of Poland, Humans have been present on Polish soil since the Lower Paleolithic, with continuous settlement since the end of the Last Glacial Period over 12,000 years ago. Culturally diverse throughout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the south. Its 16 constituent states have a total population of over 84 million in an area of . It borders Denmark to the north, Poland and Czechia to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr. Settlement in what is now Germany began in the Lower Paleolithic, with various tribes inhabiting it from the Neolithic onward, chiefly the Celts. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South African Department Of Science And Technology
The Department of Science and Innovation (DST; formerly the Department of Science and Technology) is the South African government department responsible for scientific research, including space programmes. The current Minister is Blade Nzimande. Much of the department's work is ultimately carried out through various quasi-independent agencies (although still usually government bodies) including: * the National Research Foundation (South Africa), which receives a substantial proportion of the DST budget to carry out various research support tasks, including supporting key national research infrastructure ("National Research Facilities"), scientific research grant administration and a student grant scheme; * the Council for Scientific and Industrial Research, which acts as a quasi-privatised research and development agency with a specific focus on research of application to industry; * the Technology Innovation Agency, which serves to provide funding to turn innovative research in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thabo Mbeki
Thabo Mvuyelwa Mbeki KStJ (; born 18 June 1942) is a South African politician who was the second president of South Africa from 14 June 1999 to 24 September 2008, when he resigned at the request of his party, the African National Congress (ANC). Before that, he was deputy president under Nelson Mandela between 1994 and 1999. The son of Govan Mbeki, a renowned ANC intellectual, Mbeki has been involved in ANC politics since 1956, when he joined the ANC Youth League, and has been a member of the party's National Executive Committee since 1975. Born in the Transkei, he left South Africa aged twenty to attend university in England, and spent almost three decades in exile abroad, until the ANC was unbanned in 1990. He rose through the organisation in its information and publicity section and as Oliver Tambo's protégé, but he was also an experienced diplomat, serving as the ANC's official representative in several of its African outposts. He was an early advocate for and leader ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
President Of South Africa
The president of South Africa is the head of state and head of government of the Republic of South Africa. The president heads the executive branch of the Government of South Africa and is the commander-in-chief of the South African National Defence Force. Between 1961 and 1994, the office of head of state was the state presidency. The president is elected by the National Assembly, the lower house of Parliament, and is usually the leader of the largest party, which has been the African National Congress since the first multiracial election was held on 27 April 1994. The Constitution limits the president's time in office to two five-year terms. The first president to be elected under the new constitution was Nelson Mandela. The incumbent is Cyril Ramaphosa, who was elected by the National Assembly on 15 February 2018 following the resignation of Jacob Zuma. Under the interim constitution (valid from 1994–96), there was a Government of National Unity, in which a member of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagoon Nebula
The Lagoon Nebula (catalogued as Messier 8 or M8, NGC 6523, Sharpless 25, RCW 146, and Gum 72) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region. The Lagoon Nebula was discovered by Giovanni Hodierna before 1654 and is one of only two star-forming nebulae faintly visible to the eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct cloud-like patch with a definite core. Within the nebula is the open cluster NGC 6530. Characteristics The Lagoon Nebula is estimated to be between 4,000–6,000 light-years away from the Earth. In the sky of Earth, it spans 90' by 40', which translates to an actual dimension of 110 by 50 light years. Like many nebulae, it appears pink in time-exposure color photos but is gray to the eye peering through binoculars or a telescope, human vision having poor color sensitivity at low light levels. The nebula contains a number of Bok globules (dark, collapsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 6744
__NOTOC__ NGC 6744 (also known as Caldwell 101) is an intermediate spiral galaxy about 30 million light-years away in the constellation Pavo (Peacock). It is considered as a Milky Way mimic in the immediate vicinity, displaying flocculent (fluffy) arms and an elongated core. It also has at least one distorted companion galaxy (NGC 6744A) superficially similar to one of the Magellanic Clouds. It was discovered from Parramatta in Australia by Scottish astronomer James Dunlop on 30 June 1826. NGC 6744 lies within the Virgo Supercluster. See also * NGC 2336 - another spiral galaxy of similar size and shape * NGC 1232 * SPT0418-47 - a spiral galaxy of similar size and shape when the universe was 1.4 billion years old * UGC 12158 References External links * NGC 6744, a Milky Way-like spiral galaxy(Wise WISE may refer to: Arts, entertainment, and media * WISE (AM), a radio station licensed to Asheville, North Carolina *WISE-FM, a radio station licensed to Wise, Virginia * W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Alt URL pp. 124–151) and, as such, form part of the Hubble sequence. Most spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as the bulge. These are often surrounded by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 6152
NGC 6152 is an open cluster of stars located in the constellation Norma Norma may refer to: * Norma (given name), a given name (including a list of people with the name) Astronomy * Norma (constellation) *555 Norma, a minor asteroid * Cygnus Arm or Norma Arm, a spiral arm in the Milky Way galaxy Geography *Norma, Laz .... References External links * {{DEFAULTSORT:NGC 6152 6152 Open clusters Norma (constellation) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
