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HE 0437-5439
HE 0437-5439 is a massive, unbound hypervelocity star (HVS), also called HVS3. It is a main sequence B-type star located in the Dorado constellation. It was discovered in 2005 with the Kueyen telescope, which is part of the European Southern Observatory's Very Large Telescope array. HE 0437-5439 is a young star, with an age of around 30 million years. The mass of the star is almost nine times greater than the mass of the Sun and the star is located 200,000 light years away in the direction of the Dorado constellation, 16 degrees northwest of the Large Magellanic Cloud (LMC) and farther away than the LMC. The star appears to be receding at an extremely high velocity of , or . At this speed, the star is no longer gravitationally bound and will leave the Milky Way galaxy system and escape into intergalactic space. It was thought to have originated in the LMC and been ejected from it soon after birth. This could happen if it originally was one of a pair of stars and if ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HE 0437-5439 HST
He or HE may refer to: Language * He (pronoun), an English pronoun * He (kana), the romanization of the Japanese kana へ * He (letter), the fifth letter of many Semitic alphabets * He (Cyrillic), a letter of the Cyrillic script called ''He'' in Ukrainian * Hebrew language (ISO 639-1 code: he) Places * He County, Anhui, China * He River, or Hejiang (贺江), a tributary of the Xi River in Guangxi and Guangdong * Hebei, abbreviated as ''HE'', a province of China (Guobiao abbreviation HE) * Hesse, abbreviated as ''HE'', a state of Germany People * He (surname), Chinese surname, sometimes transcribed Hé or Ho; includes a list of notable individuals so named * Zheng He (1371–1433), Chinese admiral * He (和) and He (合), collectively known as 和合二仙 ('' He-He er xian'', "Two immortals He"), two Taoist immortals known as the "Immortals of Harmony and Unity" * Immortal Woman He, or He Xiangu, one of the Eight Immortals of Taoism Arts, entertainment, and media * "He" (sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Kinematics
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space. Stellar kinematics encompasses the measurement of stellar velocities in the Milky Way and its satellites as well as the internal kinematics of more distant galaxies. Measurement of the kinematics of stars in different subcomponents of the Milky Way including the thin disk, the thick disk, the bulge, and the stellar halo provides important information about the formation and evolutionary history of our Galaxy. Kinematic measurements can also identify exotic phenomena such as hypervelocity stars escaping from the Milky Way, which are interpreted as the result of gravitational encounters of binary stars with the supermassive black hole at the Galactic Center. Stellar kinematics is related to but distinct from the subject of stellar dynamics, which involves the theoretical study or modeling of the motions of stars under the influence of gravity. Stellar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intergalactic Stars
An intergalactic star, also known as an intracluster star or a rogue star, is a star not gravitationally bound to any galaxy. Although a source of much discussion in the scientific community during the late 1990s, intergalactic stars are now generally thought to have originated in galaxies, like other stars, before being expelled as the result of either galaxies colliding or of a multiple-star system traveling too close to a supermassive black hole, which are found at the center of many galaxies. Collectively, intergalactic stars are referred to as the intracluster stellar population, or IC population for short, in the scientific literature. Discovery The hypothesis that stars exist only in galaxies was disproven in 1997 with the discovery of intergalactic stars. The first to be discovered were in the Virgo cluster of galaxies, where some one trillion are now surmised to exist. Formation The way these stars arise is still a mystery, but several scientifically credible hypothese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Letters
Letter, letters, or literature may refer to: Characters typeface * Letter (alphabet), a character representing one or more of the sounds used in speech; any of the symbols of an alphabet. * Letterform, the graphic form of a letter of the alphabet, either as written or in a particular type font. * Rehearsal letter in an orchestral score Communication * Letter (message), a form of written communication ** Mail * Letters, the collected correspondence of a writer or historically significant person ** Maktubat (other), the Arabic word for collected letters **Pauline epistles, addressed by St. Paul to various communities or congregations, such as "Letters to the Galatians" or "Letters to the Corinthians", and part of the canonical books of the Bible * The letter as a form of second-person literature; see Epistle ** Epistulae (Pliny) ** Epistolary novel, a long-form fiction composed of letters (epistles) * Open letter, a public letter as distinguished from private corresponde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Years
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. Defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escape Velocity
In celestial mechanics, escape velocity or escape speed is the minimum speed needed for a free, non- propelled object to escape from the gravitational influence of a primary body, thus reaching an infinite distance from it. It is typically stated as an ideal speed, ignoring atmospheric friction. Although the term "escape velocity" is common, it is more accurately described as a speed than a velocity because it is independent of direction; the escape speed increases with the mass of the primary body and decreases with the distance from the primary body. The escape speed thus depends on how far the object has already traveled, and its calculation at a given distance takes into account that without new acceleration it will slow down as it travels—due to the massive body's gravity—but it will never quite slow to a stop. A rocket, continuously accelerated by its exhaust, can escape without ever reaching escape speed, since it continues to add kinetic energy from its engine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole
A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary (topology), boundary of no escape is called the event horizon. Although it has a great effect on the fate and circumstances of an object crossing it, it has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with thermal radiation, the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Obje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star System
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough they can gravitationally distort their mutual outer stellar atmospheres. In some cases, these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
