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Galaxy X (galaxy)
Galaxy X is a postulated dark satellite dwarf galaxy of the Milky Way Galaxy. If it exists, it would be composed mostly of dark matter and interstellar gas with few stars. Its proposed location is some from the Sun, behind the disk of the Milky Way, and some in extent. Galactic coordinates would be (l= -27.4°,b=-1.08°). Discovery Observational evidence for this galaxy was presented in 2015, based on the claimed discovery of four Cepheid variable stars by Sukanya Chakrabarti (RIT) and collaborators. Search for the stars was motivated by an earlier study that linked a warp in the HI (atomic hydrogen) disk of the Milky Way Galaxy to the tidal effects of a perturbing galaxy. The unseen perturber's mass was calculated to be about 1%approximately 10 billion solar masses of that of the Milky Way, which would make it the third heaviest satellite of the Milky Way, after the Magellanic Clouds (Large Magellanic Cloud and Small Magellanic Cloud, each some 10x larger than Galaxy X ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Galaxy
A dark galaxy is a hypothesized galaxy with no, or very few, stars. They received their name because they have no visible stars, but may be detectable if they contain significant amounts of gas. Astronomers have long theorized the existence of dark galaxies, but there are no confirmed examples to date. Dark galaxies are distinct from intergalactic gas clouds caused by galactic tidal interactions, since these gas clouds do not contain dark matter, so they do not technically qualify as galaxies. Distinguishing between intergalactic gas clouds and galaxies is difficult; most candidate dark galaxies turn out to be tidal gas clouds. The best candidate dark galaxies to date include HI1225+01, AGC229385, and numerous gas clouds detected in studies of quasars. On 25 August 2016, astronomers reported that Dragonfly 44, an ultra diffuse galaxy (UDG) with the mass of the Milky Way galaxy, but with nearly no discernable stars or galactic structure, is made almost entirely of dark matter. Ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magellanic Clouds
The Magellanic Clouds (''Magellanic system'' or ''Nubeculae Magellani'') are two irregular dwarf galaxies in the southern celestial hemisphere. Orbiting the Milky Way galaxy, these satellite galaxies are members of the Local Group. Because both show signs of a bar structure, they are often reclassified as Magellanic spiral galaxies. The two galaxies are: * Large Magellanic Cloud (LMC), approximately 163,000 light-years away * Small Magellanic Cloud (SMC), approximately 206,000 light years away Magellanic clouds are visible to the unaided eye in the Southern Hemisphere but they cannot be observed from the most northern latitudes. History The Magellanic Clouds have been known since ancient times to indigenous peoples across South America and Africa, and from the first millennium in Western Asia. The first preserved mention of the Large Magellanic Cloud is believed to be in petroglyphs and rock drawings found in Chile. They may be the objects mentioned by the polymath Ibn Qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way Subgroup
The Milky Way has several smaller galaxies gravitationally bound to it, as part of the Milky Way subgroup, which is part of the local galaxy cluster, the Local Group. There are 59 small galaxies confirmed to be within of the Milky Way, but not all of them are necessarily in orbit, and some may themselves be in orbit of other satellite galaxies. The only ones visible to the naked eye are the Large and Small Magellanic Clouds, which have been observed since prehistory. Measurements with the Hubble Space Telescope in 2006 suggest the Magellanic Clouds may be moving too fast to be orbiting the Milky Way. Of the galaxies confirmed to be in orbit, the largest is the Sagittarius Dwarf Elliptical Galaxy, which has a diameter of or roughly a twentieth that of the Milky Way. Characteristics Satellite galaxies that orbit from of the edge of the disc of the Milky Way Galaxy to the edge of the dark matter halo of the Milky Way at from the center of the galaxy, are generally depleted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VVV J161542
VVV may refer to: * ''VVV'' (magazine), a surrealist publication * VVV-Venlo, a Dutch football team * Valvoline, an American company which trades on the NYSE as VVV * Varsity Victory Volunteers, a Japanese-American paramilitary unit in Hawaii * ''Venus Versus Virus'' (a.k.a. V.V.V.), a manga by Atsushi Suzumi * Vereniging voor Vreemdelingenverkeer, the tourist board of the Netherlands * Vereeniging voor Vrouwenkiesrecht, the Dutch Association for Women's Suffrage * Vista Variables in the Via Lactea, an astronomical survey of the bulge and disk of our galaxy * ''Valvrave the Liberator'', a Japanese mecha anime series * Valhalla Vintage Verb, a computer program that creates reverberation effects for music production beside.... See also * VV (other) VV, V V, or v. v. may refer to: Arts and entertainment * Vopli Vidopliassova, or VV, a Ukrainian rock band * Vicarious Visions, a video game company * V/V, a secondary chord in music * V.V., a character in ''Code Geass'' P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cepheid Variable
A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid variable's luminosity and pulsation period established Cepheids as important indicators of cosmic benchmarks for scaling galactic and extragalactic distances. This robust characteristic of classical Cepheids was discovered in 1908 by Henrietta Swan Leavitt after studying thousands of variable stars in the Magellanic Clouds. This discovery allows one to know the true luminosity of a Cepheid by simply observing its pulsation period. This in turn allows one to determine the distance to the star, by comparing its known luminosity to its observed brightness. The term ''Cepheid'' originates from Delta Cephei in the constellation Cepheus, identified by John Goodricke in 1784, the first of its type to be so identified. The mechanics of stella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VVV J162559
VVV may refer to: * ''VVV'' (magazine), a surrealist publication * VVV-Venlo, a Dutch football team * Valvoline, an American company which trades on the NYSE as VVV * Varsity Victory Volunteers, a Japanese-American paramilitary unit in Hawaii * ''Venus Versus Virus'' (a.k.a. V.V.V.), a manga by Atsushi Suzumi * Vereniging voor Vreemdelingenverkeer, the tourist board of the Netherlands * Vereeniging voor Vrouwenkiesrecht, the Dutch Association for Women's Suffrage * Vista Variables in the Via Lactea, an astronomical survey of the bulge and disk of our galaxy * ''Valvrave the Liberator'', a Japanese mecha anime series * Valhalla Vintage Verb, a computer program that creates reverberation effects for music production beside.... See also * VV (other) VV, V V, or v. v. may refer to: Arts and entertainment * Vopli Vidopliassova, or VV, a Ukrainian rock band * Vicarious Visions, a video game company * V/V, a secondary chord in music * V.V., a character in ''Code Geass'' P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popular Science
''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, including the American Society of Magazine Editors awards for its journalistic excellence in 2003 (for General Excellence), 2004 (for Best Magazine Section), and 2019 (for Single-Topic Issue). With roots beginning in 1872, ''Popular Science'' has been translated into over 30 languages and is distributed to at least 45 countries. Early history '' The Popular Science Monthly'', as the publication was originally called, was founded in May 1872 by Edward L. Youmans to disseminate scientific knowledge to the educated layman. Youmans had previously worked as an editor for the weekly ''Appleton's Journal'' and persuaded them to publish his new journal. Early issues were mostly reprints of English periodicals. The journal became an outlet for writin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planet X
Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and continued at the start of the 20th with Percival Lowell's quest for Planet X. Lowell proposed the Planet X hypothesis to explain apparent discrepancies in the orbits of the giant planets, particularly Uranus and Neptune, speculating that the gravity of a large unseen ninth planet could have perturbed Uranus enough to account for the irregularities. Clyde Tombaugh's discovery of Pluto in 1930 appeared to validate Lowell's hypothesis, and Pluto was officially named the ninth planet. In 1978, Pluto was conclusively determined to be too small for its gravity to affect the giant planets, resulting in a brief search for a tenth planet. The search was largely abandoned in the early 1990s, when a study of measurements made by the ''Voyager 2'' spacecraft found that the irregularities observed in U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small Magellanic Cloud
The Small Magellanic Cloud (SMC), or Nubecula Minor, is a dwarf galaxy near the Milky Way. Classified as a dwarf irregular galaxy, the SMC has a D25 isophotal diameter of about , and contains several hundred million stars. It has a total mass of approximately 7 billion solar masses. At a distance of about 200,000 light-years, the SMC is among the nearest intergalactic neighbors of the Milky Way and is one of the most distant objects visible to the naked eye. The SMC is visible from the entire Southern Hemisphere, but can be fully glimpsed low above the southern horizon from latitudes south of about 15° north. The galaxy is located across both the constellations of Tucana and part of Hydrus, appearing as a faint hazy patch resembling a detached piece of the Milky Way. The SMC has an average apparent diameter of about 4.2° (8 times the Moon's) and thus covers an area of about 14 square degrees (70 times the Moon's). Since its surface brightness is very low, this deep-sky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (16 kpc) and the possible dwarf irregular galaxy known as the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is approximately across. It is roughly a hundredth as massive as the Milky WayMagellanic Cloud . ''''. 2009. Encyclopædia Britannica Online. 30 Aug. 2009. and is the fourth-largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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