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South 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 altit ... [...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 ... [...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 Powell ... [...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 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and 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 most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous member state of the European Union. Warsaw is the nation's capital and largest metropolis. Other major cities include Kraków, Wrocław, Łódź, Poznań, Gdańsk, and Szczecin. Poland has a temperate transitional climate and its territory traverses the Central European Plain, extending from Baltic Sea in the north to Sudeten and Carpathian Mountains in the south. The longest Polish river is the Vistula, and Poland's highest point is Mount Rysy, situated in the Tatra mountain range of the Carpathians. The country is bordered by Lithuania and Russia to the northeast, Belarus and Ukraine to the east, Slovakia and the Czech Republic to the south, and Germany to the west. It also shares maritime boundaries with Denmark and Sweden. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic 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 financial centre is Frankfurt; the largest urban area is the Ruhr. 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 bulk of the Holy Roman Empire. During the 16th ce ... [...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 int ... [...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 o ... [...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 President of South Africa, state presidency. The president is elected by the National Assembly of South Africa, National Assembly, the lower house of Parliament of South Africa, 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 of South Africa, National Assembly on 15 February 2018 following the resignation of J ... [...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 UGC 12158 or PGC 69533 is an Sb-type barred spiral galaxy located approximately away from Earth in the constellation of Pegasus. Its tight spiral disk spans approximately across, whose scale at heliocentric distance is about 36.9 kiloparsecs p ... R ... [...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 . Most spiral galaxies consist of a flat, rotating containing s, gas and dust, and a central concentration of stars known as the |
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, Lazi .... References External links * {{DEFAULTSORT:NGC 6152 6152 Open clusters Norma (constellation) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
