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Horsehead Nebula
The Horsehead Nebula (also known as Barnard 33 or B33) is a small dark nebula in the constellation Orion. The nebula is located just to the south of Alnitak, the easternmost star of Orion's Belt, and is part of the much larger Orion molecular cloud complex. It appears within the southern region of the dense dust cloud known as Lynds 1630, along the edge of the much larger, active star-forming H II region called IC 434. The Horsehead Nebula is approximately 422 parsecs or 1,375 light-years from Earth. It is one of the most identifiable nebulae because of its resemblance to a horse's head. History The nebula was discovered by Scottish astronomer Williamina Fleming in 1888 on a photographic plate taken at the Harvard College Observatory. One of the first descriptions was made by E. E. Barnard, describing it as: "Dark mass, diam. 4′, on nebulous strip extending south from ζ Orionis", cataloguing the dark nebula as Barnard 33. Structure The dark cloud of dust and gas is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebulosa Testa Di Cavallo Con SPECULOOS
''Nebulosa'' is a genus of moths of the family Notodontidae Notodontidae is a family of moths with approximately 3,800 known species. The family was described by James Francis Stephens in 1829. Moths of this family are found in all parts of the world, but they are most concentrated in tropical areas, es .... It consists of the following species: *'' Nebulosa albitumida'' (Dognin, 1902) *'' Nebulosa aliena'' (Dognin, 1904) *'' Nebulosa bialbifera'' (Warren, 1904) *'' Nebulosa cistrina'' (Druce, 1899) *'' Nebulosa cistrinoides'' (Dognin, 1909) *'' Nebulosa cletor'' (Druce, 1893) *'' Nebulosa creon'' (Druce, 1885) *'' Nebulosa crypsispila'' (Warren, 1901) *'' Nebulosa delicata'' Miller, 2008 *'' Nebulosa elicioi'' Miller, 2008 *'' Nebulosa erymas'' (Druce, 1885) *'' Nebulosa fulvipalpis'' (Dognin, 1910) *'' Nebulosa grimaldii'' Miller, 2008 *'' Nebulosa halesius'' (Druce, 1885) *'' Nebulosa hermani'' Miller, 2008 *'' Nebulosa huacamayensis'' Miller, 2008 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnard Catalogue
The Barnard Catalogue is an astronomical catalogue of dark nebulae. A version of the Barnard Catalogue, containing 349 objects, can be accessed via VizieR. History In 1919, the American astronomer Edward Emerson Barnard compiled a list of dark nebulae known as the ''Barnard Catalogue of Dark Markings in the Sky'', or the ''Barnard Catalogue'' for short. The nebulae listed by Barnard have become known as Barnard objects. A 1919 version of the catalogue listed 182 nebulae; by the time of the posthumously published 1927 version, it listed 369. Barnard's niece and assistant Mary Ross Calvert, also an astronomer and astrographer, took an important part in creating the catalogue. See also * List of dark nebulae * Lynds' Catalogue of Dark Nebulae References * Further reading * Hunter, Tim B., Dobek, Gerald O. and McGaha, James E. (2023). The Barnard Objects: Then and Now. Springer. ISBN 9783031314841. External links Barnard's Catalogue of 349 Dark Objects in the Sk ... [...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 spectrum, visible wavelengths of light from objects behind it, such as background stars and emission nebula, emission or reflection nebula, reflection nebulae. The extinction (astronomy), extinction of the light is caused by cosmic dust, interstellar dust grains 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, the things it obscures are visible only 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horsehead Nebula
The Horsehead Nebula (also known as Barnard 33 or B33) is a small dark nebula in the constellation Orion. The nebula is located just to the south of Alnitak, the easternmost star of Orion's Belt, and is part of the much larger Orion molecular cloud complex. It appears within the southern region of the dense dust cloud known as Lynds 1630, along the edge of the much larger, active star-forming H II region called IC 434. The Horsehead Nebula is approximately 422 parsecs or 1,375 light-years from Earth. It is one of the most identifiable nebulae because of its resemblance to a horse's head. History The nebula was discovered by Scottish astronomer Williamina Fleming in 1888 on a photographic plate taken at the Harvard College Observatory. One of the first descriptions was made by E. E. Barnard, describing it as: "Dark mass, diam. 4′, on nebulous strip extending south from ζ Orionis", cataloguing the dark nebula as Barnard 33. Structure The dark cloud of dust and gas is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Hubble Anniversary Images
This is a list of images released to celebrate the Hubble Space Telescope's anniversaries. They celebrate its "birthday" when it was STS-31, launched into orbit on April 24, 1990, by the crew of Space Shuttle Discovery, Space Shuttle ''Discovery''. 15th (2005) The 15th anniversary, in 2005, was celebrated with a collection of images of Whirlpool Galaxy, M51 (the Whirlpool Galaxy), and also with a section of the Eagle Nebula. The 15th anniversary included a collection of other content including, in multiple languages, the video release, ''Hubble — 15 Years of Discovery''. 16th (2006) 17th (2007) The 17th-anniversary celebration featured a panorama of part of the Carina Nebula, and a collection of images selected from that area. 18th (2008) 59 images of merging galaxies were released for the 18th anniversary on 24 April 2008. 19th (2009) 20th (2010) 21st (2011) 22nd (2012) 23rd (2013) 24th (2014) 25th (2015) 26th (2016) 27th (2017) 28th (2018 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orion Belt
Orion's Belt is an asterism in the constellation of Orion. Other names include the Belt of Orion, the Three Kings, and the Three Sisters. The belt consists of three bright and easily identifiable collinear star systems – Alnitak, Alnilam, and Mintaka – nearly equally spaced in a line, spanning an angular size of ~ (2.3°). Owing to the high surface temperatures of their constituent stars, the intense light emitted is blue-white in color. In spite of their spot-like appearance, only Alnilam is a single star; Alnitak is a triple star system, and Mintaka a sextuple. All three owe their luminosity to the presence of one or more blue supergiants. The brightest as viewed from Sol is Alnilam, with an apparent magnitude of 1.69, followed by Alnitak at 1.74 and Mintaka at 2.25. The ten stars of the three systems have a combined luminosity approximately 970,000 times that of the Sun. Orion's Belt appears widely in historical literature and in various cultures, under many diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstellar Cloud
An interstellar cloud is an accumulation of gas, plasma, and cosmic dust in galaxies. Put differently, an interstellar cloud is a denser-than-average region of the interstellar medium, the matter and radiation that exists in the space between the star systems in a galaxy. Depending on the density, size, and temperature of a given cloud, its hydrogen can be neutral, making an H I region; ionized, or plasma making it an H II region; or molecular, which are referred to simply as molecular clouds, or sometime dense clouds. Neutral and ionized clouds are sometimes also called ''diffuse clouds''. An interstellar cloud is formed by the gas and dust particles from a red giant in its later life. Chemical compositions The chemical composition of interstellar clouds is determined by studying electromagnetic radiation that they emanate, and we receive – from radio waves through visible light, to gamma rays on the electromagnetic spectrum – that we receive from them. Large radio tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Dust
Cosmic dustalso called extraterrestrial dust, space dust, or star dustis dust that occurs in outer space or has fallen onto Earth. Most cosmic dust particles measure between a few molecules and , such as micrometeoroids (30 μm). Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (as in the zodiacal cloud), and circumplanetary dust (as in a planetary ring). There are several methods to obtain space dust measurement. In the Solar System, interplanetary dust causes the zodiacal light. Solar System dust includes comet dust, planetary dust (like from Mars), asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. Thousands of tons of cosmic dust are estimated to reach Earth's surface every year, with most grains having a mass between 10−16 kg (0.1 pg) and 10−4 kg (0.1 g). The density of the dust cloud through which the Earth is traveling is approximately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, electric currents, and electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function (mathematics), function assigning a Euclidean vector, vector to each point of space, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma Orionis
Sigma Orionis or Sigma Ori (σ Orionis, σ Ori) is a multiple star system in the constellation Orion (constellation), Orion, consisting of the brightest members of a young open cluster. It is found at the eastern end of Orion's Belt, the belt, south west of Alnitak and west of the Horsehead Nebula which it partially illuminates. The combined brightness of the component stars is magnitude 3.80. History σ Orionis is a naked eye star at the eastern end of Orion's Belt, and has been known since antiquity, but it was not included in Ptolemy's Almagest. It was referred to by Al Sufi, but not formally listed in his catalogue. In more modern times, it was measured by Tycho Brahe and included in his catalogue. In Kepler's extension it is described as "Quae ultimam baltei praecedit ad austr." (preceding the outermost of the belt, to the south). It was then recorded by Johann Bayer in his Uranometria as a single star with the Greek letter σ (sigma). He described i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H-alpha
Hydrogen-alpha, typically shortened to H-alpha or Hα, is a deep-red visible spectral line of the hydrogen atom with a wavelength of 656.28 nm in air and 656.46 nm in vacuum. It is the first spectral line in the Balmer series and is emitted when an electron falls from a hydrogen atom's third- to second-lowest energy level. H-alpha has applications in astronomy where its emission can be observed from emission nebulae and from features in the Sun's atmosphere, including solar prominences and the chromosphere. Balmer series According to the Bohr model of the atom, electrons exist in quantized energy levels surrounding the atom's nucleus. These energy levels are described by the principal quantum number ''n'' = 1, 2, 3, ... . Electrons may only exist in these states, and may only transit between these states. The set of transitions from ''n'' ≥ 3 to ''n'' = 2 is called the Balmer series and its members are named sequentially by Greek letters: *''n'' = 3 to ''n'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the chemical formula, formula , called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas (dihydrogen) and in molecular forms, such as in water and organic compounds. The most common isotope of hydrogen (H) consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
