An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -cl con for lin lin lin neb qua str > >>

Number of Results: 174 Search : line
contour line
  خط ِ پربند   
xatt-e parband

Fr.: contour   

A line joining points of equal elevation or on a surface or points of equal intensity in a map.

contour; → line.

cooling line
  خط ِ سردکننده، ~ سردگر   
xatt-e sardkonandé, ~ sardgar

Fr.: raie de refroidissement   

The spectral → emission line through which the → colling process takes place.

cooling; → line.

coronal line
  خط ِ هورتاجی   
xatt-e hurtâji

Fr.: raie coronale   

An → emission line in the spectrum of the → solar corona caused by highly ionized metal ions; especially those of iron, such as the red and green lines at 6375 Å and 5303 Å [Fe X] (Fe9+ ion) and [Fe XIV] (Fe13+ ion), respectively. From their discovery in 1870 until 1939, it was believed that these → forbidden lines would be due to an unknown element, called → coronium. Ultraviolet and X-ray coronal lines are also detectable in stars.

coronal; → line.

  بلوری، بلورین   
boluri, bolurin

Fr.: cristallin   

1) Of or like crystal; clear; transparent.
2) Formed by → crystallization.
3) Composed of crystals.
4) Pertaining to crystals or their formation (

Adjective from → crystal.

crystalline lens
  عدسی ِ چشم   
adasi-ye cašm (#)

Fr.: cristallin   

A → doubly convex, → transparent body in the → eye, situated behind the → iris, that focuses incident light on the → retina (

crystalline; → lens; → eye.

crystalline structure
  ساختار ِ بلورین   
sâxtâr-e bolurin

Fr.: structure cristalline   

An arrangement and interrelationship of parts that is of → crystalline nature.

crystalline; → structure.


Fr.: curviligne   

Consisting of, represented by, or bound by curved lines. → rectilinear.

From → curve + → linear.

D line
  خط ِ D   
xatt-e D

Fr.: raie D   

One of the pair of yellow lines in emission spectra of neutral sodium (Na I). D1 has a wavelength of 5895.94 Å and D2 is 5889.97 Å. This sodium doublet is one of the strongest absorption features in the spectra of late-type stars.

Labelled D in a sequence of alphabetical letters first used by Joseph von Fraunhofer to designate spectral features in the solar spectrum, → Fraunhofer line.

D3 line
  خط ِ D3   
xatt-e D3

Fr.: raie D3   

The → neutral → helium  → spectral line at 5876 Å.

D3, because of confusion with the sodium → D lines. When Joseph N. Lockyer first observed this line in the solar spectrum at the eclipse of 1868, helium was not yet isolated on Earth. Initially, this line was thought to be the third member of the D1 and D2 line family of sodium which lie in the same yellow part of the spectrum; → line.


Fr.: date limite, ~ boutoir, ~ de clôture   

The time by which something must be finished or submitted; the latest time for finishing something (

Historically, during the American Civil War, the term referred to a physical line or boundary beyond which prisoners were shot; → dead; → line.

Ruzband, literally "day lock, that which blocks date," from ruz, → day, + band, → bond; cf. Ger. Stichtag, Anmeldeschluss, Einsendeschluss and Fr. date de clôture.

  ۱) واکیلیدن؛ ۲) واکیل   
1) vâkilidan; 2) vâkil

Fr.: décliner, se décliner   

1a) To bend down; slope downward; descend.
1b) Grammar: To → inflect according to the various cases of a noun, adjective, or pronoun.
2) The process of declining; a downward movement; gradual loss or deterioration.

M.E. declinen, from O.Fr. decliner "to sink, decline, degenerate, turn aside," from declinare "to turn away, inflect," from → de- + clinare "to bend," cf. Gk. klinein "to cause to slope, slant, incline," Skt. sri- "to lean," O.Pers. θray-, Av. sray- "to lean," Mod.Pers. kil "bent, inclined, slant," PIE base *klei- "to lean, incline" from which is also derived (Ger. lehnen, E. lean).

Vâkil, from prefix vâ- "away" + kil "bent, crooked, inclined" [Dehxodâ], Mid.Pers. xwahl "bent, crooked" (Mod.Pers. dialectal/colloquial variants kowleh, cowleh, cowl, caval, xohl, xohal, hol), cf. Skt. kûla- "slope, declivity;" PIE base *klei-, as above. → inclination


Fr.: discipline   

1) A branch of learning or instruction.
2) A system of rules for behavior, methods of practice, etc.

M.E., from M.Fr. discipline, descepline, from L. disciplina literally "teaching, instruction," from discipulus "pupil, student, follower," from dis- + cipere, combining form of capere "to take," → concept, + -ulus, → -ule.

Hâvešân, from hâveš "disciple, pupil," Mid.Pers. hâvišt "disciple, pupil;" Av. hāvišta- "disciple, pupil," + -ân a suffix denoting "group, order, system."

double-lined binary
  دورین ِ دوخطه   
dorin-e doxatté

Fr.: binaire à double raies   

A → spectroscopic binary in which the → spectral lines of both stars are seen and the lines are alternatively double and single. Same as → SB2 binary. See also: → single-lined binary.

double; → line; → binary

double-lined eclipsing binary
  دورین ِ گرفتی ِ دوخطه   
dorin-e gerefti-ye doxatté

Fr.: binaire à éclipse à double raies   

A → double-lined spectroscopic binary whose → light curve is typical of an → eclipsing binary.

double; → line; → eclipsing; → binary.

double-lined spectroscopic binary
  درین ِ دوخطه‌ی ِ بیناب‌نماییک   
dorin-e doxatte-ye binâbnemâyik

Fr.: binaire spectroscopique à double raies   

Same as → double-lined binary.

double; → line; → spectroscopic; → binary.

emission line
  خط ِ گسیلی   
xatt-e gosili (#)

Fr.: raie d'émission   

A bright line in the electromagnetic spectrum of a radiating substance caused by emission at a particular wavelength.

emission; → line.

Euler line
  خط ِ اویلر   
xatt-e Euler

Fr.: droite d'Euler   

In any → triangle, the straight line on which always lie the → centroid, → circumcenter, and → orthocenter.

Euler; → line.

Euler's broken line
  خط ِ شکسته‌ی ِ اویلر   
xatt-e šekaste-ye Euler

Fr.: ligne brisée   

The line drawn in a coordinate plane connecting the approximate values of the solution of a → first-order differential equation.

Euler; → broken line.

fine-structure line
  خط با ساختار ِ نازک   
xatt bâ sâxtâr-e nâzok

Fr.: raie de structure fine   

A → spectral line whose → energy levels have a → fine structure. Examples are [C II] 157.7 μm (→ singly ionized carbon), [O III] 88 μm, and [Ne II] 12.8 μm.

fine; → structure; → line.

flow line
  خط ِ تچان   
xatt-e tacân

Fr.: ligne d'écoulement   

Same as → streamline.

flow; → line.

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