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Gérard De Vaucouleurs
Gérard Henri de Vaucouleurs (25 April 1918 – 7 October 1995) was a French astronomer. Life and career Born in Paris, he had an early interest in amateur astronomy and received his undergraduate degree in 1939 at the Sorbonne in that city. After military service in World War II, he resumed his pursuit of astronomy. He was married to fellow astronomer Antoinette de Vaucouleurs on October 31, 1944, and the couple would frequently collaborate on astronomical research. Fluent in English, he spent 1949–51 in England, 1951–57 in Australia, the latter at Mount Stromlo Observatory, 1957–58 at Lowell Observatory in Arizona and 1958–60 at Harvard. In 1960 he was appointed to the University of Texas at Austin, where he spent the rest of his career. He died of a heart attack in his home in Austin at the age of 77. His earliest work had concerned the planet Mars and while at Harvard he used telescope observations from 1909 to 1958 to study the areographic coord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris, France
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the List of cities proper by population density, 30th most densely populated city in the world in 2020. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, Fashion capital, fashion, gastronomy, and science. For its leading role in the arts and sciences, as well as its very early system of street lighting, in the 19th century it became known as "the City of Light". Like London, prior to the Second World War, it was also sometimes called Caput Mundi#Paris, the capital of the world. The City of Paris is the centre of the Île-de-France Regions of France, region, or Paris Region, with an estimated population of 12,262,544 in 2019, or about 19% of the population of France, making the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Four Corners region with Utah to the north, Colorado to the northeast, and New Mexico to the east; its other neighboring states are Nevada to the northwest, California to the west and the Mexican states of Sonora and Baja California to the south and southwest. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912. Historically part of the territory of in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase. Southern Arizona is known for its desert cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 ''Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PNAS
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are ava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julien Peridier
Julien Péridier (1882 – April 19, 1967) was a French electrical engineer and amateur astronomer. For his work he was made an Officer of the Legion of Honour. In 1933 he founded a private observatory at Le Houga (Gers), France. After his death, his library and instruments were acquired by the McDonald Observatory at the University of Texas for use in teaching astronomy. The double refracting telescope at Le Houga was used extensively for studies of the planets and the teaching of young astronomers. In 1959 his observatory was part of an observational campaign regarding an occultation of Regulus by Venus. The team of Harvard observers at Le Houga was led by Gérard de Vaucouleurs, who had previously collaborated with Mr. Péridier on studies at the observatory. The success of the 1959 work started a five-year collaboration with NASA on photometry of the Moon and planets using a reflector. He was married to Adrienne Blanc-Péridier, who was an accomplished author of one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Wilson Morgan
William Wilson Morgan (January 3, 1906 – June 21, 1994) was an American astronomer and astrophysicist. The principal theme in Morgan's work was stellar and galaxy classification. He is also known for helping prove the existence of spiral arms in our galaxy. In addition to his scientific achievements he served as a professor and as astronomy director for University of Chicago, and was the managing editor for George Hale's Astrophysical Journal. Scientific achievements Along with Philip Keenan he developed the MK system for the classification of stars through their spectra. He also developed several galaxy morphological classification systems, including the first systems to use the physical, quantifiable properties of galaxies, as opposed to simple, qualitative, eyeball estimates favoured by Edwin Hubble. He invented the now widely used classification cD for massive galaxies in the centres of galaxy clusters. In 1970, along with astronomer Laura P. Bautz, they created the stil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Color–magnitude Diagram
The galaxy color–magnitude diagram shows the relationship between absolute magnitude (a measure of luminosity) and mass of galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. .... A preliminary description of the three areas of this diagram was made in 2003 by Eric F. Bell et al. from the COMBO-17 survey that clarified the bimodal distribution of red and blue galaxies as seen in analysis of Sloan Digital Sky Survey data and even in de Vaucouleurs's 1961 de Vaucouleurs modified Hubble sequence, analyses of Galaxy morphological classification, galaxy morphology. Features The diagram has three main features: the red sequence, the green valley, and the blue cloud. The red sequence includes most red galaxies, which are generally elliptical galaxy, elliptical galaxies. The blue cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edwin Hubble
Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an Americans, American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previously thought to be clouds of dust and gas and classified as "nebulae" were actually Galaxy, galaxies beyond the Milky Way. He used the strong direct period-luminosity relation, relationship between a classical Cepheid variable's luminosity and periodic function, pulsation period (discovered in 1908 by Henrietta Swan Leavitt) for scaling cosmic distance ladder, galactic and extragalactic distances. Hubble provided evidence that the recessional velocity of a galaxy increases with its distance from the Earth, a property now known as "Hubble's law", although it had been proposed two years earlier by Georges Lemaître. The Hubble law implies that the universe is expanding. A decade before, the American astronomer Vesto Slipher had provid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Société Astronomique De France
The Société astronomique de France (SAF; ), the French astronomical society, is a non-profit association in the public interest organized under French law (Association loi de 1901). Founded by astronomer Camille Flammarion in 1887, its purpose is to promote the development and practice of astronomy. History SAF was established by Camille Flammarion and a group of 11 persons on 28 January 1887 in Flammarion's apartment at 16 rue Cassini, 75014 Paris, close to the Paris Observatory. Open to all, SAF includes both professional and amateur astronomers as members, from France and abroad.Ferlet R. (2003) "The Société Astronomique de France in the Astronomical Landscape: Evolution and Prospects." In: ''Organizations and Strategies in Astronomy''. Astrophysics and Space Science Library, vol 296. Springer, Dordrecht. Its objective was defined at the time of its establishment as: "A Society is founded with the aim to bring together people involved practically or theoretically in As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Astronomical Society
The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the advancement of astronomy and closely related branches of science, while the secondary purpose includes enhancing astronomy education and providing a political voice for its members through lobbying and grassroots activities. Its current mission is to enhance and share humanity's scientific understanding of the universe as a diverse and inclusive astronomical community. History The society was founded in 1899 through the efforts of George Ellery Hale. The constitution of the group was written by Hale, George Comstock, Edward Morley, Simon Newcomb and Edward Charles Pickering. These men, plus four others, were the first Executive Council of the society; Newcomb was the first president. The initial membership was 114. The AAS name of the so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Sequence
The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often colloquially known as the Hubble tuning-fork diagram because the shape in which it is traditionally represented resembles a tuning fork. Hubble's scheme divided regular galaxies into three broad classes – ellipticals, lenticulars and spirals – based on their visual appearance (originally on photographic plates). A fourth class contains galaxies with an irregular appearance. The Hubble sequence is the most commonly used system for classifying galaxies, both in professional astronomical research and in amateur astronomy. Classes of galaxies Ellipticals On the left (in the sense that the sequence is usually drawn) lie the ellipticals. Elliptical galaxies have relatively smooth, featureless light distributions and appear as ellipses in photographic images. They are denoted by the letter E, followed by an integer ''n'' representing their degree of ellipti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
