An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -le Lag lam lan Lar lat law lea lem lep Lib lig lin lin lin liq Lit loc log lon lou low lun lun Lym > >>

Number of Results: 495
  خط، خت   
xatt (#), xat (#)

Fr.: ligne   

1) A mark or stroke long in proportion to its breadth, made with a pen, pencil, or other tools.
2) Math.: A continuous extent of length, straight or curved, without breadth or thickness; the trace of a moving point.

M.E. li(g)ne "cord, rope, stroke, series," from O.E. line "rope, row of letters," partly from O.Fr. ligne, from L. linea "linen thread, string, line," from phrase linea restis "linen cord," from fem. of lineus (adj.) "of linen," from linum "flax, linen."

Xatt, xat, used also in Ar., but it has no Hebrew counterpart. Xat is probably of Iranian origin, from *kerš-/*xrah- "to draw, plow;" cf. Av. karš- "to draw; to plow," karša- "furrow;" Mid/Mod.Pers. kešidan, kašidan "to draw, protract, trail, drag, carry," dialectal Yaqnavi xaš "to draw," Qomi xaš "streak, stria, mark," Lori kerr "line;" cf. Skt. kars-, kársati "to pull, drag, plow;" Gk. pelo, pelomai "to move, to bustle;" PIE base kwels- "to plow."

line blanketing
  پتومندی ِ خط   
patumandi-ye xatt


In stellar atmosphere models, the effect of metallic lines on the atmospheric structure of stars. The additional opacities of thousands of metallic lines alter the radiative transfer, leading to changes in the temperature. The emergent spectrum is consequently modified.

line-blanketed model.

line blending
  توهم‌شد ِ خط‌ها   
tuhamešod-e xatthâ

Fr.: confusion de raies   

Mixing of two or more spectral lines of adjacent wavelengths into a broad, single line due to insufficient dispersion of the spectrograph.

line; → blend.

line blocking
  بند‌آری ِ خط‌ها   
bandâri-ye xatthâ

Fr.: blocage par raies   

Reduction of the radiative flux in a model atmosphere due to absorption by a large number of lines. Line blocking affects the radiative transfer, ionisation and temperature structures, and the atmosphere's hydrodynamics.

line; block, from M.E. blok "log, stump," from O.Fr. bloc "log, block," via M.Du. bloc "trunk of a tree."

Bandâri "blocking," from band âvardan "to block," from band "dam, tie, chain," from bastan "to bind, shut, close up" (Mid.Pers. bastan, band; Av./O.Pers. band- "to bind, fetter," banda- "band, tie;" cf. Skt. bandh- "to bind, tie, fasten," bandhah "a tying, bandage;" Goth bandi "that which binds;" O.Fr. bande, bende; O.E. bend; M.E. bende; E. band; PIE base *bendh- "to bind") + âvari verbal noun of âvardan "to cause, produce; to bring" (Mid.Pers. âwurtan, âvaritan; Av. ābar- "to bring; to possess," from prefix ā- + Av./O.Pers. bar- "to bear, carry," bareθre "to bear (infinitive)," bareθri "a female that bears (children), a mother;" Mod.Pers. bordan "to carry;" Skt. bharati "he carries;" Gk. pherein; L. fero "to carry").

line broadening
  پهنش ِ خط   
pahneš-e xatt

Fr.: élargissement de raie   

A widening of → spectral lines due to any of several factors, including the → Doppler broadening, → instrumental broadening, → microturbulence, → pressure broadening, → rotational broadening, the → Stark effect, and the → Zeeman effect.

line; → broadening.

line cooling
  سردش ِ خط   
sardeš-e xatt

Fr.: refroidissement dû aux raies   

In stellar atmosphere models, the decrease of temperature in the outer layers of atmosphere due to the escape of photons through optically thin metallic lines. Energy is transferred from the thermal pool to photons and is lost for the atmosphere, leading to a temperature decrease.

line; → cooling.

line identification
  ایدانش ِ خط   
idâneš-e xatt

Fr.: identification de raies   

The process of recognizing the spectral lines in a spectrum.

line; → identification.

line intensity
  درتنویی ِ خط   
dartanuyi-ye xatt

Fr.: intensité de raie   

A measure of the total effect of an absorption or emission line. The line intensity is equal to the integration of the absorption coefficient over the entire shape of the absorption line.

line; → intensity.

line of action
  خط ِ ژیرش، ~ کنش   
xatt-e žireš, ~ koneš

Fr.: ligne d'action   

Of a force, the straight line along which the force → vector is directed. The action of a force on a → rigid body does not change when its point of application is displaced along the line of action. Hence, forces applied to a rigid body can be regarded as non-localized, or sliding, vectors.

line; → action.

line of apsides
  خط ِ هباک‌ها   
xatt-e habâkhâ

Fr.: ligne des apsides   

Of an elliptical orbit, the straight line drawn from the → perigee to the → apogee.

line, → apsides.

line of equinoxes
  خط ِ هموگان‌ها   
xatt-e hamugânhâ

Fr.: ligne des équinoxes   

The intersection of the planes of ecliptic and celestial equator.

line; → equinox.

line of flow
  خط ِ تچان   
xatt-e tacân

Fr.: ligne d'écoulement   

Same as → streamline.

line; → flow.

line of force
  خط ِ نیرو   
khatt-e niru (#)

Fr.: ligne de force   

One of many → imaginary lines whose direction at all → points along its length is that of the electric or → magnetic field at those points. In → electric fields the lines of force are directed toward → negative charges and point away from → positive charges. In magnetic fields the lines of force are directed from the → north pole to the → south pole.

line; → force.

line of induction
  خط ِ درهازش   
xatt-e darhâzeš

Fr.: ligne d'induction   

Same as → line of force in a magnetic field.

line; → induction.

line of nodes
  خط ِ گره‌ها   
xatt-e gerehhâ (#)

Fr.: lignes des nœuds   

The line created by the intersection of the equatorial plane and the orbital plane.

line, → node.

line of sight
  خط ِ دید، دیدخط   
xatt-e did, didxatt (#)

Fr.: ligne de visée   

The imaginary straight line connecting the object and the objective lens of the viewing device.

line; → sight.

line profile
  فراپال ِ خط   
farâpâl-e xatt

Fr.: profil de raie   

The representation of a spectral line as produced by an observing instrument.

line, → profile.

line profile variability (LPV)
  ورتندگی ِ فراپال ِ خط   
vartandegi-ye farâpâl-e xatt

Fr.: variabilité du profil de raie   

The change in the shape of a → spectral line over time. For instance, in → Wolf-Rayet stars the line profile varying on time-scales of minutes to hours is attributed to → microturbulence.

line; → profile; → variability.

line spectrum
  بیناب ِ خطی   
binâb-e xatti (#)

Fr.: spectre de raies   

Spectrum consisting of discrete lines (emission or absorption), each corresponding to a particular wavelength, as opposed to a continuous spectrum.

line, → spectrum.

line strength
  زور ِ خط   
zur-e xatt

Fr.: intensité de raie   

Same as → line intensity.

line, → strength.

<< < -le Lag lam lan Lar lat law lea lem lep Lib lig lin lin lin liq Lit loc log lon lou low lun lun Lym > >>