An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 954
attenuation coefficient
  همگر ِ تنکش   
hamgar-e tonokeš

Fr.: coefficient d'bsorption   

The fraction of a beam of → X-rays or → gamma rays that is absorbed or scattered per unit thickness of the → absorber. The linear attenuation coefficient, denoted by the symbol μ, appears in the equation I(x) = I0ex, where I(x) is the intensity at depth of x cm and I0 is the original intensity.

attenuation; → coefficient.

attenuation factor
  کروند ِ تنکش   
karvand-e tonokeš

Fr.: facteur d'atténuation   

The ratio of the radiation intensity after traversing a layer of matter to its intensity before.

attenuation; → factor.

ruykard (#)

Fr.: attitude   

Position of a satellite with respect to the horizon or some other fixed reference plane.

Fr., from It. attitudine "disposition, posture," from L.L. aptitudo "faculty."

Ruykard, noun from ruy kardan "to turn the face toward," from ruy "face" (Mid.Pers. rôy, rôdh "face," Av. raoδa- "growth," in plural "appearance," from raod- "to grow, sprout, shoot," cf. Skt. róha- "rising, height") + kardan "to do, make, perform" (Mid.Pers. kardan, O.Pers./Av. kar- "to do, make, build," Av. kərənaoiti "makes," cf. Skt. kr- "to do, to make," krnoti "makes," karma "act, deed;" PIE base kwer- "to do, to make").



Fr.: atto-   

A prefix meaning 10-18.

From Danish or Norwegian atten "eighteen," from O.N. attjan "eighteen," from atta "eight" (compare with Gk. okto, L. octo, Skt. astau, Av. ašta-, Mod.Pers. hašt; PIE *okt(u)) + tjan "ten" (compare with Skt. dasa, Av. dasa, Mod.Pers. dah, Gk. deka, L. decem; PIE *dekm).

darkašidan (#)

Fr.: attirer   

To cause to draw near or adhere by physical force.

L. attractus, p.p. of attrahere "to draw, to attract," from ad- "to" + trahere "to pull, draw."

Darkašidan, from dar- "in, into" + kašidan "to draw, attract," → galaxy.


Fr.: attraction   

The act or capability of attracting. A physical force (gravitational, electric, magnetic, etc.) exerted by material bodies.

Attraction, n. from → attract.

darkašandé (#)

Fr.: attractif   

Having the quality of attracting.

Verbal adj. from → attract.

attractive force
  نیروی ِ درکشنده   
niru-ye darkašandé

Fr.: force attractive   

A physical force (→ gravitational, → electric, → magnetic, etc.) by which a body attracts another.

attractive; → force.


Fr.: attracteur   

The physical body that attracts. → Great Attractor.

attract; → -or.

  ۱) آباژ، آباژه؛ ۲) آباژیدن   
1, 2) âbâž, âbâžé; 3) âbâžidan

Fr.: 1, 2) attribut; 3) attribuer   

1) General: Something attributed as belonging to a person, thing, or group; a quality, characteristic, or property.
2) Computer science: A characteristic that describes an → entity.
3) To explain as resulting from a specified cause; to regard as caused by something indicated.

M.E., from L. attributus, p.p. of attribuere "to assign to, add, bestow;" figuratively "to attribute, ascribe, impute," from → ad- "to" + tribuere "to pay, assign, give, bestow," → distribute.

Âbâž, âbâžé, from â- strength or nuance prefix + bâž "tribute, toll, impost," → distribute.


Fr.: aubrite   

A type of → achondrite meteorite composed mostly of the magnesium silicate mineral → enstatite (Mg2Si2O6). The group is named for the small Aubres → meteorite that fell near Nyons, France, on Sep. 14, 1836. Outside Antarctica only about 10 aubrites are known, mostly the result of witnessed falls. Aubrites make up only 0.14% of all known meteorites in our terrestrial meteorite collection.

From Fr. Aubres, a commune in the Drôme department in southeastern France; + → -ite.

Auger electron
  الکترون ِ اژه   
elektron-e Auger

Fr.: électron d'Auger   

An electron that is emitted when an electron from a higher → energy level falls into a → vacancy in an inner shell, according to the → Auger-Meitner effect. The process usually occurs when the atom is bombarded with high energy electrons. If the collision ejects an inner-shell electron, an electron from a higher level will quickly drop to this lower level to fill the vacancy. Most of the time, the energy is released in the form of a photon. But sometimes the energy is transferred to another electron, which is ejected from the atom.

Auger-Meitner effect; → electron.

Auger-Meitner effect
  اسکر ِ اژه-مایتنر   
oskar-e Auger-Meitner

Fr.: effet Auger-Meitner   

The → emission of an → electron when an → atom transits to a less → excited state. More specifically, → ionization of an atom by a very energetic photon can bring about the ejection of an inner electron of the atom. Consequently, the atom becomes unstable and rapidly undergoes a → spontaneous transition. As a result, an outer electron moves inward and fills the → vacancy produced in the inner orbit. Energy conservation requires that this transition be accompanied by the emission of a photon or a peripheral electron. The latter is called the → Auger electron. Knowing the electron energy leads us to characterize the atom from which it was ejected. This effect is used, in the Auger spectroscopy, to analyze the surface compositions of materials.

This effect was discovered in 1923 Lise Meitner (1878-1968) and in 1925 independently by Pierre Auger (1899-1993).

  ارابه‌ران، گردونه‌ران   
Arrâbe-rân, Gardune-rân

Fr.: Cocher   

The Charioteer. A conspicuous northern constellation lying midway between → Perseus and → Ursa Major and in a region crossed by the → Milky Way. The brightest star is → Capella. Auriga is the site of the Galactic → anticenter. Abbreviation: Aur; genitive form: Aurigae.

L. auriga "a charioteer, driver," from aureæ "bridle of a horse" + agere "set in motion, drive, lead."

Arrâberân "charioteer," from arrâbé "chariot, cart" + rân "driver," from rândan "to drive." Arrâbé probably from *arâba, from *râba, from *râda, compare with Av. ratha- "chariot," akin to Skt. rathah "car, chariot," L. rota "wheel," rotare "revolve, roll," Lith. ratas "wheel," O.H.G. rad, Ger. Rad, Du. rad, O.Ir. roth; PIE *roto- "to run, to turn, to roll."
Gardunerân "a charioteer," from garduné "chariot, car," from gardun "wheel; heaven," from gardidan "to turn, revolve."


Fr.: aurore   

A phenomenon consisting of luminous colorful arcs, rays, and streamers that appear in the Earth's upper atmosphere during the night with the greatest frequency in the northern and southern polar magnetic zones. This → non-thermal radiation is caused by the emission of light from atoms excited by electrons accelerated along the planet's magnetic field lines at the magnetic poles. Fluorescent emission from atomic oxygen at 5557 Å results in a greenish glow, and there is a weaker effect from the red line at 6300 Å. Blue and purple colors are emitted by atomic and molecular nitrogen.

L. Aurora, the Roman goddess of dawn, akin to Av. uš-, ušah- "dawn," Skt. usas-, usah- "dawn," Gk. eos "dawn," Lith. ausra "dawn," O.E. east "east," PIE *ausus- "dawn," from *aus- "to shine."

Ušé, from Av. uš-, ušah-, as above.

aurora australis
  اوشه‌ی ِ دشتری   
uše-ye daštari

Fr.: aurore australe   

The aurora in the Southern hemisphere, also called as Southern Lights.

aurora; → south.

aurora borealis
  اوشه‌ی ِ هودری   
uše-ye hudari

Fr.: aurore boréale   

The aurora in the Northern hemisphere, also called as Northern Lights.

aurora; → north.


Fr.: auroral   

Pertaining to the → aurora phenomenon.

aurora; → -al.

auroral emission
  گسیل ِ اوشه‌ای   
gosil-e uše-yi

Fr.: émission aurorale   

The → electromagnetic radiation emitted in planetary atmospheres involving the → aurora phenomenon.

auroral; → emission.

auroral line
  خط ِ اوشه‌ای   
xatt-e uše-yi

Fr.: raie aurorale   

1) A prominent → forbidden line in the spectra of the aurora at wavelengths of 5577 and 6300 Å giving the aurora its characteristic green and red colors. Both are emitted by atomic oxygen, the former in its transition from the second lowest excited electronic state (1S) to the lowest excited electronic state (1D), the latter in its transition from the lowest excited electronic state (1D) to the atomic ground state (3P).
2) A forbidden line emitted by interstellar ionized gas by several atomic species (O, O+, O++, N+, S++, etc.) corresponding to the transition from the state 1S to 1D. → forbidden line; → nebular line; → transauroral line.

auroral; → line.

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