An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 41 Search : a-
šeš- (#)

Fr.: hexa-   

A prefix meaning → six. → hexagon.




A prefix meaning "below," used with second elements of any origin. → infrared; → infrasound.

From L. infra "below, underneath, beneath," from PIE *ndher; cf. Mod.Pers. zir "below, down," akin to → under-.

Foru-, from foru "down, downward; below; under, beneath; low," from Mid.Pers. frôt "down, downward;" O.Pers. fravata "forward, downward;" cf. Skt. pravát- "a sloping path, the slope of a mountain."

  درون-، در-؛ فرو-   
darun- (#), dar- (#); foru- (#)

Fr.: intra-   

Prefix denoting: "inside, within; below." → intramolecular forces; → intermolecular forces; → intramercurian planet.

From L. intra "on the inside, within; during; below." Commonly opposed to → extra-.

Darun "in, into; within" (Mid.Pers. andarôn "inside," from andar, → inter-, + rôn "side, direction;" Av. ravan- "(course of a) river").
Dar "in, into; within," from Mid.Pers. andar, → inter-.
Foru "down, downward; below; beneath" (Mid.Pers. frôt "down, downward;" O.Pers. fravata "forward, downward;" cf. Skt. pravát- "a sloping path, the slope of a mountain").

megâ- (#)

Fr.: méga-   

1) Prefix, often meaning "large, great."
2) Prefix meaning 106.

From Gk. megas "great, large, mighty," from PIE *meg- "great;" cf. L. magnus, Goth. mikils, O.E. micel.

matâ- (#)

Fr.: méta-   

A prefix appearing in loanwords from Gk., with the meanings 1) "after, behind;" 2) "changed, altered;" 3) "higher, beyond." → metagalaxy; metaphysics; → metastable.

From Gk. meta (prepositin) "in the midst of, among, with, after," originally me-ta (Mycenaean Greek), from PIE *me- "in the middle" (cf. Goth. miþ, O.E. mið "with, together with, among," E. with).

Matâ-, from Av. matay-, mati- "protrusion of mountain range," framanyente "to be protruding, jutting;" from PIE base *men- "to stand out, to project;" cf. L. mons (genitive montis) "mountain," minere "to project, jut, threaten" (other related terms: mouth, prominent, amount, etc.).

octa-, oct-
  هشت-، اکتا-، اکت-   
hašt-, octa-, oct-

Fr.: octa-, octo-, oct-   

A prefix meaning eight.

From L. octo, Gk. okto, cognate with Pers. hašt, as below. Skt. asta, Goth. ahtau, O.E. eahta (see eight).

Hašt "eight," from Mid.Pers. hašt, O.Pers.*aštahva- "eighth;" Av. ašta; cf. Skt. astā; Ossetic ast; (Buddhist) Sogdian 'št; Gk. okto, L. octo (Fr. huit; Sp. ocho); P.Gmc. *akhto(u) (O.E. eahta, æhta, E. eight, O.N. atta, Ger. acht, Goth. ahtau); PIE base *oktô(u).
Octa-, oct, loaned Gk. forms, as above.

pârâ- (#), parâ- (#)

Fr.: para-   

1) A prefix occurring in loanwords from Gk. with the meanings "beside, alongside of, by, beyond."
2) Chemistry: A combining form designating the para (1, 4) position in the benzene ring.
Short for → parahydrogen.

From Gk. para-, from para (preposition) "beside, near, from, against, contrary to," cognate with Av. parā, as below; L. pro "before, for, in favor of," per- "through;" Goth. faur "along;" O.E. for- "off, away."

Pârâ-, parâ-, from O.Pers. parā (adv.) "along; forth;" Av. parā (adv.) "at first, in the first place; in former times, formerly;" also "away, aside;" cf. Skt. purā: "before, formerly;" cognate with Gk. para, as above.


Fr.: eau para   

The → water molecule in which the → nuclear spins of the constituent → hydrogen atoms are → antiparallel (→ parahydrogen). See also: → ortho-water.

para-; → water.

panj- (#)

Fr.: penta-   

Prefix denoting five, fivefold (e.g. pentacyclic, pentahedron, pentahydrate).

From Gk. pent-, penta-, combining forms from pente "five;" cognate with Pers. panj, E. five, as below.

Panj, from Mid.Pers. panj, Av. panca; cf. Skt. pánca; Gk. pente; L. quinque; O.E. fif, from P.Gmc. *fimfe (O.S. fif, O.H.G. funf); from PIE base *penkwe "five."

petâ- (#)

Fr.: péta-   

A prefix denoting 1015.

Of unknown origin.

soft gamma-ray repeater (SGR)
  بازگرشگر ِ پرتوهای ِ گامای ِ نرم   
bâzgaršgar-e partowhâ-ye gâmmâ-ye narm

Fr.: répéteur des rayons gamma mous   

Same as → soft gamma repeater (SGR).

soft; → gamma ray; → repeater.

  فراز، بالا، ابر-   
farâz, bâlâ, abar-

Fr.: supra-   

A prefix denoting "over, above, beyond, greater than."

From L. supra "above, over, before, beyond," → super-.

Farâz "above, up, upon," → height; bâlâ "above, up, high," → height; abar-, → super-.

supra-Eddington layer
  لایه‌ی ِ ابر-ادینگتونی   
lâye-ye abar-Eddingtoni

Fr.: couche super-eddingtonienne   

In some stellar models, particularly for evolved → massive stars, such as → red supergiants, → Luminous Blue Variables, and → Wolf-Rayet stars, an outermost layer of the stellar envelope where the luminosity might exceed the → Eddington limit. This is due to the → opacity peak produced by the variation in the ionization level of hydrogen in the outer → convective envelope, beneath the surface, of very luminous stars. The opacity peak generates supra-Eddington layers and density inversion. The high opacity decreases the Eddington luminosity in these layers, possibly to fainter levels than the actual stellar luminosity. As a result, the → radiative acceleration exceeds the → gravitational acceleration leading to → mass loss enhancement (see, e.g., A. Maeder, Physics, Formation and Evolution of Rotating Stars, Springer, 2009).

supra-; → Eddington limit; → layer.

supra-horizontal branch star
  ستاره‌ی ِ فراز ِ شاخه‌ی ِ افقی   
setâre-ye farâz-e šâxe-ye ofoqi

Fr.: étoile au-dessus de la branche horizontale   

A member of a rare class of objects found in → globular clusters to lie about one magnitude above and to the blue part of the → horizontal branch. These stars are identified as post → EHB stars on their way from to the → asymptotic giant branch.

supra-; → horizontal; → branch; → star.

tera- (T)
terâ- (#)

Fr.: tera-   

Prefix denoting one million million (1012).

From Gk. teras "monster."

cahâr- (#)

Fr.: tétra-   

Combining form meaning four.

From Gk. tetra-, combining form of tettares, tessares "four," cognate with Pers. cahâr, → four.

ultar- (#)

Fr.: ultra-   

A prefix occurring originally in loanwords from L., with the basic meaning "on the far side of, beyond, extremely."

From L. ultra- from ultra (adverb and preposition) "beyond, on the further side," from *ulter, from uls "beyond;" + *-ter suffix of comparative adj.; PIE base *al- "besides, other, beyond."

Ultar-, from Mid.Pers. ul "up, upward," ulêh "upward, above" (Av. ərəδuua- "upright, risen; cf. Skt. ūrdhvá- "high, above, elevated; Gr. orthos "set upright, straight;" L. arduus "high, steep;" → ortho-) + -tar suffix forming comparative adjectives (Mid.Pers. -tar; Av. -tara- (masculine); PIE base *-tero).

ultra-high-energy cosmic ray (UHECR)
  پرتوهای ِ کیهانی ِ اولتر-مه-کاروژ   
partowhâ-ye keyhâni-ye ultar-meh-kâruž

Fr.: rayons cosmiques de très haute énergie   

A particle belonging to the most energetic population of → cosmic rays with an energy above ~ 1020 → electron-volts. The UHECRs constitute a real challenge for theoretical models, because their acceleration requires extreme conditions hardly fulfilled by known astrophysical objects. See also → UHECR puzzle, → Greisen-Zatsepin-Kuzmin cutoff.

ultra- + → high-energy cosmic ray.

ultra-high-energy neutrino
  نوترینو‌ی ِ اولتر-مه‌کاروژ   
notrino-ye ultar-meh-kâruž

Fr.: neutrino ultra haute énergie   

A neutrino particle accelerated to energies above 1018 → electron-volts. They are produced by the interaction of → ultra-high-energy cosmic ray (UHECR)s with the → cosmic microwave background radiation. Also called → cosmogenic neutrinos. See also → Greisen-Zatsepin-Kuzmin limit.

ultra-; → high; → energy; → neutrino.

yotta- (Y-)

Fr.: yotta-   

A metric prefix denoting 1024.

On the model of → yocto-.

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