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Comet Crommelin
Comet Crommelin, also known as Comet Pons-Coggia-Winnecke-Forbes, is a periodic comet with an orbital period of almost 28 years. It fits the classical definition of a Halley-type comet with (20 years < < 200 years). It is named after the Andrew C. D. Crommelin who calculated its orbit in 1930. It is one of only four comets not named after their discoverer(s), the other three being Comets |
Jean-Louis Pons
Jean-Louis Pons (24 December 176114 October 1831) was a French astronomer. Despite humble beginnings and being self-taught, he went on to become the greatest visual comet discoverer of all time: between 1801 and 1827 Pons discovered thirty-seven comets, more than any other person in history. Pons worked at three observatories in his career, Marseille Observatory, where he was also trained, a short-lived observatory at Royal Park La Marlia in Tuscany, and finally at an observatory in Florence. Pons's work supported some famous comet recoveries of the 19th century, including Encke's Comet and Crommelin's Comet. However, most of the comets he discovered had parabolic orbits and would not return for a time as long as several millennia. Early life Pons was born in Peyre, Hautes-Alpes, to a poor family; he received little formal education. In 1789, he began working for the Marseille Observatory as a caretaker, and gradually gained some experience in assisting the astronomers with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D/Biela
Biela's Comet or Comet Biela (official designation: 3D/Biela) was a periodic Jupiter-family comet first recorded in 1772 by Montaigne and Messier and finally identified as periodic in 1826 by Wilhelm von Biela. It was subsequently observed to split in two and has not been seen since 1852. As a result, it is currently considered to have been destroyed, although remnants appeared to have survived for some time as a meteor shower, the Andromedids. Discovery The comet was first recorded on 8 March 1772 by Jacques Leibax Montaigne; during the same apparition it was independently discovered by Charles Messier. It was also recorded in 1805 by Jean-Louis Pons, but was not recognized as the same object. After the 1805 apparition a number of attempts were made by Gauss (1806) and Bessel (1806) to calculate a definitive orbit. Gauss and Olbers both noted a similarity between the 1805 and 1772 comets but they were not able to prove a link. Confirmation as periodic It was Wilhelm von ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPL Horizons On-Line Ephemeris System
JPL Horizons On-Line Ephemeris System provides access to key Solar System data and flexible production of highly accurate ephemerides for Solar System objects. Osculating elements at a given epoch (such as produced by the JPL Small-Body Database) are always an approximation to an object's orbit (i.e. an unperturbed conic orbit or a " two-body" orbit). The real orbit (or the best approximation to such) considers perturbations by all planets, a few of the larger asteroids, a few other usually small physical forces, and requires numerical integration. Jet Propulsion Laboratory (JPL) ephemerides do not use things such as periods, eccentricities, etc. Instead, JPL integrates the equations of motion in Cartesian coordinates (x,y,z), and adjusts the initial conditions in order to fit modern, highly accurate measurements of planetary positions. Since August 2013, Horizons has been using ephemeris DE431. During the week of 12 April 2021, the Horizons ephemeris system was updated to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IAU Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function The Minor Planet Center is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids), calculating their orbits and publishing this information via the '' Minor Planet Circulars''. Under the auspices of the International Astronomical Union (IAU), it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory. The MPC runs a number of free online services for observers to assist them in observing minor planets and comets. The complete catalogue of minor planet orbits (sometimes referred to as the "Minor Planet Catalogue") may also be freely downloaded. In addition to astrometric data, the MPC colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. The word ''magnitude'' in astronomy, unless stated otherwise, usually refers to a celestial object's apparent magnitude. The magnitude scale dates back to the ancient Roman astronomer Claudius Ptolemy, whose star catalog listed stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined in a way to closely match this historical system. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to a brightness ratio of \sqrt /math>, or about 2.512. For example, a star of magnitude 2.0 is 2.512 times as bright as a star of magnitude 3.0, 6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lost Comet
A lost comet is one which was not detected during its most recent perihelion passage. This generally happens when data is insufficient to reliably calculate the comet's location or if the solar elongation is unfavorable near perihelion passage. The ''D/'' designation is used for a periodic comet that no longer exists or is deemed to have disappeared. Lost comets can be compared to lost asteroids ( lost minor planets), although calculation of comet orbits differs because of nongravitational forces, such as emission of jets of gas from the nucleus. Some astronomers have specialized in this area, such as Brian G. Marsden, who successfully predicted the 1992 return of the once-lost periodic comet Swift–Tuttle. Overview Loss There are a number of reasons why a comet might be missed by astronomers during subsequent apparitions. Firstly, cometary orbits may be perturbed by interaction with the giant planets, such as Jupiter. This, along with nongravitational forces, can result i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Union Observatory
Union Observatory also known as Johannesburg Observatory ( 078) is a defunct astronomical observatory in Johannesburg, South Africa that was operated between 1903 and 1971. It is located on Observatory Ridge, the city's highest point at 1,808 metres altitude in the suburb Observatory. The observatory and its former annex, the , are known for the discovery of 6,000 double stars and for Proxima Centauri, made by astronomer Robert Innes. At the observatory, 578 identifications of minor planet were made, a record number at the time. The Minor Planet Center credits the observatory as the site where 147 minor planets were discovered by astronomers Harry Wood, Cyril Jackson, Hendrik van Gent, Ernest Johnson, Ejnar Hertzsprung, Jacobus Bruwer and Joseph Churms ''(see )''. History The origins of the observatory began when Theodore Reunert of the South African Association for the Advancement of Science petitioned Alfred Milner Governor of the Transvaal Colony on 29 October 1902 fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Edwin Wood
Harry Edwin Wood (3 February 1881 – 27 February 1946) was an English astronomer, director of the Union Observatory in Johannesburg, and discoverer of minor planets. Wood was born in Manchester, graduating from Manchester University in 1902 with first class honours in physics, going on to gain an M.Sc in 1905. In 1906 he was appointed the Chief Assistant at the ''Transvaal Meteorological Observatory'', which soon acquired telescopes and which became known as the Union Observatory and later Republic Observatory. In 1909, he married Mary Ethel Greengrass, also a physics graduate of Manchester University. Wood served as the observatory's director from 1928 to 1941, succeeding Robert Innes. He also served as the president of the ''Astronomical Society of South Africa'' from 1929 to 1930. Wood is credited by the Minor Planet Center with the discovery of 12 numbered asteroids during 1911–1932. He died in Mortimer, near Cradock, Eastern Cape, South Africa, in 1946. The asteroid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black South Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Town
Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest (after Johannesburg). Colloquially named the ''Mother City'', it is the largest city of the Western Cape province, and is managed by the City of Cape Town metropolitan municipality. The other two capitals are Pretoria, the executive capital, located in Gauteng, where the Presidency is based, and Bloemfontein, the judicial capital in the Free State, where the Supreme Court of Appeal is located. Cape Town is ranked as a Beta world city by the Globalization and World Cities Research Network. The city is known for its harbour, for its natural setting in the Cape Floristic Region, and for landmarks such as Table Mountain and Cape Point. Cape Town is home to 66% of the Western Cape's population. In 2014, Cape Town was named the best place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander F
Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Aleksander and Aleksandr. Related names and diminutives include Iskandar, Alec, Alek, Alex, Alexandre, Aleks, Aleksa and Sander; feminine forms include Alexandra, Alexandria, and Sasha. Etymology The name ''Alexander'' originates from the (; 'defending men' or 'protector of men'). It is a compound of the verb (; 'to ward off, avert, defend') and the noun (, genitive: , ; meaning 'man'). It is an example of the widespread motif of Greek names expressing "battle-prowess", in this case the ability to withstand or push back an enemy battle line. The earliest attested form of the name, is the Mycenaean Greek feminine anthroponym , , (/ Alexandra/), written in the Linear B syllabic script. Alaksandu, alternatively called ''Alakasandu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strasbourg
Strasbourg (, , ; german: Straßburg ; gsw, label=Bas Rhin Alsatian, Strossburi , gsw, label=Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the European Parliament. Located at the border with Germany in the historic region of Alsace, it is the prefecture of the Bas-Rhin department. In 2019, the city proper had 287,228 inhabitants and both the Eurométropole de Strasbourg (Greater Strasbourg) and the Arrondissement of Strasbourg had 505,272 inhabitants. Strasbourg's metropolitan area had a population of 846,450 in 2018, making it the eighth-largest metro area in France and home to 14% of the Grand Est region's inhabitants. The transnational Eurodistrict Strasbourg-Ortenau had a population of 958,421 inhabitants. Strasbourg is one of the ''de facto'' four main capitals of the European Union (alongside Brussels, Luxembourg and Frankfurt), as it is the seat of several European insti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
