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Alan William James Cousins
Alan William James Cousins Fellow of the Royal Astronomical Society, FRAS (8 August 1903 – 11 May 2001) was a South African astronomer. His career spanned 70 years during which time he concentrated on the measurement of variable stars, including the measurement of the two sinusoidal periods of Gamma Doradus. The UBV photometric system for measuring stellar fluxes he devised in his 1990s became a standard known as the "Cousins system". Education and career He was born in Three Anchor Bay, Cape Town, the eldest of four children, and his father Clarence Wilfred Cousins was a senior civil servant who served for a time as Secretary of Labour. His grandfather on his mother's side was Sir James Murray (lexicographer), James Murray, first editor of the ''Oxford English Dictionary'', and Cousins attended Murray's funeral at the age of 11. Cousins' interest in Astronomy was aroused first by the sighting of Halley's Comet in 1910 and then by a book on Astronomy ("The Stars" by E.Hawk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three Anchor Bay
Three Anchor Bay is a suburb of Cape Town in the Western Cape province of South Africa. Small anchorage in Table Bay. The name, first encountered in 1661, possibly refers to anchors securing chains stretched as defence across the bay. The form Drieankerbaai is preferred for official purposes. Afrikaans language author and poet Ingrid Jonker drowned herself at the nearby beach on July 19, 1965. The National Sea Rescue Institute is headquartered there. In the period May 2020 through February 2021 there were 25 apartments sold in the suburb at an average price of R 34361 / m² References 4Lance Real Estate Three Anchor Bay Property Review {{Authority control Suburbs of Cape Town ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Flux
In radiometry, radiant flux or radiant power is the radiant energy emitted, reflected, transmitted, or received per unit time, and spectral flux or spectral power is the radiant flux per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. The SI unit of radiant flux is the watt (W), one joule per second (), while that of spectral flux in frequency is the watt per hertz () and that of spectral flux in wavelength is the watt per metre ()—commonly the watt per nanometre (). Mathematical definitions Radiant flux Radiant flux, denoted Φe ('e' for "energetic", to avoid confusion with photometric quantities), is defined as \Phi_\mathrm = \frac :Q_\mathrm = \int_ \mathbf\cdot \hat\mathbf\, dA where *''t'' is the time; *''Q''e is the radiant energy flux of the field out of a closed surface \Sigma; *S is the Poynting vector, representing the current density of radiant energy; *n is the normal vector of a point on \Sigma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerald Kron
Gerald Kron (April 6, 1913 – April 9, 2012) was an American astronomer who was one of the pioneers of high-precision photometry with photoelectric instrumentation. He discovered the first starspot and made the first photometric observation of a stellar flare. A graduate of the University of Wisconsin-Madison, where he earned a Master of Science degree in mechanical engineering in 1934, Kron became interested in astronomy, which he studied under Joel Stebbins. Stebbins arranged for Kron to enter the University of California at Berkeley, where he received his doctorate in astronomy in 1938. During World War II, Kron served with the Radiation Laboratory at the Massachusetts Institute of Technology, and participated in the development of microwave radar. He later became the head of the Special Devices Group at the Naval Ordnance Test Station (NOTS) at Inyokern, California, where he conducted studies on solid fuel rockets, and developed radio transponders for the Manhattan Project' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric Effect
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid state and quantum chemistry to draw inferences about the properties of atoms, molecules and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission. The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light's intensity or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Durban
Durban ( ) ( zu, eThekwini, from meaning 'the port' also called zu, eZibubulungwini for the mountain range that terminates in the area), nicknamed ''Durbs'',Ishani ChettyCity nicknames in SA and across the worldArticle on ''news24.com'' from 25 October 2017. Retrieved 2021-03-05.The names and the naming of Durban Website ''natalia.org.za'' (pdf). Retrieved 2021-03-05. is the third most populous city in after and |
Fabry–Pérot Interferometer
In optics, a Fabry–Pérot interferometer (FPI) or etalon is an optical cavity made from two parallel reflecting surfaces (i.e.: thin mirrors). Optical waves can pass through the optical cavity only when they are in resonance with it. It is named after Charles Fabry and Alfred Perot, who developed the instrument in 1899. ''Etalon'' is from the French ''étalon'', meaning "measuring gauge" or "standard". Etalons are widely used in telecommunications, lasers and spectroscopy to control and measure the wavelengths of light. Recent advances in fabrication technique allow the creation of very precise tunable Fabry–Pérot interferometers. The device is technically an interferometer when the distance between the two surfaces (and with it the resonance length) can be changed, and an etalon when the distance is fixed (however, the two terms are often used interchangeably). Basic description The heart of the Fabry–Pérot interferometer is a pair of partially reflective glass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newcastle-upon-Tyne
Newcastle upon Tyne ( RP: , ), or simply Newcastle, is a city and metropolitan borough in Tyne and Wear, England. The city is located on the River Tyne's northern bank and forms the largest part of the Tyneside built-up area. Newcastle is also the most populous city of North East England. Newcastle developed around a Roman settlement called Pons Aelius and the settlement later took the name of a castle built in 1080 by William the Conqueror's eldest son, Robert Curthose. Historically, the city’s economy was dependent on its port and in particular, its status as one of the world's largest ship building and repair centres. Today, the city's economy is diverse with major economic output in science, finance, retail, education, tourism, and nightlife. Newcastle is one of the UK Core Cities, as well as part of the Eurocities network. Famous landmarks in Newcastle include the Tyne Bridge; the Swing Bridge; Newcastle Castle; St Thomas’ Church; Grainger Town including Grey's M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barney Barnato
Barney Barnato (21 February 1851 – 14 June 1897), born Barnet Isaacs, was a British Randlord, one of the entrepreneurs who gained control of diamond mining, and later, gold mining in South Africa from the 1870s up to World War I. He is perhaps best remembered as being a rival of Cecil Rhodes. Early life Barney Barnato claimed that he had the same birthday as Cecil Rhodes (5 July 1853). Most biographies give his date of birth as 5 July 1852. However, his birth certificate (supported by census data) shows he was born Barnet Isaacs in Aldgate, London on 21 February 1851, the son of Isaac and Leah Isaacs. He was educated by Moses Angel at the Jews' Free School. He had a hard life, and is reputed to have begged pass-outs (re-entry tickets) from theatre-leavers at the Garrick Theatre in Leman Street, to sell them on to others for a halfpenny. For a while he became a prizefighter and music-hall turn.Stephen Inwood (2005). ''City of cities: The birth of modern London''. London: Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander William Roberts
The Hon. Alexander William Roberts FRSE FRAS FRSSA (4 December 1857–21 January 1938) was Scottish-born, South African teacher and an amateur astronomer. He was an expert on the stars of the southern hemisphere and did much mapping of these stars. He was affectionately known as Roberts of Lovedale. Life He was born in Farr, in the county of Sutherland, Scotland. His father, William Henry Roberts, moved to Admiralty House, on Newhaven Road in Leith, north of Edinburgh in his youth.Edinburgh Post Office Directory 1865 Alexander was educated at St James Free Church School in Leith. He trained as a teacher at Moray House in Edinburgh and at the Free Church College for Teachers also in Edinburgh. From 1877 until 1881 he served as an assistant teacher at the North School, in Wick, Scotland. In 1881 he returned to Edinburgh to take on an assistant role at the University of Edinburgh. As a youth he developed an interest in astronomy, but, after applying for a post at the Edi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquila (constellation)
Aquila is a constellation on the celestial equator. Its name is Latin for 'eagle' and it represents the bird that carried Zeus/Jupiter's thunderbolts in Greek-Roman mythology. Its brightest star, Altair, is one vertex of the Summer Triangle asterism. The constellation is best seen in the northern summer, as it is located along the Milky Way. Because of this location, many clusters and nebulae are found within its borders, but they are dim and galaxies are few. History Aquila was one of the 48 constellations described by the second-century astronomer Ptolemy. It had been earlier mentioned by Eudoxus in the fourth century BC and Aratus in the third century BC. It is now one of the 88 constellations defined by the International Astronomical Union. The constellation was also known as ''Vultur volans'' (the flying vulture) to the Romans, not to be confused with ''Vultur cadens'' which was their name for Lyra. It is often held to represent the eagle which held Zeus's/Jupiter's t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nova
A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramatic appearance of a nova vary, depending on the circumstances of the two progenitor stars. All observed novae involve white dwarfs in close binary systems. The main sub-classes of novae are classical novae, recurrent novae (RNe), and dwarf novae. They are all considered to be cataclysmic variable stars. Classical nova eruptions are the most common type. They are likely created in a close binary star system consisting of a white dwarf and either a main sequence, subgiant, or red giant star. When the orbital period falls in the range of several days to one day, the white dwarf is close enough to its companion star to start drawing accreted matter onto the surface of the white dwarf, which creates a dense but shallow atmosphere. This atmosphe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
