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Phocaea Family
The Phocaea family ( ; adj. ''Phocaean''; ) is a collisional family of asteroids located between 2.25 and 2.5 AU in the inner region of the asteroid belt. Phocaea asteroids are of stony S-type composition and have orbits with eccentricities greater than 0.1 and inclinations between 18 and 32 °. The family has an estimated age of 2.2 billion years and derives its name from its most massive member, 25 Phocaea which is about 75 km in diameter. Several Phocaean asteroids are also Mars-crossers. Phocaea family region The Phocaea family region contains other collisional families such as the recently identified carbonaceous, Tamara family, named after its potentially largest member 326 Tamara. The family has an estimated age of 264 million years. Several clumps around 290 Bruna (Bruna family), 1192 Prisma and 6246 Komurotoru 6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number. In mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FIN Tbl
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 family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-type Asteroid
C-type (carbonaceous) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks and minerals. Their density averages at about . They occur most frequently at the outer edge of the asteroid belt, 3.5 astronomical units (AU) from the Sun, where 80% of the asteroids are of this type, whereas only 40% of asteroids at 2 AU from the Sun are C-type. The proportion of C-types may actually be greater than this, because C-types are much darker (and therefore less detectable) than most other asteroid types except for D-types and others that are mostly at the extreme outer edge of the asteroid belt. Characteristics Asteroids of this class have spectra very similar to those of carbonaceous chondrite meteorites (types CI and CM). The latter are very close in chemical composition to the Sun and the primitive solar nebula minus h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1090 Sumida
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 is the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
25 Phocaea
Phocaea (minor planet designation: 25 Phocaea) is a stony asteroid from the inner regions of the asteroid belt, approximately 75 kilometers in diameter. It is the parent body of the Phocaea family. Discovered by Jean Chacornac in 1853, it was named after the ancient Greek city of Phocaea. Discovery and naming ''Phocaea'' was discovered on 6 April 1853, by French astronomer Jean Chacornac at Marseille Observatory in southern France. It was his first asteroid discovery out of a total of six. The asteroid was named after the ancient Ionian Greek city of Phocaea, modern-day Foça in Turkey, where the founders of Marseille came from. The naming was proposed by French astronomer Benjamin Valz. Classification and orbit ''Phocaea'' is the parent body and namesake of the Phocaea family (), a large asteroid family of stony asteroids in the inner main belt. It orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 9 months (1,358 days). Its orbit has an eccentri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentricity (orbit)
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * circular orbit: ''e'' = 0 * elliptic orbit: 0 < ''e'' < 1 * [...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 center t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6246 Komurotoru
6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number. In mathematics Six is the smallest positive integer which is neither a square number nor a prime number; it is the second smallest composite number, behind 4; its proper divisors are , and . Since 6 equals the sum of its proper divisors, it is a perfect number; 6 is the smallest of the perfect numbers. It is also the smallest Granville number, or \mathcal-perfect number. As a perfect number: *6 is related to the Mersenne prime 3, since . (The next perfect number is 28.) *6 is the only even perfect number that is not the sum of successive odd cubes. *6 is the root of the 6-aliquot tree, and is itself the aliquot sum of only one other number; the square number, . Six is the only number that is both the sum and the product of three consecutive positive numbers. Unrelated to 6's being a perfect number, a Golomb ruler of length 6 is a "perfect ruler". Six is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1192 Prisma
1192 Prisma, provisional designation , is an elongated Phocaea asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by German astronomer Friedrich Schwassmann at the Bergedorf Observatory in Hamburg on 17 March 1931. The asteroid was named after the ''Bergedorf Spectral Catalogue'', an astronomical catalog. Classification and orbit ''Prisma'' is a member of the Phocaea family (), a prominent family of S-type asteroids with their largest members being 25 Phocaea and 587 Hypsipyle. There are many Mars-crossers among this family of relatively eccentric inner main-belt asteroids . The asteroid orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 8 months (1,329 days). Its orbit has an eccentricity of 0.26 and an inclination of 24 ° with respect to the ecliptic. The body's observation arc begins at Bergedorf, one week after its official discovery observation. Physical characteristics R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
290 Bruna
Bruna (minor planet designation: 290 Bruna) is a main belt asteroid that was discovered on 20 March 1890 by Johann Palisa, an Austrian astronomer at the Vienna Observatory. Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico, during 2008 gave a light curve with a period of 13.807 ± 0.001 hours and a brightness variation of 0.54 ± 0.04 in magnitude. Changes in the brightness of the minimum with phase angle is attributed to changes in the shadows across surface features. It was named by Hofrath August Bielsa for Brünn, now Brno Brno ( , ; german: Brünn ) is a city in the South Moravian Region of the Czech Republic. Located at the confluence of the Svitava and Svratka rivers, Brno has about 380,000 inhabitants, making it the second-largest city in the Czech Republic ..., Czech Republic, Bielsa's home town. References External links * * Phocaea asteroids Bruna Bruna 18900320 {{Beltasteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
326 Tamara
Tamara (minor planet designation: 326 Tamara) is a large Main belt asteroid. It is classified as a C-type asteroid and is probably composed of carbonaceous material. It is the largest member and namesake of the Tamara Family, a 264 million year-old sub-family of the collisional Phocaea family. It was discovered by Johann Palisa on 19 March 1892 in Vienna and is named after Tamar of Georgia. Name was given by Grand Duke George Alexandrovich of Russia Grand Duke George Alexandrovich of Russia ( 1871 – 1899) was the third son of Emperor Alexander III and Empress Maria of Russia. Childhood George was named after his uncle, King George I of Greece. He was brought up in a spartan fashion wi .... References External links * * 000326 Discoveries by Johann Palisa Named minor planets 000326 18920319 {{C-beltasteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars-crosser
A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for instance the JPL Small-Body Database (JPL SBDB), only list asteroids with a perihelion greater than 1.3 AU as Mars-crossers. An asteroid with a perihelion less than this is classed as a near-Earth object even though it is crossing the orbit of Mars as well as crossing (or coming near to) that of Earth. Nevertheless, these objects are listed on this page. A grazer is an object with a perihelion below the aphelion of Mars (1.67 AU) but above the Martian perihelion (1.38 AU). The JPL SBDB lists 13,500 Mars-crossing asteroids. Only 18 MCAs are brighter than absolute magnitude (H) 12.5, which typically makes these asteroids with H<12.5 more than 13 km in diameter depending on the |
Asteroid Family
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 family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
