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751 Faïna
751 Faïna ('' prov. designation:'' ''or'' ) is a very large background asteroid from the central regions of the asteroid belt, approximately in diameter. It was discovered on 28 April 1913, by Russian astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. The elongated C-type asteroid (Ch) has a rotation period of 23.7 hours. It was named after Faina Mikhajlovna Neujmina, colleague and first wife of the discoverer. Orbit and classification Located close to the region of the stony Eunomia family (), ''Faïna'' is a non-family asteroid of the main belt's background population when applying the modern synthetic hierarchical clustering method (HCM) by Nesvorný as well as Milani and Knežević (AstDys). However, in the 1995 HCM-analysis by Zappalà, ''Faïna'' is the parent body of the tiny Faïna family, which is not recognized by modern analysis. The HCM-method is based on an object's proper orbital elements to group asteroids into families. ''Fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grigory Neujmin
Grigory Nikolayevich Neujmin (russian: Григорий Николаевич Неуймин; – 17 December 1946) was a Georgian–Russian astronomer, native of Tbilisi in Georgia, and a discoverer of numerous minor planets as well as 6 periodic and a hyperbolic comet at the Pulkovo and Simeiz Observatories during the first half of the 20th century. Discoveries The Minor Planet Center credits his discoveries under the name "G. N. Neujmin", and his surname appears this way in the literature. However, the modern English transliteration of his name would be Neuymin. Neujmin is credited with the discovery of 74 asteroids, and notably 951 Gaspra and 762 Pulcova. He also discovered and co-discovered 6 Jupiter-family comets, namely 25D/Neujmin, 28P/Neujmin, 42P/Neujmin, 57P/du Toit-Neujmin-Delporte (including fragment A) and 58P/Jackson–Neujmin, as well as C/1914 M1 (Neujmin), a hyperbolic comet. Awards and honors He received the Order of the Red Banner of Labour on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the background stars, measured in sidereal time. The other type of commonly used rotation period is the object's synodic rotation period (or ''solar day''), measured in solar time, which may differ by a fraction of a rotation or more than one rotation to accommodate the portion of the object's orbital period during one day. Measuring rotation For solid objects, such as rocky planets and asteroids, the rotation period is a single value. For gaseous or fluid bodies, such as stars and gas giants, the period of rotation varies from the object's equator to its pole due to a phenomenon called differential rotation. Typically, the stated rotation period for a gas giant (such as Jupiter, Saturn, Uranus, Neptune) is its internal rotation period, as d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Sun's apparent motion The ecliptic is the apparent path of the Sun throughout the course of a year. Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth did not orbit; a day on Earth is therefore 24 hours ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Eccentricity
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] |
Semi-major 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proper Orbital Elements
__NOTOC__ The proper orbital elements or proper elements of an orbit are constants of motion of an object in space that remain practically unchanged over an astronomically long timescale. The term is usually used to describe the three quantities: *''proper semimajor axis'' (''ap''), *''proper eccentricity'' (''ep''), and *''proper inclination'' (''ip''). The proper elements can be contrasted with the osculating Keplerian orbital elements observed at a particular time or epoch, such as the semi-major axis, eccentricity, and inclination. Those osculating elements change in a quasi-periodic and (in principle) predictable manner due to such effects as perturbations from planets or other bodies, and precession (e.g. perihelion precession). In the Solar System, such changes usually occur on timescales of thousands of years, while proper elements are meant to be practically constant over at least tens of millions of years. For most bodies, the osculating elements are relatively close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vincenzo Zappalà
Vincenzo Zappalà (born 1945) is an Italian astronomer and discoverer of several main-belt asteroids. He is credited by the Minor Planet Center with the discovered of 9 minor planets. All of his discoveries he made at ESO's Chilean La Silla Observatory in 1984, with the exception of 17357 Lucataliano, which he discovered at Mount Stromlo Observatory in 1978. He has also been a long-term astronomer at the Observatory of Turin in Pino Torinese. Awards and honors The main-belt asteroid 2813 Zappalà, discovered by American astronomer Edward Bowell at the U.S. Anderson Mesa Station in 1981, is named in his honour. List of discovered minor planets See also * * Zoran Knežević (astronomer) Zoran Knežević ( sr-cyr, Зоран Кнежевић, born 23 August 1949 in Osijek) is a Serbian astronomer, who has been publishing since 1982. His major scientific contributions are in the field of movement of small Solar System bodies, thei ... References Externa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoran Knežević (astronomer)
Zoran Knežević ( sr-cyr, Зоран Кнежевић, born 23 August 1949 in Osijek) is a Serbian astronomer, who has been publishing since 1982. His major scientific contributions are in the field of movement of small Solar System bodies, their proper elements and perturbations, as well as the identification and evolution of asteroid families. As of 2002, he is the director of Astronomical Observatory of Belgrade and the president of Serbian National Astronomy Committee. Awards and honors Asteroid 3900 Knežević, discovered by Edward Bowell, is named after him. The official naming citation was published by the Minor Planet Center on 23 December 1988 (). See also * * Vincenzo Zappalà Vincenzo Zappalà (born 1945) is an Italian astronomer and discoverer of several main-belt asteroids. He is credited by the Minor Planet Center with the discovered of 9 minor planets. All of his discoveries he made at ESO's Chilean La Silla Ob ... References External links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrea Milani (mathematician)
Andrea Milani Comparetti (Florence, 19 June 1948 – Pisa, 28 November 2018) was an Italian mathematician and astronomer, based at the University of Pisa. Biography Andrea Milani Comparetti was born in Florence, in 1948. His father, Adriano Milani Comparetti, was a pioneer in child neuro-psychiatric rehabilitation and his uncle was Don Lorenzo Milani. In 1970 he graduated in Mathematics at the University of Milan and later he studied at the Scuola Normale Superiore di Pisa. He then became a Full Professor of Mathematical Physics at the Department of Mathematics of the University of Pisa. He died on November 28, 2018, for a sudden illness, causing a deep loss in the scientific community. Career His areas of research included the N-body problem, the stability of the Solar System, asteroid dynamics, asteroid families, satellite geodesy, planetary exploration, orbit determination and asteroid impact risk assessment. In his brilliant career he pioneered most of the previous topics. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Nesvorný
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". was, according to the Hebrew Bible, the third king of the United Kingdom of Israel. In the Books of Samuel, he is described as a young shepherd and harpist who gains fame by slaying Goliath, a champion of the Philistines, in southern Canaan. David becomes a favourite of Saul, the first king of Israel; he also forges a notably close friendship with Jonathan, a son of Saul. However, under the paranoia that David is seeking to usurp the throne, Saul attempts to kill David, forcing the latter to go into hiding and effectively operate as a fugitive for several years. After Saul and Jonathan are both killed in battle against the Philistines, a 30-year-old David is anointed king over all of Israel and Judah. Following his rise to power, David c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchical Clustering Method
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] |
