An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 160 Search : and
diffuse interstellar band (DIB)
  باند ِ پخشیده‌ی ِ اندر‌اختری   
bând-e paxšide-ye andaraxtari

Fr.: bande diffuse interstellaire   

Absorption features in the spectrum of stars identified in the ultraviolet, visible, and infrared regions. They have an interstellar origin, but despite extensive efforts, their carrier(s) have not yet been clearly identified. See also → Aromatic Infrared Bands; → polycyclic aromatic hydrocarbons.

diffuse; → interstellar; → band.

diffuse interstellar band carrier
  برنده‌ی ِ باند ِ پخشیده‌ی ِ اندر‌اختری   
barande-ye bând-e paxšide-ye andaraxtari

Fr.: porteur des bandes diffuses interstellaires   

The chemical element or composition that is supposedly at the origin of a → diffuse interstellar band (DIB).

diffuse; → interstellar; → band; → carrier.

emission band
  باند ِ گسیلی   
bând-e gosili

Fr.: bande d'émission   

In a spectrum, a combination of several closely spaced, often unresolved, → emission lines occurring across a limited range of wavelengths.

emission; → band.

ever-expanding Universe
  گیتی ِ هماره‌سپانا   
giti-ye hamâré sopânâ

Fr.: Univers en expansion continue   

Same as → accelerating Universe.

expand; → Universe.

  ۱) سپاندن؛ ۲) سپانده شدن   
1) sopândan; 2) sopânde šodan

Fr.: 1) dilater, agrandir, développer; 2) se dilater, s'agrandir, se développer   

1a) To change (something) from a smaller form and/or size to a larger one.
1b) To increase the extent, number, volume or scope of (something).
1c) To express (something) at length and/or in detail.
1d) Math.: To write (a mathematical expression) as a sum of terms in an extended form.
2) to increase or grow in extent, bulk, scope; to spread out; unfold; develop.
See also → spread, → extend, → dilate.

M.E. expanden, from O.Fr. espandre "to spread, spread out," from L. expandere "to spread out, unfold, expand," from → ex- "out" + pandere "to spread, stretch," from nasalized form of PIE root *pete- "to spread," a Pers. offshoot of which is pahn "wide, broad," as below. from

Sopândan, "to stretch, to extend, open out" from so- "out," → ex-, + pân, from pan, variant of pahn "wide, large, broad, ample, extensive," from Mid.Pers. pah(a)n; Av. paθana- "broad, wide, spacious;" PIE root *pete- "to spread;" cf. L. patere "to be open," Gk. petannynai "to spread out," petalon "a leaf."
Alternatively, sopândan "to open up, to open out," from so- "out," → ex-, + pân "open," cf. Yaghnobi pen, peyn "to open, unroll," Sogd. pyn- "to open," ultimately from Proto-Ir. *apa- "off, away, from" + *hHai- "to chain, bind," from which Pers. gošâdan "to open, release" (Cheung 2007).

Expanded Very Large Array (EVLA)

Fr.: EVLA   

A → radio interferometer array consisting of 27 25-meter diameter antennas located on the Plains of San Agustin in West-Central New Mexico. EVLA will operate at any frequency between 1.0 and 50 GHz and will have a continuum sensitivity improvement over the → VLA by factors of 5 to 20.The EVLA project is expected to be completed in 2012. See also the EVLA homepage.

expand; → very; → large; → array.

expanding Universe
  گیتی ِ سپانا، ~ سپاننده   
giti-ye sopânâ, ~ sopânande

Fr.: Univers en expansion   

The deduction based on the observational fact that the greater the → distance to a → galaxy, the greater the → redshift in its → spectral lines (→ Doppler effect). The observations strongly indicate that galaxies appear to be moving away from us with speeds proportional to their distance. This is in agreement with the overall → expansion of the → Universe.

expand; → -ing; → Universe.

forbidden band
  باند ِ بژکم   
bând-e bažkam

Fr.: bande interdite   

In → solid state physics, a range of → energy levels which is not attained by any electrons in a → crystal. In the energy level diagram forbidden bands appear as gaps between → allowed bands.

forbidden; → band .

frequency band
  باند ِ بسامد   
bând-e basâmad

Fr.: bande de fréquence   

A range of frequencies that is continuous between two specified limits, selected from a more extended range of frequencies.

frequency; → band.

G band
  باند ِ G   
bând-e G

Fr.: bande G   

A conspicuous band of molecular → CH (methylidine) at 4300 Å, which is present in the spectra of late-type G-K stars.

G refers to → G type stars in the spectra of which this feature is strong. → band.

grand design spiral galaxy
  کهکشان ِ مارپیچ ِ فرساز   
kahkešân-e mârpic-e farsâz

Fr.: galaxie spirale parfaite   

A galaxy with prominent → arms that are clearly attached to the central → bulge or → bar spiraling continuously outward until they reach the edge of the visible disk. Some examples are: → Whirlpool galaxy (M51), M74 (NGC 628), and NGC 2997.

M.E. graunt, from O.Fr. grant, grand, from L. grandis "big, great," also "full-grown;" design, from M.E. designen, from L. designare "mark out, designate, appoint," from → de- "out" + signare "to mark," from signumsign; → spiral; → galaxy.

Kahkešân, → galaxy; mârpicspiral; farsâz, → perfect.

grand unified theory (GUT)
  نگره‌ی ِ یگانش ِ بزرگ   
negare-ye yegâneš-e bozorg (#)

Fr.: théorie de la grande unification   

Any physical theory that unites the strong, electromagnetic, and weak interactions at high energy. It is hoped that GUTs can ultimately be extended to incorporate gravity. → theory of everything.

M.E. graunt, from O.Fr. grant, grand, from L. grandis "big, great," also "full-grown;" unified, p.p. of → unify; → theory.

Negâré, → theory; yegâneš, verbal noun of yegânestan, → unify; bozorggreat.

H and K lines
  خطهای ِ H و K   
xatthâ-ye H o K

Fr.: raies H et K   

Two prominent → absorption lines, at 3968.5 Å and 3933.7 Å respectively, in the spectra of stars like the → Sun and cooler due to → singly ionized → calcium (Ca II). The strength of H and K lines can be an indication of considerable magnetic activity in the → chromosphere of these stars. The Ca II H and K lines are also common in some kinds of → eruptive variable stars. These lines are not seen in → hot stars, and start to become visible in → A-type stars.

H and K, letters of alphabet, conventionally chosen; → line.

dast (#)

Fr.: main   

1) The terminal part of the forelimb in humans and other primates.
2) A part serving the function of or resembling a hand.

M.E. O.E. hond, hand "hand; side; power;" cf. O.S., O.Fris., Du., Ger. hand, O.N. hönd, Goth. handus.

Dast "hand; strength; superiority;" Mid.Pers. dast; O.Pers. dasta-; Av. zasta-; cf. Skt. hásta-; Gk. kheir; L. praesto "at hand;" Arm. jern "hand;" Lith. pa-žastis "arm-pit;" PIE *ghes-to-.

dastnâmé (#)

Fr.: manuel   

A scholarly book on a specific subject that is conveniently handled.

hand; → book.


Fr.: latéralité, manualité   

1) A tendency to use one hand rather than the other.
2) The property of an object (as a molecule) of not being identical with its mirror image. Same as → chirality (
See also: → B-mode polarization, → E-mode polarization.

hand + -ed + → -ness.

Dastâli, from dast, → hand, + -al, → -al, + noun suffix -i, on the model of → chirality.

Hartley band
  باند ِ هارتلی   
bând-e Hartley

Fr.: bande de Hartley   

A band in the → absorption spectrum of → ozone (O3) extending in the → ultraviolet from 200 nm to 300 nm. It is stronger than the → Huggins band. See also: → Hartley band.

W. N. Hartley, J. Chem. Soc. 39, 111 (1881).

kuhsâr (#)

Fr.: région montagneuse, hauts plateaux   

A mountainous or elevated region; → plateau.

high; → land.

Kuhsâr "mountainous, hilly area," from kuh, → mountain, + -sâr suffix denoting profusion, abundance, variant -zâr, → catastrophe.

Hubble-Sandage classification
  رده‌بندی ِ هابل-سندیج   
radebandi-ye Hubble-Sandage

Fr.: classification de Hubble-Sandage   

Same as the → Hubble classification.

Hubble; → Hubble-Sandage variable; → sequence.

Hubble-Sandage variable
  ورتنده‌ی ِ هابل-سندیج   
vartande-ye Hubble-Sandage

Fr.: variable de Hubble-Sandage   

A type of highly luminous → blue supergiant star with variable light, first discovered in the M31 and M33 galaxies; also called → S Doradus stars. They are now believed to be part of the class of → Luminous Blue Variable stars.

Hubble; Allan Rex Sandage (1926-2010), American cosmologist.

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