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David Stanley Evans
David Stanley Evans (28 January 1916 – 14 November 2004) was a British astronomer, noted for his use of lunar occultations to measure stellar angular diameters during the 1950s. Early life and education Evans was born in Cardiff, Wales on 28 January 1916. He was first educated at the Cardiff High School for Boys. He obtained a First Class in the Mathematics Tripos Part II in 1936 and a Distinction in Part III in 1937 from King's College, Cambridge and became a Ph.D. student at Cambridge Observatory in 1937, where he was a student of Sir Arthur Eddington. His Ph.D. degree was awarded in 1941 for a dissertation on “The Formation of the Balmer Series of Hydrogen in Stellar Atmospheres.” Being a conscientious objector to World War II he spent the war years at Oxford with physicist Kurt Mendelssohn where they worked on medical problems relating to the war effort. Over this period he was scientific editor of ''Discovery'' and editor of ''The Observatory''. Career South Africa Eva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occultations
An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks from view (occults) an object in the background. In this general sense, occultation applies to the visual scene observed from low-flying aircraft (or computer-generated imagery) when foreground objects obscure distant objects dynamically, as the scene changes over time. If the closer body does not entirely conceal the farther one, the event is called a ''transit''. Both transit and occultation may be referred to generally as ''occlusion''; and if a shadow is cast onto the observer, it is called an eclipse. The symbol for an occultation, and especially a solar eclipse, is 🝵 (U+1F775 🝵). Occultations by the Moon The term occultation is most frequently used to describe lunar occultations, those relatively frequent occasions when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late-type Star
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coolest (''M'' type). Each letter class is then subdivided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Einstein
Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence formula , which arises from special relativity, has been called "the world's most famous equation". He received the 1921 Nobel Prize in Physics for . Born in the German Empire, Einstein moved to Switzerland in 1895, forsaking his German citizenship (as a subject of the Kingdom of Württemberg) the following year. In 1897, at the age of seventeen, he enrolled in the mathematics and physics teaching diploma program at the Swiss ETH Zurich, federal polytechnic school in Zurich, graduating in 1900. He acquired Swiss citizenship a year later, which he kept for the rest of his life, and afterwards secured a permanent position at the Swiss Patent Office in Bern. In 1905, he submitted a successful PhD dissertation to the University of Zurich. In 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauritania
Mauritania, officially the Islamic Republic of Mauritania, is a sovereign country in Maghreb, Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to Mauritania–Western Sahara border, the north and northwest, Algeria to Algeria–Mauritania border, the northeast, Mali to Mali–Mauritania border, the east and southeast, and Senegal to Mauritania–Senegal border, the southwest. By land area Mauritania is the 11th-largest country in Africa and 28th-largest in the world; 90% of its territory is in the Sahara. Most of its population of some 4.3 million lives in the temperate south of the country; roughly a third of the population is concentrated in the capital and largest city, Nouakchott, on the Atlantic coast. The country's name derives from Mauretania, the Latin name for a region in the ancient Maghreb. It extended from central present-day Algeria to the Atlantic. Berbers occupied what is now Mauritania by the beginning of the third centu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined and slightly less than one-thousandth the mass of the Sun. Its diameter is 11 times that of Earth and a tenth that of the Sun. Jupiter orbits the Sun at a distance of , with an orbital period of . It is the List of brightest natural objects in the sky, third-brightest natural object in the Earth's night sky, after the Moon and Venus, and has been observed since prehistoric times. Its name derives from that of Jupiter (god), Jupiter, the chief deity of ancient Roman religion. Jupiter was the first of the Sun's planets to form, and its inward migration during the primordial phase of the Solar System affected much of the formation history of the other planets. Jupiter's atmosphere consists of 76% hydrogen and 24% helium by mass, with a denser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Scorpii
Beta Scorpii is a Star system, multiple star system in the southern zodiac constellation of Scorpius. It bore the traditional proper name of Acrab , though the International Astronomical Union now regards that name as applying only to the β Scorpii Aa component. Components Observed through a small telescope, Beta Scorpii appears as a binary star with a separation between the two components of 13.5 arcseconds and a combined apparent magnitude of 2.50. This pair, designated β¹ Scorpii and β² Scorpii, form the top branches of a hierarchy of six orbiting components. Hierarchy of orbits in the β Scorpii system β¹ Scorpii, the brighter of the pair, consists of two sub-components, designated β Scorpii A and β Scorpii B, orbiting at an angular separation of 0.3 arcseconds with an orbital period of 610 years. β Scorpii A is itself a spectroscopic binary, with the two components designated β Scorpii Aa (also named Acrab) and β Scorpi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor and experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an Inductive reasoning, inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer Sir William Herschel. He was the nephew of astronomer Caroline Herschel. He studied short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brian Warner (astronomer)
Brian Warner (25 May 1939 – 5 May 2023) was a British South African optical astronomer who was Emeritus Distinguished Professor of natural philosophy at the University of Cape Town. Warner's research included cataclysmic variable stars, pulsars, degenerate stars and binary stars. He also researched and published on the history of astronomy in South Africa. Biography Early life and education Warner was born 25 May 1939 in Crawley Down, Sussex, England. His father was a gardener on a country estate and his mother was a charwoman. He didn't pass his eleven-plus exam, failing in mathematics, but was nonetheless admitted to the East Grinstead County Grammar School on the recommendation of his teacher. As a schoolboy he befriended the noted amateur astronomer Patrick Moore who lived nearby in East Grinstead where Warner and his friends would use Moore's telescope. Warner went to University College London (UCL) in 1958 to study undergraduate astronomy. As a student, he was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonald Observatory
McDonald Observatory is an astronomical observatory located near unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Locke in the Davis Mountains of West Texas, with additional facilities on Mount Fowlkes, approximately to the northeast. The observatory is part of The University of Texas at Austin. It is an organized research unit of the College of Natural Sciences. The observatory produces '' StarDate'', a daily syndicated radio program consisting of short segments related to astronomy that airs on both National Public Radio and commercial radio stations — about 400 affiliates in all. History McDonald Observatory was originally endowed by the Texas banker William Johnson McDonald (1844–1926), who left about $1 million — the bulk of his fortune — to The University of Texas at Austin to endow an astronomical observatory. Edwin Hockaday Fowlkes, step-son of the land's original owner John Chandler Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Texas
The University of Texas at Austin (UT Austin, UT, or Texas) is a public research university in Austin, Texas, United States. Founded in 1883, it is the flagship institution of the University of Texas System. With 53,082 students as of fall 2023, it is also the largest institution in the system. The university is a major center for academic research, with research expenditures totaling $1.06 billion for the 2023 fiscal year. It joined the Association of American Universities in 1929. The university houses seven museums and seventeen libraries, including the Lyndon B. Johnson Presidential Library and the Blanton Museum of Art, and operates various auxiliary research facilities, such as the J. J. Pickle Research Campus and McDonald Observatory. UT Austin's athletics constitute the Texas Longhorns. The Longhorns have won four NCAA Division I National Football Championships, six NCAA Division I National Baseball Championships, sixteen NCAA Division I National Men's Swimming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Science Foundation
The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health. With an annual budget of about $9.9 billion (fiscal year 2023), the NSF funds approximately 25% of all federally supported basic research conducted by the List of American institutions of higher education, United States' colleges and universities. In some fields, such as mathematics, computer science, economics, and the social sciences, the NSF is the major source of federal backing. NSF's director and deputy director are appointed by the president of the United States and Advice and consent, confirmed by the United States Senate, whereas the 24 president-appointed members of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
