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Snake Nebula
The Snake Nebula (also known as Barnard 72) is a dark nebula in the Ophiuchus, Ophiuchus constellation. It is a small but readily apparent SP-shaped dust lane that snakes out in front of the Milky Way star clouds from the north-north-west edge of the bowl of the Pipe Nebula. Its thickness runs between 2′ and 3′ and runs around 6′ in the north-west / south-east orientation. A good view in a 4" to 6" telescope requires clear dark skies. It is part of the much larger Dark Horse (astronomy), Dark Horse Nebula. To the right of the Snake Nebula is Barnard 68. Below it is Barnard 69, Barnard 70, and Barnard 74. External links * * {{Cite APOD , date=20 February 2009, title=Snake in the Dark Dark nebulae Barnard objects Ophiuchus (constellation) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minute Of Arc
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol , is of an arcminute, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in ast ... [...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] |
Nebula
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dust Lane
A dust lane consists of a relatively dense, obscuring clouds of interstellar dust, observed as a dark swath against the background of a 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, light from the galaxy is reduced by 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, mix and combine to form stars and planets. See also * Interplanetary medium ** Interplanetary dust ** Interstellar dust ** Intergalactic dust * Extinction (astronomy) * Star formation Star formation is the process by which dense regions within molecular clouds in [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipe Nebula
The Pipe Nebula (also known as Barnard 59, 65–67, and 78) is a dark nebula in the Ophiuchus constellation and a part of the Dark Horse Nebula. It is a large but readily apparent smoking pipe-shaped dust lane that obscures the Milky Way star clouds behind it. Clearly visible to the naked eye in the Southern United States under clear dark skies, but it is best viewed with 7× binoculars. The nebula has two main parts: the Pipe Stem with an opacity of 6 which is composed of Barnard 59, 65, 66, and 67 (also known as LDN 1773) 300′ x 60′ RA: 17h 21m Dec: −27° 23′; and the Bowl of the Pipe with an opacity of 5 which is composed of Barnard 78 (also known as LDN 42) 200′ x 140′ RA: 17h 33m Dec: −26° 30′. Gallery File:Guisard - Milky Way.jpg, The Milky Way between Sagittarius and Scorpius: the Pipe Nebula is visible slightly above and left of center. File:Laser Towards Milky Ways Centre.jpg, View of the Milky Way and the Great Rift from ESO's Very Large Tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Horse (astronomy)
The Dark Horse Nebula or Great Dark Horse (sometimes called the Prancing Horse) is a large dark nebula that, from Earth's perspective, obscures part of the upper central bulge of the Milky Way. The Dark Horse lies in the equatorial constellation Ophiuchus (the Serpent Bearer), near its borders with the more famous constellations Scorpius and Sagittarius. It is a large, visible feature of the Milky Way's Great Rift, uniting several individually catalogued dark nebulae, including the Pipe Nebula. It is visible from Earth only on clear moonless nights without light pollution and with low humidity. Name This region of dark nebulae is called Dark Horse because it resembles the side silhouette of a horse and appears dark as compared with the background glow of stars and star clouds. It is also known as "Great" because it is one of the largest (in apparent size) groups of dark nebulae in the sky. Nearby nebulae The rear of the Great Dark Horse (its rump and hind legs), is also know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard 68
Barnard 68 is a molecular cloud, dark absorption nebula or Bok globule, towards the southern constellation Ophiuchus and well within the Milky Way galaxy at a distance of about 500 light-years, so close that not a single star can be seen between it and the Sun. American astronomer Edward Emerson Barnard added this nebula to his catalog of dark nebulae in 1919. His catalog was published in 1927, at which stage it included some 350 objects. Because of its opacity, its interior is extremely cold, its temperature being about 16 K (−257 °C/-431 °F). Its mass is about twice that of the Sun and it measures about half a light-year across. Characteristics Despite being opaque at visible-light wavelengths, use of the Very Large Telescope at Cerro Paranal has revealed the presence of about 3,700 blocked background Milky Way stars, some 1,000 of which are visible at infrared wavelengths. Careful measurements of the degree of obscuration resulted in a finely sampled and acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard 69
Barnard is a version of the surname Bernard, which is a French and West Germanic masculine given name and surname. The surname means as tough as a bear, Bar(Bear)+nard/hard(hardy/tough) __NOTOC__ People Some of the people bearing the surname Barnard in England are thought to have arrived after the time of the Norman Conquest (1066), Changing their surnames from Bernard to Barnard. Some of whom, it has been suggested, can be traced back to Hugo Bernard. Some of the Barnard family in England may have been Huguenots who fled from the Atlantic coast region of France ''circa'' 1685 (the time of the revocation of the edict of Nantes) or earlier than that date. By contrast, the Barnard family in Holland (the western provinces of the Netherlands) can be definitively traced back to ''circa'' 1751 (Izaak Barnard) of Scheveningen.The surname Barnard is also found in South Africa among the Afrikaner community. An example of this is Christiaan Barnard, A South African Cardiac Surgeon w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard 70
Barnard is a version of the surname Bernard, which is a French and West Germanic masculine given name and surname. The surname means as tough as a bear, Bar(Bear)+nard/hard(hardy/tough) __NOTOC__ People Some of the people bearing the surname Barnard in England are thought to have arrived after the time of the Norman Conquest (1066), Changing their surnames from Bernard to Barnard. Some of whom, it has been suggested, can be traced back to Hugo Bernard. Some of the Barnard family in England may have been Huguenots who fled from the Atlantic coast region of France ''circa'' 1685 (the time of the revocation of the edict of Nantes) or earlier than that date. By contrast, the Barnard family in Holland (the western provinces of the Netherlands) can be definitively traced back to ''circa'' 1751 (Izaak Barnard) of Scheveningen.The surname Barnard is also found in South Africa among the Afrikaner community. An example of this is Christiaan Barnard, A South African Cardiac Surgeon w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard 74
Barnard is a version of the surname Bernard, which is a French and West Germanic masculine given name and surname. The surname means as tough as a bear, Bar(Bear)+nard/hard(hardy/tough) __NOTOC__ People Some of the people bearing the surname Barnard in England are thought to have arrived after the time of the Norman Conquest (1066), Changing their surnames from Bernard to Barnard. Some of whom, it has been suggested, can be traced back to Hugo Bernard. Some of the Barnard family in England may have been Huguenots who fled from the Atlantic coast region of France ''circa'' 1685 (the time of the revocation of the edict of Nantes) or earlier than that date. By contrast, the Barnard family in Holland (the western provinces of the Netherlands) can be definitively traced back to ''circa'' 1751 (Izaak Barnard) of Scheveningen.The surname Barnard is also found in South Africa among the Afrikaner community. An example of this is Christiaan Barnard, A South African Cardiac Surgeon w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Nebulae
A dark nebula or absorption nebula is a type of interstellar cloud, particularly molecular clouds, that is so dense that it obscures the visible wavelengths of light from objects behind it, such as background stars and emission or reflection nebulae. The extinction of the light is caused by interstellar dust grains located in the coldest, densest parts of molecular clouds. Clusters and large complexes of dark nebulae are associated with Giant Molecular Clouds. Isolated small dark nebulae are called Bok globules. Like other interstellar dust or material, things it obscures are only visible using radio waves in radio astronomy or infrared in infrared astronomy. Dark clouds appear so because of sub-micrometre-sized dust particles, coated with frozen carbon monoxide and nitrogen, which effectively block the passage of light at visible wavelengths. Also present are molecular hydrogen, atomic helium, C18O (CO with oxygen as the 18O isotope), CS, NH3 (ammonia), H2CO (formaldehyde), c-C3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard Objects
Barnard is a version of the surname Bernard, which is a French and West Germanic masculine given name and surname. The surname means as tough as a bear, Bar(Bear)+nard/hard(hardy/tough) __NOTOC__ People Some of the people bearing the surname Barnard in England are thought to have arrived after the time of the Norman Conquest (1066), Changing their surnames from Bernard to Barnard. Some of whom, it has been suggested, can be traced back to Hugo Bernard. Some of the Barnard family in England may have been Huguenots who fled from the Atlantic coast region of France ''circa'' 1685 (the time of the revocation of the edict of Nantes) or earlier than that date. By contrast, the Barnard family in Holland (the western provinces of the Netherlands) can be definitively traced back to ''circa'' 1751 (Izaak Barnard) of Scheveningen.The surname Barnard is also found in South Africa among the Afrikaner community. An example of this is Christiaan Barnard, A South African Cardiac Surgeon who pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
