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QS Virginis
QS Virginis (abbreviated QS Vir) is an eclipsing binary system approximately 163 light-years away from the Sun, forming a cataclysmic variable. The system comprises an eclipsing white dwarf and red dwarf that orbit each other every 3.37 hours. Variability The eclipsing binary nature of QS Virginis was discovered in 1997 during the Edinburgh-Cape Blue Object Survey for blue stellar objects in the southern hemisphere. Possible third body In 2009 the discovery of an extrasolar planet in orbit around the binary star was announced, detected by variations in the timings of the eclipses of the two stars. The planet was announced to have a minimum mass 6.4 times the mass of Jupiter, in an elliptical orbit 4.2 Astronomical Units away from binary. Subsequent observations revealed that the timings were not following the pattern predicted by the planetary model. While the observed variations in eclipse times may be caused by a third body, the best fit model orbit is for an object ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Mass
In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars and binary systems, nebulae, and black holes. Minimum mass is a widely cited statistic for extrasolar planets detected by the radial velocity method or Doppler spectroscopy, and is determined using the binary mass function. This method reveals planets by measuring changes in the movement of stars in the line-of-sight, so the real orbital inclinations and true masses of the planets are generally unknown. This is a result of sin ''i'' degeneracy. If inclination ''i'' can be determined, the true mass can be obtained from the calculated minimum mass using the following relationship: M_\text = \frac Exoplanets Orientation of the transit to Earth Most stars will not have their planets lined up and orientated so that they eclipse over the center of the star and give the viewer on earth a perfect transit. It is for this reason that when we often are only able to extrapolat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dwarfs
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf. The nearest known white dwarf is at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name ''white dwarf'' was coined by Willem Luyten in 1922. White dwarfs are thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the other stars in the Milky Way. After the hydrogen- fusing period of a main-sequence star of low or medium mass ends, such a star will expand to a red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objects With Variable Star Designations
Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an aim, target, or objective * Object (grammar), a sentence element, such as a direct object or an indirect object Science, technology, and mathematics Computing * 3D model, a representation of a physical object * Object (computer science), a language mechanism for binding data with methods that operate on that data ** Object-orientation, in which concepts are represented as objects *** Object-oriented programming (OOP), in which an object is an instance of a class or array ** Object (IBM i), the fundamental unit of data storage in the IBM i operating system * Object (image processing), a portion of an image interpreted as a unit * Object file, the output of a compiler or other translator program (also known as "object code") * Object, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipsing Binaries
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, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Extrasolar Planets
These are lists of exoplanets. Most of these were discovered by the Kepler space telescope. There are an additional 2,054 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 978 from its " Second Light" mission and 4,081 from the Transiting Exoplanet Survey Satellite (TESS) mission. For yearly lists on physical, orbital and other properties, as well as on discovery circumstances and other aspects, ''see ''. Nomenclature Methods of detection Specific exoplanet lists Lists of exoplanets *List of directly imaged exoplanets * List of exoplanets discovered before 2000 () * List of exoplanets discovered between 2000–2009 () * List of exoplanets discovered in 2010 () * List of exoplanets discovered in 2011 () *List of exoplanets discovered in 2012 () * List of exoplanets discovered in 2013 () * List of exoplanets discovered in 2014 () *List of exoplanets discovered in 2015 () *List of exoplanets discovered in 2016 () *List of exoplanets discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NSVS 14256825
NSVS 14256825, also known as V1828 Aquilae, is an eclipsing binary system (of the Algol type) in the constellation of Aquila. The system comprises a subdwarf OB star and red dwarf star. The two stars orbit each other every 2.648976 hours. Based on the stellar parallax of the system, observed by ''Gaia'', the system is located approximately 2,700 light-years (840 parsecs) away. Nomenclature The system is most commonly referred to using its designation from the Northern Sky Variability Survey (NSVS), a survey of stars with apparent magnitudes between 8 and 15.5. It also has a variable star designation, V1828 Aquilae. Eclipse timing variations NSVS 14256825 has been extremely well-studied using photometry, but the resulting models often contradict each other, even with similar statistical significance, or with data that are collected later. Many studies have found that this system exhibits eclipse timing variations (ETVs) that are significant, cyclic and not explai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DP Leonis
DP Leonis (abbreviated DP Leo) is a binary star system in the equatorial constellation of Leo. It is a variable star that ranges in apparent visual magnitude from 17.5 down to 19. The system is located at a distance of approximately 990 light-years from the Sun based on parallax. It is a cataclysmic variable star of the '' AM Herculis''-type also known as '' polars''. The system comprises an eclipsing white dwarf and red dwarf in tight orbit (nearly 1.5 hours) and an extrasolar planet. This eclipsing variable was discovered by P. Biermann and associates in 1982 as the optical counterpart to the EINSTEIN X-ray source E1114+182. Planetary system In 2010, Qian ''et al.'' announced the detection of a third body of planetary mass around the eclipsing binary system. The presence of a third body had already been suspected in 2002. The object is roughly 6 times more massive than Jupiter and is located 8.6 AU from the binary. See also * NN Serpentis * QS Virg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CM Draconis
CM Draconis (GJ 630.1A) is an eclipsing binary system approximately 47 light-years away in the constellation of Draco (the Dragon). The system consists of two nearly identical red dwarf stars located in the constellation Draco. The two stars orbit each other with a period of 1.27 days with a separation of 2.7 million kilometres (0.018 AU). Along with two stars in the triple system KOI 126, the stars in CM Draconis are the lightest stars with precisely measured masses and radii. Consequently, the system plays an important role in testing stellar structure models for very low mass stars. These comparisons find that models underpredict the stellar radii by approximately 5%. This is attributed to consequences of the stars' strong magnetic activity. According to the system's entry in the Combined General Catalogue of Variable Stars, at least one of the components is a flare star and at least one is a BY Draconis variable. The white dwarf star GJ 630.1B, located 25.7 arcs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NN Serpentis
NN Serpentis (abbreviated NN Ser) is an eclipsing post-common envelope binary system approximately 1670 light-years away. The system comprises an eclipsing white dwarf and red dwarf. The two stars orbit each other every 0.13 days. Planetary system A planetary system has been inferred to exist around NN Ser by several teams. All of these teams rely on the fact that Earth sits in the same plane as the NN Serpentis binary star system, so humans can see the larger red dwarf eclipse the white dwarf every 0.13 days. Astronomers are then able to use these frequent eclipses to spot a pattern of small but significant irregularities in the orbit of stars, which could be attributed to the presence and gravitational influence of circumbinary planets. Chen (2009) used these "eclipse timing variations" to suggesting a putative orbital period spanning between 30 and 285 years and a minimum mass between 0.0043 and 0.18 Solar masses. In late 2009, Qian estimated a minimum mass of 10.7 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HW Virginis
HW Virginis, abbreviated HW Vir, is an eclipsing binary system (of the Algol type), approximately 563 light-years away based on the parallax measured by the Gaia spacecraft, in the constellation of Virgo. The system comprises an eclipsing B-type subdwarf star and red dwarf star. The two stars orbit each other every 0.116795 days. Eclipse timing variations Based on variations in the timing of the system's eclipses, in 2008 it was claimed that two giant planets were in orbit around the binary, with masses of 8.47 and 19.2 times the mass of Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandt ... orbiting with periods of 9.1 and 15.8 years respectively. The proposed system was later shown to be extremely unstable, with mean lifetimes less than 1000 years in the param ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algol
ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages originally developed in 1958. ALGOL heavily influenced many other languages and was the standard method for algorithm description used by the Association for Computing Machinery (ACM) in textbooks and academic sources for more than thirty years. In the sense that the syntax of most modern languages is "Algol-like", it was arguably more influential than three other high-level programming languages among which it was roughly contemporary: FORTRAN, Lisp, and COBOL. It was designed to avoid some of the perceived problems with FORTRAN and eventually gave rise to many other programming languages, including PL/I, Simula, BCPL, B, Pascal, and C. ALGOL introduced code blocks and the begin...end pairs for delimiting them. It was also the first language implementing nested function definitions with lexical scope. Moreover, it was the first programming language which gave detailed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
