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Gefion Family
The Gefion family (FIN: 516; adj. ''Gefionian''; also known as Ceres family and Minerva family) is an asteroid family located in the intermediate asteroid belt between 2.74 and 2.82 AU at inclinations of 7.4° to 10.5 °. The family of S-type asteroids is named after 1272 Gefion and consists of more than 2,500 known members. It had previously been known as the Ceres family. It is still known as Minerva family, named after then thought parent body 93 Minerva, until it was identified to be an interloper into its own family. Properties The members have proper orbital elements in the approximate ranges At the present epoch, the range of osculating orbital elements of these core members is The namesake is 1272 Gefion. The family is fairly large, e.g. the Zappala 1995 analysis found about a hundred core members. A search of a recent proper element database found 766 objects (about 0.8% of the total) lying within the region defined by the first table above. 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family Identification Number
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An asteroid family is a more specific term than asteroid group whose members, while sharing some broad orbital characteristics, may be otherwise unrelated to each other. General properties Large prominent families contain several hundred recognized asteroids (and many more smaller objects which may be either not-yet-analyzed, or not-yet-discovered). Small, compact families may have only about ten identified members. About 33% to 35% of asteroids in the main belt are family members. There are about 20 to 30 reliably recognized families, with several tens of less certain groupings. Most asteroid families are found in the main asteroid belt, although several family-like groups such as the Pallas family, Hungaria family, and the Phocaea fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum ( perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semimajor Axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longest semidiameter or one half of the major axis, and thus runs from the centre, through a focus, and to the perimeter. The semi-minor axis (minor semiaxis) of an ellipse or hyperbola is a line segment that is at right angles with the semi-major axis and has one end at the center of the conic section. For the special case of a circle, the lengths of the semi-axes are both equal to the radius of the circle. The length of the semi-major axis of an ellipse is related to the semi-minor axis's length through the eccentricity and the semi-latus rectum \ell, as follows: The semi-major axis of a hyperbola is, depending on the convention, plus or minus one half of the distance between the two branches. Thus it is the distance from the cen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2507 Bobone
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. It has attained significance throughout history in part because typical humans have five digits on each hand. In mathematics 5 is the third smallest prime number, and the second super-prime. It is the first safe prime, the first good prime, the first balanced prime, and the first of three known Wilson primes. Five is the second Fermat prime and the third Mersenne prime exponent, as well as the third Catalan number, and the third Sophie Germain prime. Notably, 5 is equal to the sum of the ''only'' consecutive primes, 2 + 3, and is the only number that is part of more than one pair of twin primes, ( 3, 5) and (5, 7). It is also a sexy prime with the fifth prime number and first prime repunit, 11. Five is the third factorial prime, an alternating factorial, and an Eisenstein prime with no imaginary part and real part of the form 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
374 Burgundia
Burgundia (minor planet designation: 374 Burgundia) is a typical main belt asteroid that was discovered by Auguste Charlois on 18 September 1893 in Nice. It was named for the former French region of Burgundy. It is one of seven of Charlois's discoveries that was expressly named by the Astromomisches Rechen-Institut (Astronomical Calculation Institute). Burgundia was long thought to be a member of the now defunct Ceres asteroid family, but it was found to be an unrelated interloper in that group based on its non-matching composition.Cellino, A . et al. "Spectroscopic Properties of Asteroid Families", in ''Asteroids III'', University of Arizona Press, pp. 633-643 (2002). References External links * * Background asteroids Burgundia Burgundia Burgundia ( minor planet designation: 374 Burgundia) is a typical main belt asteroid that was discovered by Auguste Charlois on 18 September 1893 in Nice. It was named for the former French region of Burgundy. It is one of seven o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
255 Oppavia
Oppavia (minor planet designation: 255 Oppavia) is a sizeable Main belt asteroid. It was discovered by Austrian astronomer Johann Palisa on 31 March 1886 in Vienna and was named after Opava, a town in the Czech Republic, then part of Austria-Hungary, where Palisa was born. It is orbiting the Sun at a distance of with an orbital eccentricity (ovalness) of 0.077 and a period of . The orbital plane is inclined by an angle of 9.47° to the plane of the ecliptic. Photometric observations made during 2013 indicate a synodic rotation period of with an amplitude of 0.16 in magnitude. The unusual light curve shows three uneven minima and maxima per cycle. In 1995, 255 Oppavia was suggested as a peripheral member of the now defunct Ceres asteroid family, but was found to be an unrelated interloper on the basis of its non-matching spectral type. It classified as a dark X-type asteroid in the Tholen taxonomy. References External links The Asteroid Orbital Elements Database [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Spectral Types
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated, the surface and internal compositions are presumably similar, while large bodies such as Ceres and Vesta are known to have internal structure. Over the years, there has been a number of surveys that resulted in a set of different taxonomic systems such as the Tholen, SMASS and Bus–DeMeo classifications. Taxonomic systems In 1975, astronomers Clark R. Chapman, David Morrison, and Ben Zellner developed a simple taxonomic system for asteroids based on color, albedo, and spectral shape. The three categories were labelled " C" for dark carbonaceous objects, " S" for stony (silicaceous) objects, and "U" for those that did not fit into either C or S. This basic division of asteroid spectra has since been expanded and clarified.Thoma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1 Ceres
Ceres (; minor-planet designation: 1 Ceres) is a dwarf planet in the asteroid belt between the orbits of Mars and Jupiter. It was the first asteroid discovered, on 1 January 1801, by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planetthe only one always inside Neptune's orbit. Ceres's small size means that even at its brightest, it is too dim to be seen by the naked eye, except under extremely dark skies. Its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition (when it is closest to Earth) once every 15- to 16-month synodic period. As a result, its surface features are barely visible even with the most powerful telescopes, and little was known about it until the robotic NASA spacecraft ''Dawn'' approached Ceres for its orbital mission in 2015. ''Dawn'' found Ceres's surface to be a mixture of water ice, and hydrated minerals such as carbonates and clay. Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2911 Miahelena
911 or 9/11 may refer to: Dates * AD 911 * 911 BC * September 11 ** September 11 attacks, 9/11, the September 11 attacks of 2001 ** 11 de Septiembre, Chilean coup d'état in 1973 that outed the democratically elected Salvador Allende * November 9 Numbers * 911 (number) * 9-1-1, an emergency telephone number in North America * 9-1-1 (Philippines), an emergency telephone number in the Philippines Film * ''9/11: The Twin Towers'', a 2006 documentary special about the 9/11 attacks * 9/11 (2002 film), ''9/11'' (2002 film), a documentary about the 9/11 attacks * 9/11 (2017 film), ''9/11'' (2017 film), a drama film about the 9/11 attacks * ''Reno 911!: Miami,'' a 2007 cop comedy movie based on the Reno 911! series Literature * 9-11 (Noam Chomsky), ''9-11'' (Noam Chomsky), a collection of essays by and interviews with Noam Chomsky * ''9-11: Artists Respond, Volume One'', a benefit comic published by Dark Horse Comics, Chaos! Comics, and Image Comics * ''9-11: Emergency Relief'', a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2631 Zhejiang
__NOTOC__ Year 631 ( DCXXXI) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. The denomination 631 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Byzantine Empire * Emperor Heraclius appoints Cyrus, patriarch of Alexandria, with power to act as viceroy ('' dioikesis'') of Egypt. He begins a 10-year persecution against the non-Chalcedonian Coptic Christians. Europe * Battle of Wogastisburg: The Slavs under King Samo defeat the Austrasian Franks, in a three-day battle near Trenčín (modern Slovakia). King Dagobert I is forced to retreat; the Franks with their allies are slaughtered. Samo invades Thuringia and undertakes looting raids. * King Suintila is overthrown after a 10-year reign by his son Sisenand, with the aid of Dagobert I. The Visigothic nobles offer him a 500-pound plate made of pure gold. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1272 Gefion
1272 Gefion, provisional designation , is a stony asteroid and parent body of the Gefion family from the central region of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 10 October 1931, by astronomer Karl Reinmuth at the Heidelberg Observatory in Germany. The asteroid was named after Gefjon from Norse mythology. Orbit and classification ''Gefion'' is the namesake and parent body of the Gefion family (), a large family of stony asteroids in the intermediate main belt. The family is also a suspected source of the L chondrites, common group of meteorites. It orbits the Sun in the central main-belt at a distance of 2.4–3.2 AU once every 4 years and 8 months (1,697 days; semi-major axis of 2.78 AU). Its orbit has an eccentricity of 0.15 and an inclination of 8 ° with respect to the ecliptic. The asteroid was first identified as at Heidelberg in September 1917. The body's observation arc begins at Heidelberg, six days after its offici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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