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ʻOumuamua
Oumuamua is the first known interstellar object detected passing through the Solar System. Naming of comets#Current system, Formally designated 1I/2017 U1, it was discovered by Robert Weryk using the Pan-STARRS telescope at Haleakalā Observatory, Hawaii, on 19 October 2017, approximately 40 days after it passed its Apsis#Perihelion and aphelion, closest point to the Sun on 9 September. When it was first observed, it was about from Earth (about 85 times as far away as the Moon), and already heading away from the Sun. Oumuamua is a small object estimated to be between long, with its width and thickness both estimated to range between . It has a red color, similar to objects in the outer Solar System. Despite its close approach to the Sun, Oumuamua showed no signs of having a Coma (cometary), coma. It has exhibited Gravitational acceleration, nongravitational acceleration, potentially due to outgassing or a push from solar radiation pressure. Nonetheless, the object could be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstellar Object
An interstellar object is an astronomical object (such as an asteroid, a comet, or a rogue planet, but not a star) in interstellar space that is not gravitationally bound to a star. This term can also be applied to an object that is on an interstellar trajectory but is temporarily passing close to a star, such as certain asteroids and comets (including exocomets). In the latter case, the object may be called an interstellar interloper. The first interstellar objects discovered were rogue planets, planets ejected from their original stellar system (e.g., OTS 44 or Cha 110913−773444), though they are difficult to distinguish from sub-brown dwarfs, planet-mass objects that formed in interstellar space as stars do. The first interstellar object which was discovered traveling through our Solar System was 1I/ʻOumuamua in 2017. The second was 2I/Borisov in 2019. They both possess significant hyperbolic excess velocity, indicating they did not originate in the Solar System. Earlier, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstellar Object
An interstellar object is an astronomical object (such as an asteroid, a comet, or a rogue planet, but not a star) in interstellar space that is not gravitationally bound to a star. This term can also be applied to an object that is on an interstellar trajectory but is temporarily passing close to a star, such as certain asteroids and comets (including exocomets). In the latter case, the object may be called an interstellar interloper. The first interstellar objects discovered were rogue planets, planets ejected from their original stellar system (e.g., OTS 44 or Cha 110913−773444), though they are difficult to distinguish from sub-brown dwarfs, planet-mass objects that formed in interstellar space as stars do. The first interstellar object which was discovered traveling through our Solar System was 1I/ʻOumuamua in 2017. The second was 2I/Borisov in 2019. They both possess significant hyperbolic excess velocity, indicating they did not originate in the Solar System. Earlier, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperbolic Asteroid
A hyperbolic asteroid is any sort of asteroid or non-cometary astronomical object observed to have an orbit not bound to the Sun and will have an orbital eccentricity greater than 1 when near perihelion. Unlike hyperbolic comets, they have not been seen out-gassing light elements, and therefore have no cometary coma. Most of these objects will only be weakly hyperbolic and will not be of interstellar origin. Orbit explanation The planets and most satellites of the solar system revolve in an almost circular motion – called an elliptical orbit – around the Sun or their parent planet, so their orbital eccentricity is generally much closer to 0 than to 1. In mathematics, by definition, an eccentricity (''e'') of 1 characterizes a parabola, and ''e'' > 1, a hyperbola. Some comets are on parabolic and hyperbolic orbits. This means that these hyperbolic asteroids all have an orbital eccentricity greater than 1. Known hyperbolic asteroids So far most hyperbolic asteroids discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Weryk
Robert J. Weryk (born 1981) is a Canadian physicist and astronomer. He currently works at the University of Hawaii at Manoa where he discovered the first known interstellar object, ʻOumuamua. He has also published numerous articles on meteors A meteoroid () is a small rocky or metallic body in outer space. Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as mi ... and other astronomical topics. References 1981 births Living people Canadian physicists 21st-century Canadian astronomers University of Hawaiʻi at Mānoa faculty {{astronomer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pan-STARRS
The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1; List of observatory codes, obs. code: IAU code#F51, F51 and Pan-STARRS2 obs. code: IAU code#F52, F52) located at Haleakala Observatory, Hawaii, US, consists of astronomical cameras, telescopes and a computing facility that is Astronomical survey, surveying the sky for moving or variable objects on a continual basis, and also producing accurate astrometry and photometry (astronomy), photometry of already-detected objects. In January 2019 the second Pan-STARRS data release was announced. At 1.6 petabytes, it is the largest volume of astronomical data ever released. Description The Pan-STARRS Project is a collaboration between the University of Hawaii Institute for Astronomy (Hawaii), Institute for Astronomy, MIT Lincoln Laboratory, MHPCC#Maui High Performance Computing Center (MHPCC), Maui High Performance Computing Center and Science Applications International Corporation. Telescope construction was funded b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naming Of Comets
Comets have been observed for over 2,000 years. During that time, several different systems have been used to assign names to each comet, and as a result many comets have more than one name. The simplest system names comets after the year in which they were observed (e.g. the Great Comet of 1680). Later a convention arose of using the names of people associated with the discovery (e.g. Comet Hale–Bopp) or the first detailed study (e.g. Halley's Comet) of each comet. During the twentieth century, improvements in technology and dedicated searches led to a massive increase in the number of comet discoveries, which led to the creation of a numeric designation scheme. The original scheme assigned codes in the order that comets passed perihelion (e.g. Comet 1970 II). This scheme operated until 1994, when continued increases in the numbers of comets found each year resulted in the creation of a new scheme. This system, which is still in operation, assigns a code based on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrasolar
An ''extrasolar object'' ({{ety, la, extra, outside or beyond, , solaris, of the Sun) is an astronomical object that exists outside the Solar System. It is not applied to stars, or any other celestial object that is larger than a star or the Solar System, such as a galaxy. The terms for extrasolar examples of Solar System bodies are: * Extrasolar planet, also called an "exoplanet" * Extrasolar moon, also called an "exomoon" * Exocomet, an extrasolar comet * Extrasolar asteroid, with one identified as of 2013, orbiting GD 61 Some Solar System object classes, such as minor planets, dwarf planets and Trans-Neptunian objects have not been detected outside the Solar System. See also * Extraterrestrial, referring to objects or phenomena existing within the Solar System, but not on Earth * Extragalactic astronomy, the study of objects outside the Milky Way Galaxy * Interstellar object, an object that has traveled through interstellar space, such as ʻOumuamua Oumuamua is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outer Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound system of the Sun and the objects that orbit it. It formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority (99.86%) of the system's mass is in the Sun, with most of the remaining mass contained in the planet Jupiter. The four inner system planets—Mercury, Venus, Earth and Mars—are terrestrial planets, being composed primarily of rock and metal. The four giant planets of the outer system are substant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exocomet
An exocomet, or extrasolar comet, is a comet outside the Solar System, which includes rogue comets and comets that orbit stars other than the Sun. The first exocomets were detected in 1987 around Beta Pictoris, a very young A-type main-sequence star. There are now (as of February 2019) a total of 27 stars around which exocomets have been observed or suspected. The majority of discovered exocometary systems (Beta Pictoris, HR 10, 51 Ophiuchi, HR 2174, HD 85905, 49 Ceti, 5 Vulpeculae, 2 Andromedae, HD 21620, Rho Virginis, HD 145964, HD 172555, Lambda Geminorum, HD 58647, Phi Geminorum, Delta Corvi, HD 109573, Phi Leonis, 35 Aquilae, HD 24966, HD 38056, HD 79469 and HD 225200) are around very young A-type stars. The relatively old shell star Phi Leonis shows evidence of exocomets in the spectrum and comet-like activity was detected around the old F2V-type star Eta Corvi. In 2018 transiting exocomets were discovered around F-type stars, using data from the Kepler space te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coma (cometary)
The coma is the nebulous envelope around the nucleus of a comet, formed when the comet passes close to the Sun on its highly elliptical orbit; as the comet warms, parts of it sublimate. This gives a comet a "fuzzy" appearance when viewed in telescopes and distinguishes it from stars. The word ''coma'' comes from the Greek "kome" (κόμη), which means "hair" and is the origin of the word ''comet'' itself. The coma is generally made of ice and comet dust. Water composes up to 90% of the volatiles that outflow from the nucleus when the comet is within 3-4 AU of the Sun. The H2O parent molecule is destroyed primarily through photodissociation and to a much smaller extent photoionization. The solar wind plays a minor role in the destruction of water compared to photochemistry. Larger dust particles are left along the comet's orbital path while smaller particles are pushed away from the Sun into the comet's tail by light pressure. On 11 August 2014, astronomers released stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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