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: 634
extinction coefficient
  همگر ِ خاموشی   
hamgar-e xâmuši

Fr.: coefficient d'extinction   

Gradient of apparent magnitude with air mass.

extinction; → coefficient.

extinction correction
  ارشایش ِ خاموشی   
aršâyeš-e xâmuši

Fr.: correction d'extinction   

In → photometric calibration, the correction for energy loss undergone by radiation due to the → atmospheric extinction. Extinction correction is done using → standard stars observed at different → airmasses.

extinction; → correction.

extinction curve
  خم ِ خاموشی   
xam-e xâmuši

Fr.: courbe de l'extinction interstellaire   

A graph representing the variation of the → interstellar extinction against → wavelength. Usually it displays the → normalized values of extinction as a function of (the → inverse) of the wavelength (in → microns). See, e.g., Sandage & Mathis, 1979, Ann. Rev. Astron. Astrophys. 17, 73.

extinction; → curve.

extinction stars
  ستارگان ِ خاموشی   
setâregân-e xâmuši

Fr.: étoiles d'extinction   

Stars specifically observed at selected air masses in view of determining the atmospheric extinction coefficients.

extinction; → star.

extra-
  استر-، برون-   
ostar-, borun- (#)

Fr.: extra-   

Prefix meaning "outside; beyond the scope of; in addition to what is used or expected." Also extro-.

M.E., from L. extra, adverb and preposition, "outside, except, beyond," from exter "outward, on the outside."

Ostar-, from os-, → ex-, + -tar comparative suffix (Mid.Pers. -tar; Av. -tara; PIE base *-tero); borun-, from borun "out, the outside" (Mid.Pers. bêron, from "outside, out, away" + rôn "side, direction;" Av. ravan- "(course of a) river").

extragalactic
  استرکهکشانی، برون‌کهکشانی   
ostar-kahkašâni, borun-kahkašâni

Fr.: extragalactique   

Of, pertaining to, or dealing with the space beyond the Milky Way.

From → extra- + → galactic.

extragalactic astronomy
  اخترشناسی ِ استرکهکشانی، ~ برون‌کهکشانی   
axtaršenâi-ye ostar-kahkašâni, ~ borun-kahkašâni

Fr.: astronomie extragalactique   

The branch of astronomy that deals with objects beyond the Milky Way, especially galaxies and quasars.

extragalactic; → astronomy.

extragalactic background light (EBL)
  نور ِ پس-زمینه‌ی ِ استر-کهکشانی   
nur-e paszimine-ye ostarkahkeši

Fr.: lumière du fond extragalactique   

The integrated intensity of all of the light emitted throughout the history of the Universe across the whole of the → electromagnetic spectrum, including those which are not individually detected. The EBL spectrum includes cosmological backgrounds associated with either primordial phenomena, such as the → cosmic microwave background radiation (CMBR), or photons emitted by stars, galaxies and → active galactic nuclei (AGN) due to → nucleosynthesis or other → radiative processes, including → dust scattering, → absorption and reradiation. The EBL may also contain signals that are diffuse and extended, including high-energy photons associated with dark matter particle decays or annihilation.

extragalactic; → background; → light.

extraordinary
  استرشونیک   
ostaršunik

Fr.: extraordinaire   

1) Beyond what is usual, ordinary, regular, or established.
2) Exceptional in character, amount, extent, degree, etc. (Dictionary.com). → unordinary.

extra-; → ordinary.

extraordinary ray
  پرتو ِ استرشونیک   
partov-e ostaršunik

Fr.: rayon extraordinaire   

When a beam of → unpolarized light is incident on a → doubly refracting crystal, there will be two refracted rays. The ray for which → Snell's law does not hold.

extraordinary; → ray.

extrapolate
  برون‌یافتن   
borunyâftan (#)

Fr.: extrapoler   

Math.: To estimate the value of a result outside the range of a series of known values.

From → extra- + (inter)polate, → interpolate.

From borun, → extra- + yâftan, yâbidan "to find, discover; to obtain, acquire;" Mid.Pers. ayâftan, ayâpênitan "to reach, attain;" Manichean Mid.Pers. 'y'b "to attain;" Parthian, Sogdian (+ *pati-) pty'b "to reach, obtain;" Av. ap- "to reach, overtake," apayeiti "achieved, reached;" Skt. âp- "to reach, gain," âpnoti "reaches, gains;" Gk. hapto, haptomai "to touch, cling to, adhere to;" L. apiscor "touch, reach;" PIE base *ap- "to take, reach."

extrapolation
  برون‌یابش   
borunyâbeš (#)

Fr.: extrapolation   

Predicting the value of unknown data points by projecting a function beyond the range of known data points.

Verbal noun of → extrapolate.

extrasolar
  اُسترخورشیدی   
ostarxoršidi

Fr.: extrasolaire   

Not belonging to the → solar system; outside, or originating outside, the solar system.

extra-; → solar.

extrasolar planet
  سیاره‌ی ِ اُسترخورشیدی   
sayyâre-ye ostarxoršidi

Fr.: planète extrasolaire   

A planet which belongs to a star other than → Sun, and therefore does not belong to our → solar system; same as → exoplanet.

extrasolar; → planet.

extraterrestrial
  اُسترزمینی   
ostarzamini

Fr.: extraterrestre   

1) (adj.) Of or from outside the limits of the Earth.
2) (n.) A hypothetical extraterrestrial being; → alien.

extra- + → terrestrial.

extreme
  استوم   
ostom

Fr.: extrême   

Farthest from the center or middle; outermost; exceeding the bounds of moderation. → extreme adaptive optics; → extreme HB star; → extreme horizontal branch star; → extreme infrared; → extreme mass ratio inspiral; → extreme ultraviolet; → extremely metal-poor star.

From L. extremus "outermost, utmost," superlative of exterus, "outer," comparative of ex "out of," → ex-.

Ostom "outermost, utmost" (Av. (ustəma- "outermost, highest, ultimate"), superlative of ost "out," → ex-, + -tom superlative suffix, from Mid.Pers. -tom (xwaštom "most pleasant," nevaktom "best," wattom "worst"), from O.Pers. -tama- (fratama- "first, front"); Av. -təma- (amavastəma- "strongest," hubaiδitəma- "most sweet-scented," baēšazyôtəma- "most healing," fratəma- "first, front"); cf. Skt. tama-.

extreme adaptive optics
  نوریک ِ نیاوشی ِ استوم   
nurik-e niyâveši-ye ostom

Fr.: optique adaptative extrême   

An → adaptive optics system with high-contrast imaging and spectroscopic capabilities. Extreme adaptive optics systems enable the detection of faint objects (e.g., → exoplanets) close to bright sources that would otherwise overwhelm them. This is accomplished both by increasing the peak intensity of point-source images and by removing light scattered by the atmosphere and the telescope optics into the → seeing disk.

extreme; → adaptive; → optics.

extreme HB star
  ستاره‌ی ِ EHB   
setâre-ye EHB

Fr.: étoile EBH   

Same as → extreme horizontal branch star.

extreme horizontal branch star.

extreme horizontal branch star (EHB)
  ستاره‌ی ِ شاخه‌ی ِ افقی ِ استوم   
setâre-ye šâxe-ye ofoqi-ye ostom

Fr.: étoile de la branche horizontale extrême   

The hottest variety of stars on the → horizontal branch with temperatures ranging from 20,000 to 40,000 K. EHB stars are distinguished from normal horizontal branch stars by having extremely thin, inert hydrogen envelopes surrounding the helium-burning core. They are hot, dense stars with masses in a narrow range near 0.5 Msun. These stars have undergone such extreme mass loss during their first ascent up the giant branch that only a very thin hydrogen envelope survives. Stars identified as EHB stars are found in low metallicity globular clusters as an extension of the normal HB.

extreme; → horizontal; → branch; → star.

extreme infrared
  فروسرخ ِ استوم   
forusorx-e ostom

Fr.: infrarouge extrême   

A portion of the far infrared radiation, including wavelengths between 100 and 1,000 microns.

extreme; → infrared.

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