An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 551
Sebar (#)

Fr.: Triangle   

The Triangle. A small northern constellation between → Andromeda and → Aries, at 2h right ascension, 32° north declination. Its three brightest stars, of magnitudes 3.0, 3.4, and 4.0, form a small, elongated isosceles triangle. One of the constellations listed by Ptolemy. The famous → spiral galaxy → M33 lies in Triangulum. Abbreviation: Tri; genitive: Trianguli.


Triangulum Australe
  سه‌بر ِ دشتری   
Sebar daštari

Fr.: Triangle austral   

The Southern Triangle. A small constellation in the southern hemisphere, at 16h right ascension, 65° south declination, introduced by Johann Bayer (1603). Abbreviation: TrA; genitive: Trianguli Australe

traingle; Australe "southern," from auster "south wind," metaphorically extended to "south."

Sebar, → traingle; daštarisouthern.

Triangulum galaxy (M33)
  کهکشان ِ سه‌بر   
kahkešân-e sebar (#)

Fr.: galaxie du Triangle   

One of the prominent members of the → Local Group situated in the constellation → Triangulum. M33 is a type Sc → spiral galaxy seen nearly → face-on. It lies 2.8 million → light-years away and its diameter is 52,000 light-years. Also know as NGC 598.

Triangulum; → galaxy.

triatomic hydrogen molecular ion
  یون ِ مولکولی ِ سه‌اتمی ِ هیدروژن   
yon-e molekuli-ye se-atomi-ye hidrožen

Fr.: ion moléculaire d'hydrogène triatomique, H3+   

The hydrogen molecule composed of three atoms in which one of the atoms is ionized. The molecular ion H3+ plays a key role in the chemistry of gaseous → interstellar medium. It reacts efficiently with almost any neutral atom or molecule to initiate a network of ion-neutral reactions. It is responsible for producing molecules such as OH, CO, and H2O. The first detection of H3+ in the interstellar medium, via two closely spaced absorption lines (doublet) near 3.668 μm, were reported in two dense → molecular cloud cores along the lines of sight to the embedded → young stellar objects W33A and GL2136 (Geballe & Oka 1996). Since then H3+ has been detected in several molecular clouds. It is believed that H3+ forms via → cosmic ray → ionization of H2 producing H2+, which quickly reacts to another H2 molecule to form H3+ ( H2 + CR → H2+ and H2+ + H2→ H3+ + H + 1.7 eV).

Tri-, → three; → atomic; → hydrogen; → molecular; → ion.


Fr.: trichroïsme   

The property of some crystals of exhibiting three different colors when viewed from three different directions under white lights. → dichroism.

From Gk. tri- "three" + chroic, from chroma "color" + -ism.

Sefâmi, from se, → three, + fâm "color," + -i noun suffix.

Trifid Nebula
  میغ ِ سه‌پاره   
miq-e sepâré

Fr.: nébuleuse Trifide   

A large luminous H II hydrogen in the constellation → Sagittarius. Conspicuous dust lanes radiating from the center appear to divide the nebula in three lobes. It is a combined emission and reflection nebula, extending for nearly 30' on the sky. Also known as M20, NGC 6514.

Trifid, from L. trifidus "split in three," from → tri- + fidus "divided," from findere "to split;" → nebula.

Miqnebula; sepâré "split in three," from , → three, + pâré "piece, part, portion, fragment;" Mid.Pers. pârag "piece, part, portion; gift, offering, bribe;" Av. pāra- "debt," from par- "to remunerate, equalize; to condemn;" PIE *per- "to sell, hand over, distribute; to assigne;" cf. L. pars "part, piece, side, share," portio "share, portion;" Gk. peprotai "it has been granted;" Skt. purti- "reward;" Hitt. pars-, parsiya- "to break, crumble."

  ۱) ماشه؛ ۲) ماشیدن   
1) mâšé; 2) mâšidan

Fr.: 1) déclancheur; 2) déclancher   

1a) (n.) Anything, as an act or event, that serves as a stimulus and initiates or precipitates a reaction or series of reactions.
1b) In electronics, the signal or stimulus that initiates a → trigger circuit.
2) (v.) To initiate or precipitate (a chain of events, scientific reaction, psychological process, etc.).

Earlier tricker, from Du. trekker "trigger," from trekken "to pull," from M.Du. trecken (cf. M.L.G. trecken, O.H.G. trechan "to draw").

1) Mâšé "a trigger, tongs, pincers," of unknown origin.
2) Mâšidan, infinitive from mâšé, as above.

trigger circuit
  برقراه ِ ماشه‌ای   
barqrâh-e mâše-yi

Fr.: circuit déclancheur   

A circuit in which a specific predetermined action is initiated by an input pulse.

trigger; → circuit

triggered star formation
  دیسش ِ ماشه‌ای ِ ستاره   
diseš-e mâše-yi-ye setâré

Fr.: formation d'étoiles déclanchée   

The formation of second-generation stars in a → molecular cloud, as set off by the action of → massive stars. → sequential star formation; → radiation-driven implosion.

trigger; → star formation.


Fr.: trigonométrique, circulaire   

Relating to or used in → trigonometry. → trigonometric function.

trigonometry; → -ic.

trigonometric function
  کریای ِ سه‌برسنجیک   
karyâ-ye sebarsanjik

Fr.: fonction circulaire, ~ trigonomtérique   

A function of an angle, one of six functions (sine, cosine, tangent, cotangent, secant, and cosecant) that represent ratios of sides of right triangles. Also called circular function.

trigonometric; → function.

trigonometric parallax
  دیدگشت ِ سه‌برسنجی، ~ سه‌برسنجیک   
didgašt-e sebarsanji, ~ sebarsanjik

Fr.: parallaxe trigonométrique   

The → parallax of a nearby star (less than 300 → light-years) against the background of more distant stars resulting from the motion of the Earth in its orbit around the Sun.

trigonometric; → parallax.


Fr.: trigonométrie   

The branch of mathematics dealing with the relations of the sides and angles of triangles; also the various algebraic functions of these relations.

From N.L. trigonometria, from Gk. trigonon "triangle" (from tri-, → three, + gonia "angle," cognate with Pers. zânu "knee") + metron, → -metry.

Sebarsanji, from sebar, → trianle, + -sanji, → -metry.

trinitro- (#)

Fr.: trinitro-   

In composition, having three nitro groups (NO2), especially replacing hydrogen. → trinitrotoluene.

From L. tri-, a combining form meaning → three + nitro- a combining form used in the names of chemical compounds in which the nitro group is present.

trinitrotoluene (TNT)
  تری‌نیتروتولویءن (TNT)   
trinitrotoluen (#)

Fr.: trinitrotoluène (TNT)   

A yellow, solid chemical compound, that does not occur naturally in the environment. More specifically, 2,4,6-trinitrotoluene (C6H2(NO2)3CH3), is commonly known as TNT. It is an explosive extensively used in munitions and for demolitions.

trinitro- + → toluene.


Fr.: 1) trinôme; 2) trinomial   

1) A → polynomial that consists of three terms.
2) Of, pertaining to, or consisting of a trinomial.

tri- + nomial, short for → nomnial.

setâyi (#)

Fr.: triple   

Threefold; consisting of three parts. → triple alpha process; → triple conjunction; → triple point; → triple star.

M.E., from M.L. triplare "to triple," from L. triplus "threefold, triple," from tri-, → three, + -plus "-fold."

Setâyi, from setâ, from three + "fold, plait, ply; piece, part," Mid.Pers. tâg "piece, part."

triple alpha process
  فراروند ِ آلفای ِ سه‌تایی   
farâravand-e âlfâ-ye setâyi

Fr.: réaction triple alpha   

A chain of nuclear fusion reactions by which three helium nuclei (→ alpha particles) are transformed into → carbon. First two nuclei of helium collide, fuse, and form a nucleus of → beryllium: 4He + 4He ↔ 8Be, which is unstable and will decay back into two helium nuclei within a few 10-17 seconds. However, due to sufficiently high density and temperature in the stellar core, during a third collision between beryllium and helium, carbon is formed: 8Be + 4He → 12C + γ. The triple-alpha process is possible owing to the existence of the → Hoyle state. It is the main source of energy production in → red giants and → red supergiants in which the core temperature has reached at least 100 million K. Also called → Salpeter process.

triple; → alpha particle; → process.

triple conjunction
  هم‌ایستان ِ سه‌تایی   
hamistân-e setâyi

Fr.: conjonction triple   

A rare event involving a particularly intricate set of movements of two planets or a planet and a star where they meet each other three times in a short period either in opposition or at the time of inferior conjunction, if an inferior planet is involved. The visible movement of the planet or the planets in the sky is therefore normally prograde at the first conjunction, retrograde at the second conjunction and again prograde at the third conjunction.

triple; → conjunction.

triple point
  نقطه‌ی ِ سه‌گانه   
noqte-ye segâné (#)

Fr.: point triple   

The definite pressure and temperature at which all three phases of a substance coexist in → phase equilibrium. The triple point of water has a pressure of 4.58 mm of Hg and a temperature of 273.16 °K.

triple; → point.

Noqté, → triple; segâné, from three + -gâné suffix forming plural entities, from Mid.Pers. -gânag, -gâna.

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