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Great Rift (astronomy)
In astronomy, the Great Rift (sometimes called the Dark Rift or less commonly the Dark River) is a dust lane, dark band caused by interstellar clouds of cosmic dust that significantly obscure (extinction (astronomy), extinguish) the Galactic Center, center and most radial sectors of the Milky Way galaxy from Earth's perspective. In dark, clear night sky, night skies, the rift appears as clear as the bright galactic bulge, bulge of stars around the Galactic Center does to the naked eye or binoculars. The rift is largely between the Solar System (which is close to the inner edge of the Orion Arm) and the next arm, inward, the Sagittarius Arm. The clouds are an obstruction to millions of the galaxy's stars detected at visible spectrum, visible wavelengths, which compose a bright hazy band appearing angular diameter, 30° wide and arching through the night sky. The clouds within our radial sector of the galaxy span about from Earth. The clouds are estimated to contain about 1 millio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rho Ophiuchi Cloud Complex
The Rho Ophiuchi cloud complex is a complex of interstellar clouds with different nebulae, particularly dark nebulae which is centered 1° south of the star ρ Ophiuchi, which it among others extends to, of the constellation Ophiuchus. At an estimated distance of , or 460 light years, it is one of the closest star-forming regions to the Solar System. Cloud complex This cloud covers an angular area of on the celestial sphere. It consists of two major regions of dense gas and dust. The first contains a star-forming cloud (L1688) and two filaments (L1709 and L1755), while the second has a star-forming region (L1689) and a filament (L1712–L1729). These filaments extend up to 10–17.5 parsecs in length and can be as narrow as 0.24 parsecs in width. The large extensions of the complex are also called ''Dark River'' clouds (or ''Rho Ophiuchi Streamers'') and are identified as Barnard 44 and 45. Some of the structures within the complex appear to be the result of a shock front pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittarius Arm
Sagittarius ( ) may refer to: *Sagittarius (constellation) *Sagittarius (astrology), a sign of the Zodiac Ships *'' SuperStar Sagittarius'', a cruise ship * USS ''Sagittarius'' (AKN-2), a World War II US Navy cargo ship Music *Sagittarius (band), an American sunshine pop studio group * Ensemble Sagittarius, an ensemble conducted by Michel Laplénie Fictional characters *Sagittarius (comics), member of Zodiac, an evil group in the Marvel Universe *Sagittarius Aiolos, a character in ''Saint Seiya'' *Sagittarius, a ''Fairy Tail'' character Zoology *''Sagittarius serpentarius'' or secretarybird, a large, mostly terrestrial bird of prey *''Sibynophis sagittarius'', a species of snake found in South Asia Other uses *Sagittarii, Ancient Roman archers *Sagittario or Sagittarius, a Beyblade toy See also *Sagittarius Dwarf Galaxy (other) * * *Sagitta (other) *''Sagittaria ''Sagittaria'' is a genus of about 30 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiuchus
Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. An old alternative name for the constellation was Serpentarius (). Location Ophiuchus lies between Aquila, Serpens, Scorpius, Sagittarius, and Hercules, northwest of the center of the Milky Way. The southern part lies between Scorpius to the west and Sagittarius to the east. In the northern hemisphere, it is best visible in summer. It is opposite of Orion. Ophiuchus is depicted as a man grasping a serpent; the interposition of his body divides the snake constellation Serpens into two parts, Serpens Caput and Serpens Cauda. Ophiuchus straddles the equator with the majority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cygnus Rift
In astronomy, the Great Rift (sometimes called the Dark Rift or less commonly the Dark River) is a dark band caused by interstellar clouds of cosmic dust that significantly obscure ( extinguish) the center and most radial sectors of the Milky Way galaxy from Earth's perspective. In dark, clear night skies, the rift appears as clear as the bright bulge of stars around the Galactic Center does to the naked eye or binoculars. The rift is largely between the Solar System (which is close to the inner edge of the Orion Arm) and the next arm, inward, the Sagittarius Arm. The clouds are an obstruction to millions of the galaxy's stars detected at visible wavelengths, which compose a bright hazy band appearing 30° wide and arching through the night sky. The clouds within our radial sector of the galaxy span about from Earth. The clouds are estimated to contain about 1 million solar masses of plasma and dust. Properties To the naked eye, the Great Rift appears as a dark lane that di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cygnus (constellation)
Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. Cygnus is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. Cygnus contains Deneb (ذنب, translit. ''ḏanab,'' tail)one of the brightest stars in the night sky and the most distant first-magnitude staras its "tail star" and one corner of the Summer Triangle. It also has some notable X-ray sources and the giant stellar association of Cygnus OB2. Cygnus is also known as the Northern Cross. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Coalsack
Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. Cygnus is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. Cygnus contains Deneb (ذنب, translit. ''ḏanab,'' tail)one of the brightest stars in the night sky and the most distant first-magnitude staras its "tail star" and one corner of the Summer Triangle. It also has some notable X-ray sources and the giant stellar association of Cygnus OB2. Cygnus is also known as the Northern Cross. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America Nebula
The North America Nebula (NGC 7000 or Caldwell 20) is an emission nebula in the constellation Cygnus, close to Deneb (the tail of the swan and its brightest star). The shape of the nebula resembles that of the continent of North America, complete with a prominent Gulf of Mexico. History On October 24, 1786, William Herschel observing from Slough, England, noted a “faint milky nebulosity scattered over this space, in some places pretty bright.” The most prominent region was catalogued by his son John Herschel on August 21, 1829. It was listed in the New General Catalogue as NGC 7000, where it is described as a "faint, most extremely large, diffuse nebulosity.” In 1890, the pioneering German astrophotographer Max Wolf noticed this nebula's characteristic shape on a long-exposure photograph, and dubbed it the North America Nebula. In his study of nebulae on the Palomar Sky Survey plates in 1959, American astronomer Stewart Sharpless realised that the North America Nebula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naked Eye
Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying, light-collecting optical instrument, such as a telescope or microscope, or eye protection. Vision corrected to normal acuity using corrective lenses is still considered "naked". In astronomy, the naked eye may be used to observe celestial events and objects visible without equipment, such as conjunctions, passing comets, meteor showers, and the brightest asteroids, including 4 Vesta. Sky lore and various tests demonstrate an impressive variety of phenomena visible to the unaided eye. Basic properties Some basic properties of the human eye are: *Quick autofocus from distances of 25 cm (young people) to 50 cm (most people 50 years and older) to infinity. * Angular resolution: about 1 arcminute, approximately 0.017° or 0.0003 radians, which corresponds to 0.3 m at a 1 km distance. *Field of view (FOV): simultaneous visual percepti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Towards Milky Ways Centre
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light which is coherence (physics), ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and Photolithography#Light sources, lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimated light, collimation), enabling applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which allows them to emit light with a very narrow frequency spectrum, spectru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth & Sky
''Earth & Sky'' was a daily radio series that presented information about science and nature. It began broadcasting in 1991 and ceased operations in 2013. ''EarthSky'' is the ongoing website, serving 21 million users in 2019, according to Google Analytics. ''Earth & Sky'' was the creation of producers Deborah Byrd and Joel Block, who were also the hosts. Byrd had previously created the radio program '' Star Date'' that began broadcasting in the US in 1978, and Block was ''Star Dates original host. ''Earth & Sky'' presented 60- and 90-second radio spots (called "modules") on a wide variety of scientific topics, communicating through terrestrial radio as well as satellite radio and internet radio. ''Earth & Sky'' was aired one or more times daily on more than 1,000 commercial, NPR, and other public radio stations, 80 affiliate stations for the sight-impaired, and across 35 channels on both XM and Sirius satellite radio in the United States. Abroad, the programming iwas heard o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () 1, where \nu_ is the electron gyrofrequency and \nu_ is the electron collision rate. It is often the case that the electrons are magnetized while the ions are not. Magnetized plasmas are ''anisotropic'', meaning that their properties in the direction parallel to the magnetic field are different from those perpendicular to it. While electric fields in plasmas are usually small due to the plasma high conductivity, the electric field associated with a plasma moving with velocity \mathbf in the magnetic field \mathbf is given by the usual Lorentz force, Lorentz formula \mathbf = -\mathbf\times\mathbf, and is not affected by Debye shielding. Mathematical descriptions To completely describe the state of a plasma, all of the particle locations and velocities that describe the electromagnetic field in the plasma region would need to be written down. However, it is generally not practical or necessary to keep track of all the particles in a plasma. Therefore, plasma physicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
