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3240 Laocoon
3240 Laocoon is a carbonaceous Jupiter trojan from the Trojan camp, approximately in diameter. It was discovered on 7 November 1978, by American astronomers Eleanor Helin and Schelte Bus at Palomar Observatory in California. The D-type asteroid belongs to the 100 largest Jupiter trojans and has a rotation period of 11.3 hours. It was named after Laocoön from Greek mythology. Classification and orbit ''Laocoon'' resides in the Trojan camp of Jupiter's Lagrangian point, which lies 60 ° behind the gas giant's orbit. It is also a non-family asteroid of the Jovian background population. It orbits the Sun at a distance of 4.6–5.9 AU once every 11 years and 12 months (4,375 days; semi-major axis of 5.23 AU). Its orbit has an eccentricity of 0.13 and an inclination of 2 ° with respect to the ecliptic. The asteroid was first observed as ' at Crimea–Nauchnij in September 1976, extending the body's observation arc by 2 years prior to its official discovery at Paloma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eleanor Helin
Eleanor Francis "Glo" Helin (née Francis, 19 November 1932 – 25 January 2009) was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory. (Some sources give her name as Eleanor Kay Helin.) Helin was a prolific discoverer of minor planets ''(see list)'' and several comets, including periodic comets 111P/Helin–Roman–Crockett, 117P/Helin–Roman–Alu and 132P/Helin–Roman–Alu. She is credited as the discoverer of the object now known as both asteroid 4015 Wilson–Harrington and comet 107P/Wilson–Harrington. Although Wilson and Harrington preceded her by some decades, their observations did not establish an orbit for the object, while her rediscovery did. Helin discovered or co-discovered 903 asteroids and several comets. Biography Helin was born an only child to Fred and Kay Francis. At the age of five, she became ill with polio, which caused her to be bed-ridden for several ... [...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] |
La Silla Observatory
La Silla Observatory is an astronomy, astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are located at the site and are partly maintained by ESO. The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO. The La Silla telescopes and instruments are located 150 km northeast of La Serena, Chile, La Serena at the outskirts of the Chilean Atacama Desert, one of the driest and most remote areas of the world. Like other observatories in this geographical area, La Silla is located far from sources of light pollution and, like the Paranal Observatory, home to the Very Large Telescope, it has one of the darkest night skies on the Earth. History Following the decision in 1963 to approve Chile as the site for the ESO observatory, scouting parties were sent to various locations to assess their suitability. The site that was decided upon was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bochum 0
Bochum ( , also , ; wep, Baukem) is a city in North Rhine-Westphalia. With a population of 364,920 (2016), is the sixth largest city (after Cologne, Düsseldorf, Dortmund, Essen and Duisburg) of the most populous German federal state of North Rhine-Westphalia and the 16th largest city of Germany. On the Ruhr Heights (''Ruhrhöhen'') hill chain, between the rivers Ruhr to the south and Emscher to the north (tributaries of the Rhine), it is the second largest city of Westphalia after Dortmund, and the fourth largest city of the Ruhr after Dortmund, Essen and Duisburg. It lies at the centre of the Ruhr, Germany's largest urban area, in the Rhine-Ruhr Metropolitan Region, and belongs to the region of Arnsberg. Bochum is the sixth largest and one of the southernmost cities in the Low German dialect area. There are nine institutions of higher education in the city, most notably the Ruhr University Bochum (''Ruhr-Universität Bochum''), one of the ten largest universities in Germany, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stefano Mottola
This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numbered minor planets are credited to 1141 astronomers and 253 observatories, telescopes or surveys ''(see )''. On how a discovery is made, ''see observations of small Solar System bodies. For a description of the tables below, see ''. Discovering astronomers }, (bio-de) , align=left , M. Matsuyama , , - id="D. Matter" , align=left , Daniel Matter , 7 , 1957–pres. , , align=left , D. Matter; amateur, (bio-it) , align=left , D. Matter , , - id="A. Maury" , align=left , Alain Maury , 9 , 1958–pres. , , align=left , A. Maury; , align=left , A. Maury , , - id="D. Mayes" , align=left , Deronda Mayes , , 1957–pres. , , align=left , D. Mayes; inferred , align=left , D. Mayes , , - id="E. Mazzoni ... [...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] |
Crimea–Nauchnij
The Crimean Astrophysical Observatory (CrAO, obs. code: 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called simply by its location and campus name, Crimea–Nauchnij, still ranks among the worldwide most prolific discovery sites for minor planets. CrAO has also been publishing the ''Bulletin of the Crimean Astrophysical Observatory'' since 1947, in English since 1977. The observatory facilities (IAU code 095) are located on territory of settlement of Nauchnyi since the mid-1950s; before that, they were further south, near Simeiz. The latter facilities still see some use, and are referred to as the Crimean Astrophysical Observatory–Simeiz (IAU code 094). Observatory leaders * 1945–1952: Grigory Shajn - head of construction, the first director of the Observatory at Nauchny. * 1952–1987: Andrei Severny. * 1987–2005: Nikolai Steshenko. * 2005 – present: Alla Rostopchina-Sha ... [...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] |
Background Asteroid
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] |
