An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 36 Search : hole
Lockman hole
  سوراخ ِ لاکمن   
surâx-e Lockman

Fr.: trou de Lockman   

A region in the sky lying roughly between the → pointer stars of the → Big Dipper that is almost free from → neutral hydrogen gas in the → Galaxy. It is centered at R.A. 10h 45m, Dec. +57° 20', has an area of 15 square degrees, and a → column density of NH I ≤ 5 x 1018 cm-2. The Lockman hole is one of the favorite directions for obtaining a clear and unobstructed view of objects in deep space, far beyond our own Galaxy.

Named after Felix J. Lockman et al., 1986, ApJ 302, 432; → hole.

massive black hole
  سیه‌چال ِ پرجرم   
siyahcâl-e porjerm

Fr.: trou noir massif   

A black hole with a mass between millions and billions of solar masses residing in galactic nuclei. The mass of this type of black holes represents about 0.2% of the bulge mass. When matter is swallowed by the black hole, this gives rise to the tremendous energetic phenomena observed in quasars and active galactic nuclei.

massive; → black hole.

mini black hole
mini siyahcâl

Fr.: mini corps noir   

A black hole of mass as low as 10-6 gram supposed to have formed in the early Universe following the Big Bang event. Same as primordial black hole.

Mini a shortening of → minimum; → black hole.

ozone hole
  سوراخِ اُزون   
surâx-e ozon (#)

Fr.: trou d'ozone   

Not really a "hole," but a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August-October). It was first noticed in the 1970s by a research group from the British Antarctic Survey.

ozone; → hole.

primordial black hole
  سیه‌چال ِ بن‌آغازین   
siyahcâl-e bonâqâzin

Fr.: trou noir primordial   

A black hole formed following the Big Bang event due to incredibly violent turbulence that squeezed concentrations of matter to high densities. These black holes, first suggested by Stephen Hawking, are expected to have a mass comparable to that of a mountain and a size as small as an atom. Same as → mini black hole.

primordial; → black hole.

Reissner-Nordstrom black hole
  سیه‌چال ِ رایسنر-نوردستروم   
siyah câl-e Reissner-Nordström

Fr.: tou noir de Reissner-Nordström   

A type of electrically charged → black hole that is spherically symmetric and non-rotating. Another type of such objects is the → Kerr-Newman black hole.

Named after the German physicist Hans Jacob Reissner (1874-1967) in 1916 and the Finnish Gunnar Nordstrom (1881-1923) in 1918 independently worked out solutions different from those of Schwarzschild; → black hole.

rotating black hole
  سیه‌چال ِ چرخان   
siyahcâl-e carxân

Fr.: trou noir en rotation   

A black hole that possesses angular momentum, as first postulated by Roy C. Kerr in 1963. Opposite of a stationary black hole. → ergosphere.

rotating; → black hole.

Schwarzschild black hole
  سیه‌چال ِ شو‌آرتسشیلد   
siyahcâl-e Schwarzschild

Fr.: trou noir de Schwarzschild   

A → black hole with zero → angular momentum (non-rotating) and zero electric charge derived from Karl Schwarzschild 1916 exact solution to Einstein's vacuum → field equations.

Karl Schwarzschild (1873-1916), German mathematical physicist, who carried out the first relativistic study of black holes. → black hole.

second law of black-hole mechanics
  قانون ِ دوم ِ مکانیک ِ سیه‌چال   
qânun-e dovom-e mekânik-e siyah-câl

Fr.: deuxième loi de la mécanique des trous noirs   

The surface area of a black hole's horizon can never decrease.

second; → law; → black hole; → mechanics.

stationary black hole
  سیه‌چال ِ ایست‌ور   
siyah-câl-e istvar

Fr.: trou noir stationnaire   

A → black hole with zero → angular momentum, that does not rotate.

stationary; → black hole.

stellar black hole
  سیه‌چال ِ ستاره‌ای   
siyah câl-e setâre-yi

Fr.: trou noir stellaire   

A → black hole with a mass in the range 3-30 → solar masses representing the end-product of → massive star evolution. Since → neutron stars cannot have masses larger than 3 solar masses, compact objects more massive than this must be black holes. There is good observational evidence for the existence of stellar black holes, based in particular on dynamical measurements of the masses of compact objects in → transient X-ray sources. Same as → stellar-mass black hole.

stellar; → black; → hole.

stellar-mass black hole
  سیه‌چال با جرم ِ ستاره‌ای   
siyah câl bâ jerm-e setâre-y

Fr.: trou noir de masse stellaire   

Same as → stellar black hole.

stellar; → mass; → black; → hole.

supermassive black hole (SMBH)
  سیه‌چال ِ اَبَر-پرجرم   
siyahcâl-e abar-porjerm

Fr.: trou noir supermassif   

A → black hole of tremendous mass, equivalent to those of millions or even billions of stars, which is believed to exist and occupy the centers of many galaxies. The supermassive black hole residing in the center of our → Milky Way Galaxy is the object → Sgr A* with a mass of 4 x 106solar masses within a radius of 100 → astronomical units.

supermassive; → black hole.

Tholen classification
  رده‌بندی ِ تولن   
radebandi-ye Tholen

Fr.: classification de Tholen   

A fundamental system for the classification of → asteroids based on → albedo and → spectral characteristics. The Tholen scheme includes 14 types with the majority of asteroids falling into one of three broad categories, and several smaller types. → C-type asteroid, → M-type asteroid, → S-type asteroid.

David J. Tholen (1984) Ph.D. thesis, University of Arizona; → classification.

white hole
  سوراخ ِ سفید، سفید‌چال   
surâx-e sefid, sefid-câl

Fr.: trou blanc   

A hypothetical opposite of the → black hole, from which particles and light pour out. However, there is a basic problem with white holes. Contrarily to black holes, no physical processes justify their existence. The appearance of a white hole is not due to any cause, it is acausal.

white; → hole.

  کرم-سوراخ، سوراخ ِ کرم   
kerm-surâx, surâx-e kerm

Fr.: trou de ver   

A hypothetical topological feature, based on → general relativity, that connects two different points like a "tunnel" in → space-time. The most common concept of a wormhole is an → Einstein-Rosen bridge. A trip through the wormhole could take much less time than a journey between the same starting and ending points in normal space. Wormholes have various types, intra-universe wormholes (connecting two distant regions of our Universe with each other) and inter-universe wormholes (that connect our Universe with another universe).

The term was coined by the Princeton physicist John Wheeler (1911-2008), from worm, M.E., O.E. wurm "serpent, dragon;" cf. O.S., O.H.G., Ger. wurm, O.Fris., Du. worm, Goth. waurms "serpent, worm;" akin to Pers. kerm "worm," as below; → hole.

Kerm "worm;" Mid.Pers. kirm "worm, snake, dragon;" cf. Skt. krmi- "worm, maggot;" O.Ir. cruim "worm;" Lith. kirmis "worm;" L. vermis "worm;" E. worm, as above; surâx, → hole.

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