|
1313 Berna
1313 Berna, provisional designation , is a background asteroid and synchronous binary system from the Eunomian region in the central asteroid belt, approximately in diameter. It was discovered on 24 August 1933, by Belgian astronomer Sylvain Arend at the Uccle Observatory in Belgium. The assumed S-type asteroid has a longer-than average rotation period of 25.5 hours and is likely elongated in shape. It was named for the Swiss capital of Bern. The discovery of an 11-kilometer-sized companion was announced in February 2004. Orbit and classification According to modern HCM-analyses by Nesvorný, as well as by Milani and Knežević, ''Berna'' is a non-family asteroid from the main belt's background population. Based on osculating Keplerian orbital elements, it is located in the region of the Eunomia family (), a prominent family of stony asteroids. It orbits the Sun in the central asteroid belt at a distance of 2.1–3.2 AU once every 4 years and 4 months (1,584 days ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sylvain Arend
Sylvain Julien Victor Arend (6 August 1902 – 18 February 1992) was a Belgian astronomer born in Robelmont, Luxembourg province, Belgium. His main interest was astrometry. Together with Georges Roland, he discovered the bright comet C/1956 R1 (Arend-Roland). He also discovered, or co-discovered, the periodic comets 49P/Arend-Rigaux and 50P/Arend, Nova Scuti 1952, and a number of asteroids, including notably the Amor asteroid 1916 Boreas and the Trojan asteroid 1583 Antilochus. He also discovered 1652 Hergé which is named after Hergé, the creator of ''The Adventures of Tintin''. The asteroid 1563 Noël is named after his son, Emanuel Arend. In 1948 Arend started together with sixteen other people the skeptic organisation Comité Para The Comité Para, in full Comité belge pour l'Analyse Critique des parasciences ("Belgian Committee for the Critical Analysis of Parasciences"), is a Francophone Belgian skeptical non-profit organisation. Founded in 1949, the Comité ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor-planet Moon
A minor-planet moon is an astronomical object that orbits a minor planet as its natural satellite. , there are 457 minor planets known or suspected to have moons. Discoveries of minor-planet moons (and binary objects, in general) are important because the determination of their orbits provides estimates on the mass and density of the primary, allowing insights into their physical properties that are generally not otherwise accessible. Several of the moons are quite large compared to their primaries: 90 Antiope, Mors–Somnus and Sila–Nunam (95%), Patroclus–Menoetius, Altjira and Lempo–Hiisi (90%, with Lempo–Paha at 50%). The largest known minor-planet moon in ''absolute'' size is Pluto's largest moon Charon, which itself has about half the diameter of Pluto. The first modern era mention of the possibility of an asteroid satellite was in connection with an occultation of the bright star Gamma Ceti by the asteroid 6 Hebe in 1977. The observer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observation Arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly used in the discovery and tracking of asteroids and comets. Arc length has the greatest influence on the accuracy of an orbit. The number and spacing of intermediate observations has a lesser effect. Short arcs A very short arc leaves a high uncertainty parameter. The object might be in one of many different orbits, at many distances from Earth. In some cases, the initial arc was too short to determine if the object was in orbit around the Earth, or orbiting out in the asteroid belt. With a 1-day observation arc, was thought to be a trans-Neptunian dwarf planet, but is now known to be a 1 km main-belt asteroid. With an observation arc of 3 days, was thought to be a Mars-crossing asteroid that could be a threat to Earth, but was later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannesburg 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 for ... [...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] |
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] |
Orbital Elements
Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same orbit, but certain schemes, each consisting of a set of six parameters, are commonly used in astronomy and orbital mechanics. A real orbit and its elements change over time due to gravitational perturbations by other objects and the effects of general relativity. A Kepler orbit is an idealized, mathematical approximation of the orbit at a particular time. Keplerian elements The traditional orbital elements are the six Keplerian elements, after Johannes Kepler and his laws of planetary motion. When viewed from an inertial frame, two orbiting bodies trace out distinct trajectories. Each of these trajectories has its focus at the common center of mass. When viewed from a non-inertial frame centered on one of the bodies, only the traj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
