An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 428
fluorite
  فلوءوریت   
fluorit

Fr.: fluorite, fluorine   

A → mineral composed of calcium fluoride, CaF2, also called → fluorspar, that is often → fluorescent under → ultraviolet light.

From fluor-, → fluorine, + → -ite.

fluorspar
  فلوءوریت   
fluorit

Fr.: fluorine   

Same as → fluorite.

From fluor-, → fluorine, + spar "a crystalline mineral."

flux
  شار   
šâr (#)

Fr.: flux   

The amount of energy, fluid, or particles passing in a given direction in a unit of time.

O.Fr. flux, from L. fluxus, p.p. of fluere "to flow," PIE base *bhleug- (cf. L. flumen "river;" Gk. phluein "to boil over, bubble up," phlein "to abound").

Šâr "outpouring of water, wine, etc.," šâridan "to flow (as rivers), with a great noise; to pour," âbšâr "waterfall;" saršâr "overflowing; brim-full;" Ossetic ægzælyn "to pour down;" Pashto zγâstəl/zγâl- "to swim;" Av. γžār- "to flow;" cf. Skt. ksar- "to flow;" Gk. phtheirein "to destroy, perish."

flux calibration
  کبیزش ِ شار   
kabizeš-e šârr

Fr.: calibration de flux   

The → calibration of the flux received by a detector in terms of absolute units.

flux; → calibration.

flux density
  چگالی ِ شار   
cagâli-ye šârr

Fr.: densité de flux   

Flux of radiation that falls on a detector per unit surface area of the detector per unit bandwidth of the radiation per unit time.

flux; → density.

flux unit
  یکای ِ شار   
yekâ-ye šârr

Fr.: unité de flux   

In radio astronomy, same as → jansky (symbol Jy), a unit of electromagnetic flux equivalent to 10-26 watts per square meter per Hertz.

flux; → density.

fly
  پرواز کردن، پروازیدن   
parvâz kardan (#), parvâzidan (#)

Fr.: voler   

To move through the air using wings. Travel through the air or outer space.

M.E. flien, O.E. fleogan; cognate with O.H.G. fliogan, Ger. fliegen, O.Norse fljuga.

Infinitive from parvâz, → flight.

flyby
  برواز   
barvâz

Fr.: survol   

A trajectory that takes a → space probe close to a Solar System body (planet, satellite, asteroid, comet) but does not permit it to enter an orbit about the body.

fly + by, from M.E., from O.E. be or bi, from P.Gmc. *bi "around, about" (cf. Du. bij, Ger. bei "by, at, near"), from *umbi, (cf. L. ambi "around, about," Gk. amphi "around, about," Skt. abhi "on both sides," Av. aibi, aiwi, O.Pers. aiby "to, against, in addition to," Mid.Pers. aw-, ab-, Mod.Pers. af- (as in afzudan "to increase, add," afruxtan "to inflame, kindle, blaze," afqân "lamentation, groaning, cires for help").

Barvâz, from bar- "on, up; upon, over," → on-, + vâz, as in parvâz, → flight.

focal
  کانونی   
kânuni (#)

Fr.: focal   

Of or relating to a focus; placed at or measured from a focus.

focus + → -al.

focal distance
  دورای ِ کانونی   
durâ-ye kânuni

Fr.: distance focale   

same as → focal length.

focal; → distance.

focal length
  درازای ِ کانونی   
derâzâ-ye kânuni

Fr.: longueur focale   

The distance between the optical center of a lens, or the surface of a mirror, and its focus.

focal; → distance.

focal plane
  هامن ِ کانونی   
hâmon-e kânuni

Fr.: plan focal   

A plane at right angles to the principal axis of a lens or mirror on which the best image is formed.

focal; → plane.

focal point
  نقطه‌ی ِ کانونی   
noqte-ye kânuni

Fr.: point focal   

Same as → focus.

focal; → point.

focal ratio
  وابر ِ کانونی   
vâbar-e kânuni

Fr.: rapport focal   

The ratio of the → focal length of a reflecting surface or lens to its effective diameter, i.e. to its → aperture. The smaller the focal ratio, the smaller the image scale and the more luminous the image for a given aperture.

focal; → ratio.

focal reducer
  کاهنده‌ی ِ کانونی، باز‌هازنده‌ی ِ ~   
kâhande-ye kânuni, bâzhâzande-ye ~

Fr.: réducteur focal   

An optical component or system for changing the image scale of a telescope to achieve a better match between the → seeing disk and the → pixel size.

focal; → reducer.

focus
  ۱) کانون؛ ۲) کانونیدن   
1) kânun; 2) kânunidan

Fr.: 1) foyer; 2) focaliser   

1) (n.) A point where parallel light rays from an object are gathered together by a lens or a concave mirror. It is the place where the clearest image of a distant object forms. Also called focal point. See also → focal distance.
2) (v.) To adjust the eyepiece or objective of a telescope so that the image is clearly seen by the observer.

From L. focus "hearth, fireplace," of unknown origin,

Kânun "hearth, fireplace."

focused
  کانونیده   
kânunidé

Fr.: focalisé   

Of an optical system, being in focus or brought into focus; adjusted to produce a clear image.

Past participle of → focus.

focusing
  کانونش   
kânuneš

Fr.: focalisation   

The act of bringing into focus.

Noun of → focus.

fog
  مه   
meh (#)

Fr.: brouillard   

A mass or layer of suspended water droplets or ice crystals near the surface of the earth, reducing visibility.

From Dan. fog "spray, shower, snowdrift," related to O.N. fok "snow flurry."

Meh "fog" (variants miq, mož, Tabari miyâ, Lori/Laki (kara) mozy, Ossetic mig/megæ), from Mid.Pers. mēq "cloud, mist," Av. mēγa- "cloud;" cf. Skt. meghá- "cloud, overcast weather;" Gk. omikhle "mist;" Lith. miglà "mist, haze;" PIE base *mighlā- "cloud."

fogbow
  مه‌کمان   
meh-kamân

Fr.: arc blanc   

A large, faintly colored, circular arc formed by light (usually sunlight) falling on cloud or fog. Also called → cloudbow.

fog; → bow.

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