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Antoinette De Vaucouleurs
Antoinette de Vaucouleurs (November 14, 1921, Paris, France-August 29, 1987, Austin, Texas, USA) was an astronomer who worked in the Astronomy Department of the University of Texas at Austin for 25 years (1961-1986) when few women worked in the field. In addition to ongoing collaborations with her husband, Gérard de Vaucouleurs, she carried out her own research in spectroscopy. Her contributions (and Gérard's) were recognized in a '' festschrift'' in 1988, entitled ''The World of Galaxies''. Early life and education Antoinette Piétra was born on November 14, 1921, in Paris, France. She married Gérard de Vaucouleurs on October 31, 1944. De Vaucouleurs studied mathematics, physics, and astronomy at the Sorbonne from 1944 to 1948. Career De Vaucouleurs worked as a laboratory spectroscopist at the Institut d'Astrophysique de Paris from 1948 to 1949. From 1950 to 1951, she acted as a voluntary assistant at the University of London Observatory (ULO)'s Mill Hill Obser ... [...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] |
Harvard Observatory
The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United States, and was founded in 1839. With the Smithsonian Astrophysical Observatory, it forms part of the Center for Astrophysics Harvard & Smithsonian. HCO houses a collection of approximately 500,000 astronomical plates taken between the mid-1880s and 1989 (with a gap from 1953–1968). This 100-year coverage is a unique resource for studying temporal variations in the universe. The Digital Access to a Sky Century @ Harvard project is digitally scanning and archiving these photographic plates. History In 1839, the Harvard Corporation voted to appoint William Cranch Bond, a prominent Boston clockmaker, as "Astronomical Observer to the University" (at no salary). This marked the founding of the Harvard College Observatory. HCO's first teles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Catalogue Of Bright Galaxies
Reference is a relationship between objects in which one object designates, or acts as a means by which to connect to or link to, another object. The first object in this relation is said to ''refer to'' the second object. It is called a ''name'' for the second object. The second object, the one to which the first object refers, is called the ''referent'' of the first object. A name is usually a phrase or expression, or some other symbolic representation. Its referent may be anything – a material object, a person, an event, an activity, or an abstract concept. References can take on many forms, including: a thought, a sensory perception that is audible ( onomatopoeia), visual (text), olfactory, or tactile, emotional state, relationship with other, spacetime coordinate, symbolic or alpha-numeric, a physical object or an energy projection. In some cases, methods are used that intentionally hide the reference from some observers, as in cryptography. References feature in man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (16 kpc) and the possible dwarf irregular galaxy known as the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is approximately across. It is roughly a hundredth as massive as the Milky WayMagellanic Cloud . ''''. 2009. Encyclopædia Britannica Online. 30 Aug. 2009. and is the fourth-largest g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Von Struve
Karl Hermann von Struve ( – 12 August 1920) was a Baltic German astronomer. In Russian, his name is sometimes given as ''German Ottovich Struve'' (Герман Оттович Струве) or ''German Ottonovich Struve'' (Герман Оттонович Струве). Hermann von Struve was a part of the famous group of astronomers from the Struve family, which also included his grandfather Friedrich Georg Wilhelm von Struve, father Otto Wilhelm von Struve, brother Ludwig Struve and nephew Otto Struve. Unlike other astronomers of the Struve family, Herman spent most of his career in Germany. Continuing the family tradition, Struve's research was focused on determining the positions of stellar objects. He was particularly known for his work on satellites of planets of the Solar System and development of the intersatellite method of correcting their orbital position. The mathematical Struve function is named after him. Biography Herman was born in 1854 in Tsarskoye Selo, a forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seyfert Galaxies
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable. Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. The accretion discs are believed to be the source of the observed ultraviolet radiation. Ultraviolet emission and absorption lines provide the best diagnostics for the composition of the surrounding material. Seen in visible light, most Seyfert galaxies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morgan-Keenan System
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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Astronomical Society
(Whatever shines should be observed) , predecessor = , successor = , formation = , founder = , extinction = , merger = , merged = , type = NGO, learned society , status = Registered charity , purpose = To promote the sciences of astronomy & geophysics , professional_title = Fellow of the Royal Astronomical Society (FRAS) , headquarters = Burlington House , location = Piccadilly, London , coords = , region_served = , services = , membership = , language = , general = , leader_title = Patron , leader_name = King Charles III , leader_title2 = President , leader_name2 = Mike Edmunds , leader_title3 = Executive Director , leader_name3 = Philip Diamond , leader_title4 = , leader_name4 = , key_peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UBV Photometric System
The UBV photometric system (from ''Ultraviolet, Blue, Visual''), also called the Johnson system (or Johnson-Morgan system), is a photometric system usually employed for classifying stars according to their colors. It was the first standardized photometric system. The apparent magnitudes of stars in the system are often used to determine the color indices B-V and U-B, the difference between the B and V magnitudes and the U and B magnitudes respectively. The choice of colors on the blue end of the spectrum was assisted by the bias that photographic film has for those colors. It was introduced in the 1950s by American astronomers Harold Lester Johnson and William Wilson Morgan. A telescope and the telescope at McDonald Observatory were used to define the system. The filters are selected so that the mean wavelengths of response functions (at which magnitudes are measured to mean precision) are 364 nm for U, 442 nm for B, 540 nm for V. Zero points were calibrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harold Johnson (astronomer)
Harold Lester Johnson (April 17, 1921 – April 2, 1980) was an American astronomer. Harold Johnson was born in Denver, Colorado, on April 17, 1921. He received his early education in Denver public schools and went to the University of Denver, graduating with a degree in mathematics in 1942. Johnson was recruited by the MIT Radiation Laboratory to work on World War II related radar research. After the war Johnson began graduate studies in astronomy at University of California, Berkeley where he completed his thesis under Harold Weaver in 1948. In the following years working at Lowell Observatory, University of Wisconsin–Madison, Yerkes Observatory (where he met William Wilson Morgan), McDonald Observatory, University of Texas–Austin, the Lunar and Planetary Laboratory in Tucson, Arizona, and the National Autonomous University of Mexico he applied his instrumental and electronic talents to developing and calibrating astronomical photoelectric detectors. He died of a he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Vaucouleurs's Law
de Vaucouleurs's law, also known as the de Vaucouleurs profile or de Vaucouleurs model, describes how the surface brightness I of an elliptical galaxy varies as a function of apparent distance R from the center of the galaxy: : \ln I(R) = \ln I_ - k R^. By defining ''Re'' as the radius of the isophote containing half of the total luminosity of the galaxy, the half-light radius, de Vaucouleurs profile may be expressed as: : \ln I(R) = \ln I_ + 7.669 \left 1 - \left( \frac \right)^ \right or : I(R) = I_ e^ where ''Ie'' is the surface brightness at ''Re''. This can be confirmed by noting : \int^_0 I(r)2\pi r dr = \frac \int^_0 I(r)2\pi r dr . de Vaucouleurs model is a special case of Sersic's model, with a Sersic index of n=4. A number of (internal) density profiles that approximately reproduce de Vaucouleurs's law after projection onto the plane of the sky include Jaffe's model and Dehnen's model. The model is named after Gérard de Vaucouleurs Gérard Henri de Vauco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Chalonge
Daniel Chalonge (January 21, 1895 – November 28, 1977) was a French astronomer and astrophysicist. He was born in Grenoble and studied in Paris under Charles Fabry. Chalonge worked as an astronomer at the Observatoire de Paris, the Observatoire d'Haute Provence and the Swiss Jungfraujoch Scientific Station. One of the founders of the Institut d'astrophysique de Paris, his studies included the stellar spectrum of hydrogen, stellar photometry and classification, and measurement of the ozone layer. During the Nazi occupation of France, Chalogne assumed the position of director of the Institut d'astrophysique de Paris after the previous director, Henri Mineur, was arrested by the Gestapo. Chalonge developed a microphotometer, which was subsequently named after him. Between 1936 and 1982 he authored (or co-authored) over 90 scientific papers. Chalonge died in Paris, survived by his wife and two daughters, Karen and Sonia. Awards and honors * Janssen Medal from the French Academy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
