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NGC 7098
NGC 7098 is a doubled barred spiral galaxy located about 95 million light-years away from Earth in the constellation of Octans. NGC 7098 has an estimated diameter of 152,400 light-years. NGC 7098 was discovered by astronomer John Herschel on September 22, 1835. NGC 7098 has a very prominent bar that is shaped like a broad oval with very prominent, nearly straight ansae. Surrounding the bar, an inner ring made of four tightly wrapped spiral arms is found. Located outside of the inner ring, a well-defined outer ring surrounding the inner region appears to have formed due to the wrapping of two spiral arms. It appears that both rings are being affected by new star formation Star formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—Jeans instability, collapse and form stars. As a branch of astronomy, sta .... However, there is no star formation in the core of NGC 709 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxy, galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William Herschel, William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the Celestial sphere, celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Formation
Star formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—Jeans instability, collapse and form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function. Most stars do not form in isolation but as part of a group of stars referred as star clusters or stellar associations. First stars Star formation is divided into three groups called "Populations". Population III stars formed from primordial hydrogen after the Big Bang. These stars are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC Objects
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's '' General Catalogue of Nebulae and Clusters of Stars''. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New General Catalogue'' (RNGC) by Jack W. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octans
Octans is a faint constellation located in the deep southern celestial hemisphere, Southern Sky. Its name is Latin for the eighth part of a circle, but it is named after the octant (instrument), octant, a navigational instrument. Devised by kingdom of France, French astronomer Nicolas Louis de Lacaille in 1752, Octans remains one of the IAU designated constellations, 88 modern constellations. The southern celestial pole is located within the boundaries of Octans. History and mythology Octans was one of 14 constellations created by French astronomer Nicolas Louis de Lacaille during his expedition to the Cape of Good Hope, and was originally named ''l’Octans de Reflexion'' (“the reflecting octant”) in 1752, after he had observed and catalogued almost 10,000 southern stars during a two-year stay at the Cape of Good Hope. He devised fourteen new constellations in uncharted regions of the Southern Celestial Hemisphere not visible from Europe. All but one honoured instruments that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barred Spiral Galaxies
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies in the local universe, and generally affect both the motions of stars and interstellar gas within spiral galaxies and can affect spiral arms as well. The Milky Way Galaxy, where the Solar System is located, is classified as a barred spiral galaxy. Edwin Hubble classified spiral galaxies of this type as "SB" (spiral, barred) in his Hubble sequence and arranged them into sub-categories based on how open the arms of the spiral are. SBa types feature tightly bound arms, while SBc types are at the other extreme and have loosely bound arms. SBb-type galaxies lie in between the two. SB0 is a barred lenticular galaxy. A new type, SBm, was subsequently created to describe somewhat irregular barred spirals, such as the Magellanic Clouds, which were once classified as irregular galaxies, but have since been found to contain barred spiral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Galaxies
A ring galaxy is a galaxy with a circle-like appearance. Hoag's Object, discovered by Arthur Hoag in 1950, is an example of a ring galaxy. The ring contains many massive, relatively young blue stars, which are extremely bright. The central region contains relatively little luminous matter. Some astronomers believe that ring galaxies are formed when a smaller galaxy passes through the center of a larger galaxy. Because most of a galaxy consists of empty space, this "collision" rarely results in any actual collisions between stars. However, the gravity, gravitational disruptions caused by such an event could cause a wave of star formation to move through the larger galaxy. Other astronomers think that rings are formed around some galaxies when external Accretion (astrophysics), accretion takes place. Star formation would then take place in the accreted material because of the shocks and compressions of the accreted material. Formation theories All of the processes that form ring g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 7020
NGC 7020 is a barred lenticular galaxy located about 140 million light-years away in the constellation Pavo. NGC 7020 was discovered by astronomer John Herschel on August 31, 1836. Physical characteristics NGC 7020 has a large outer ring surrounding a bright inner hexagonal zone containing an inner ring and possibly a bar. The large outer ring is completely detached from the inner hexagonal zone of the galaxy and is dominated by numerous flocculent spiral features. The outer ring has an estimated diameter of . The ring is knotty and bluer than the rest of the galaxy and shows where recent star formation is occurring in NGC 7020. The possible inner ring shows protruding features at the ends of its major axis therefore classifying it as a bar. The galaxy appears to be fairly free of ionized gas, which is not surprising for an early-type galaxy. Nearby galaxies NGC 7020 is member of a sparse group of galaxies that contains IC 5084, IC 5092, IC 5096, NGC 6943, NGC 7083, NGC 70 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 7013
NGC 7013 is a relatively nearby spiral or lenticular galaxy estimated to be around 37 to 41.4 million light-years away from Earth in the constellation of Cygnus. NGC 7013 was discovered by English astronomer William Herschel on July 17, 1784 and was also observed by his son, astronomer John Herschel on September 15, 1828. Physical characteristics NGC 7013 is tilted 90° to the Earth's line of sight, allowing its structure to be seen. However, NGC 7013 is classified as either as a spiral galaxy with tightly wound arms or as a lenticular galaxy. NGC 7013 is also considered part of a class of galactic nuclei that is defined by their spectral line emissions, called low-ionization nuclear emission-line region galaxies or LINERs. The galaxy appears to have two rings in its structure. The inner ring appears to completely disconnect from the central bulge while the stars in the outer ring appear to have very little spiral pattern. Optical images of NGC 7013 show that it has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dust Lane
A dust lane consists of relatively dense, obscuring clouds of interstellar dust, observed as a dark swath against the background of brighter object(s), especially a galaxy. These dust lanes can usually be seen in spiral galaxies, such as the Milky Way, when viewed from the edge. Due to the dense and relatively thick nature of this dust, observed light from a galaxy can be reduced by dust lanes by up to several magnitudes. In the Milky Way, this attenuation of visible light makes it impossible to see the stars behind the Great Rift through the bulge around the Galactic Center from Earth. This dust, as well as the gasses also found within these lanes, mixes and combines to form stars and planets. The gas in the dust lanes is funneled toward the Central Molecular Zone. Approximately one third of the gas will combine with the CMZ. The rest will overshoot and accrete at a later time. The presence of a dust lane is most apparent in disc galaxies that are viewed edge on. Altho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ansa
Ansa (Latin for "handle") or ANSA may refer to: Organizations * Agenzia Nazionale Stampa Associata, Italian news agency ** Ansa Mediterranean or ANSAmed, section of the above * Applied Neuroscience Society of Australasia * Association of Norwegian Students Abroad Science and technology Anatomy * Ansa cervicalis, a loop of nerves that are part of the cervical plexus * Ansa lenticularis, a part of the brain, making up the superior layer of the substantia innominata of Meynert * Loop of Henle (''ansa nephroni''), a portion of a nephron in the kidney * Ansa of the tympanal organ Astronomy * ''Ansae'', compact nebulosities such as can be found in protoplanetary nebulae * One of the apparent ends of the rings of Saturn Computing * Advanced Networked Systems Architecture, a 1990s, pre-CORBA, distributed systems architecture * ANSA Pre-processor, commercial pre-processing software (Automatic Net-generation for Structural Analysis) Other uses in science and technology * ''Ansa'' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Large Telescope
The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with a primary mirror that measures in diameter. These optical telescopes, named ''Antu'', ''Kueyen'', ''Melipal'', and ''Yepun'' (all words for astronomical objects in the Mapuche language), are generally used separately but can be combined to achieve a very high angular resolution. The VLT array is also complemented by four movable Auxiliary Telescopes (ATs) with apertures. The VLT is capable of observing both visible and infrared wavelengths. Each individual telescope can detect objects that are roughly four billion times fainter than what can be seen with the naked eye. When all the telescopes are combined, the facility can achieve an angular resolution of approximately 0.002 arcsecond. In single telescope mode, the angular resol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor and experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an Inductive reasoning, inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer Sir William Herschel. He was the nephew of astronomer Caroline Herschel. He studied short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
