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Sharpless Catalog
The Sharpless catalog is a list of 313 H II regions (emission nebulae) intended to be comprehensive north of declination −27°. (It does include some nebulae south of that declination as well.) The first edition was published in 1953 with 142 objects (Sh1), and the second and final version was published by US astronomer Stewart Sharpless in 1959 with 312 objects. Sharpless also includes some planetary nebulae and supernova remnants, in addition to H II regions. In 1953 Stewart Sharpless joined the staff of the United States Naval Observatory Flagstaff Station, where he surveyed and cataloged H II regions of the Milky Way using the images from the Palomar Sky Survey. From this work Sharpless published his catalog of H II regions in two editions: the first in 1953, with 142 nebula; and the second and final edition in 1959, with 312 nebulae.Stewart SharplessA Catalogue of H II Regions ''Astrophysical Journal'' Supplement, vol. 4, p.257, 1959 Sharpless coordinates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H II Region
An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light years, and density from a few to about a million particles per cubic centimetre. The Orion Nebula, now known to be an H II region, was observed in 1610 by Nicolas-Claude Fabri de Peiresc by telescope, the first such object discovered. The regions may be of any shape because the distribution of the stars and gas inside them is irregular. The short-lived blue stars created in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. They often appear clumpy and filamentary, sometimes showing intricate shapes such as the Horsehead Nebula. H II regions may give birth to tho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 6302HST
NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * National Gas Company of Trinidad and Tobago, state-owned natural gas company in Trinidad and Tobago * National Grid plc, a former name of National Grid Electricity Transmission plc, the operator of the British electricity transmission system * Northrop Grumman Corporation, aerospace and defense conglomerate formed from the merger of Northrop Corporation and Grumman Corporation in 1994 * Numismatic Guaranty Corporation, coin certification company in the United States Other uses * National Gallery of Canada, art gallery founded in 1880 in Ottawa, Canada * National Geographic, documentary and reality television channel established in the United States in 2001 formerly called National Geographic Channel * Native Girls Code, US non-profit organisat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westerhout 40
Westerhout 40 or W40 (also designated Sharpless 64, Sh2-64, or RCW 174) is a star-forming region in the Milky Way located in the constellation Serpens. In this region, interstellar gas forming a diffuse nebula surrounds a cluster of several hundred new-born stars. The distance to W40 is 436 ± 9 pc (1420 ± 30 light years), making it one of the closest sites of formation of high-mass O-type and B-type stars. The ionizing radiation from the massive OB stars has created an H II region, which has an hour-glass morphology. Dust from the molecular cloud in which W40 formed obscures the nebula, rendering W40 difficult to observe at visible wavelengths of light. Thus, X-ray, infrared, and radio observations have been used to see through the molecular cloud to study the star-formation processes going on within. W40 appears near to several other star-forming regions in the sky, including an infrared dark cloud designated Serpens South and a young stellar cluster designated the Ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eagle Nebula From ESO
Eagle is the common name for many large Bird of prey, birds of prey of the family Accipitridae. Eagles belong to several groups of Genus, genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, just 14 species can be found—2 in North America, 9 in Central and South America, and 3 in Australia. Eagles are not a natural group but denote essentially any kind of bird of prey large enough to hunt sizeable (about 50 cm long or more overall) vertebrate, vertebrates. Description Eagles are large, powerfully-built birds of prey, with heavy heads and beaks. Even the smallest eagles, such as the booted eagle (''Aquila pennata''), which is comparable in size to a common buzzard (''Buteo buteo'') or red-tailed hawk (''B. jamaicensis''), have relatively longer and more evenly broad wings, and more direct, faster flight – despite the reduced size of aerodynamic feathers. Most eagles are larger than any other raptors apart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eagle Nebula
The Eagle Nebula (catalogued as Messier 16 or M16, and as NGC 6611, and also known as the Star Queen Nebula) is a young open cluster of stars in the constellation Serpens, discovered by Jean-Philippe de Cheseaux in 1745–46. Both the "Eagle" and the "Star Queen" refer to visual impressions of the dark silhouette near the center of the nebula, an area made famous as the "Pillars of Creation" imaged by the Hubble Space Telescope. The nebula contains several active star-forming gas and dust regions, including the aforementioned Pillars of Creation. The Eagle Nebula lies in the Sagittarius Arm of the Milky Way. Characteristics The Eagle Nebula is part of a diffuse emission nebula, or H II region, which is catalogued as IC 4703. This region of active current star formation is about 5700 light-years distant. A spire of gas that can be seen coming off the nebula in the northeastern part is approximately 9.5 light-years or about 90 trillion kilometers long. The cluster associated wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omega Nebula
The Omega Nebula, also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula (catalogued as Messier 17 or M17 or NGC 6618) is an H II region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is by some of the richest starfields of the Milky Way, figuring in the northern two-thirds of Sagittarius. Characteristics The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud of interstellar matter of which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses. The total mass of the Omega Nebula is an estimated 800 solar masses. It is considered one of the brightest and most massive star-forming regions of our galaxy. Its local geometry is similar to the Orion Nebula except that it is viewed edge-on rather than face-on.. The open cluster NGC 6618 lies embedded i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifid ''
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Trifid is Latin for "split into three parts" or "threefold" and may refer to: * ''Trifid'' (journal), a Czech-language periodical *Trifid Nebula in the constellation Sagittarius *Trifid cipher, a fractionated cipher * Trifid (software), suite of manufacturing software by Plessey. Distinguish from *Triffid, a fictional dangerous mobile plant in the 1951 novel ''The Day of the Triffids'' by John Wyndham *The Triffids, a popular Australian band named for the plant See also * ''The Day of the Triffids (other) ''The Day of the Triffids ''The Day of the Triffids'' is a 1951 post-apocalyptic novel by the English science fiction author John Wyndham. After most people in the world are blinded by an apparent meteor shower, an aggressive species of plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifid Nebula
The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an H II region in the north-west of Sagittarius in a star-forming region in the Milky Way's Scutum-Centaurus Arm. It was discovered by Charles Messier on June 5, 1764. Its name means 'three-lobe'. The object is an unusual combination of an open cluster of stars, an emission nebula (the relatively dense, reddish-pink portion), a reflection nebula (the mainly NNE blue portion), and a dark nebula (the apparent 'gaps' in the former that cause the trifurcated appearance, also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers. The most massive star that has formed in this region is HD 164492A, an O7.5III star with a mass more than 20 times the mass of the Sun. This star is surrounded by a cluster of approximately 3100 young stars. Characteristics The Trifid Nebula was the subject of an investig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebulae Sharpless-29
A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the "Pillars of Creation" in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter, and eventually will become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects. Most nebulae are of vast size; some are hundreds of light-years in diameter. A nebula that is visible to the human eye from Earth would appear larger, but no brighter, from close by. The Orion Nebula, the brightest nebula in the sky and occupying an area twice the angular diameter of the full Moon, can be viewed with the naked eye but was missed by early astronomers. Although denser than the space sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagoon Nebula
The Lagoon Nebula (catalogued as Messier 8 or M8, NGC 6523, Sharpless 25, RCW 146, and Gum 72) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region. The Lagoon Nebula was discovered by Giovanni Hodierna before 1654 and is one of only two star-forming nebulae faintly visible to the eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct cloud-like patch with a definite core. Within the nebula is the open cluster NGC 6530. Characteristics The Lagoon Nebula is estimated to be between 4,000–6,000 light-years away from the Earth. In the sky of Earth, it spans 90' by 40', which translates to an actual dimension of 110 by 50 light years. Like many nebulae, it appears pink in time-exposure color photos but is gray to the eye peering through binoculars or a telescope, human vision having poor color sensitivity at low light levels. The nebula contains a number of Bok globules (dark, collapsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
