An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 544
transverse gauge
  گز ِ تراگذر   
gaz-e tarâgozar

Fr.: jauge transverse   

Same as the → Coulomb gauge.

transverse; → gauge.

transverse mass
  جرم ِ تراگذر   
jerm-e tarâgozar

Fr.: masse transverse   

In special relativity theory, the mass when the acceleration of a body is perpendicular to its velocity: mt = m0 / [1 - (v/c)2]1/2, where m0 is the → rest mass, v is the velocity, and c the → velocity of light. The transverse mass is identical to the → relativistic mass. See also → longitudinal mass.

transverse; → mass.

transverse velocity
  تندای ِ تراگذر   
tondâ-ye tarâgozar

Fr.: vitesse transverse   

Same as → tangential velocity.

transverse; → velocity.

transverse wave
  موج ِ تراگذر   
mowj-e tarâgozar

Fr.: onde transversale   

A wave in which the vibration or displacement takes place in a plane at right angles to the direction of propagation of the wave; e.g. electromagnetic radiation. → longitudinal wave.

transverse; → wave.

transverse Zeeman effect
  اُسکر ِ زیمن ِ تراگذر   
oskar-e Zeeman-e tarâgozar

Fr.: effet Zeeman transverse   

The → Zeeman effect when observed at right angles to the orientation of the magnetic field. Un un-displaced line is observed along with a doublet, three lines in all, with the frequencies ν and ν ± Δν. The two displaced components correspond to a plane of → polarization parallel to the external magnetic field and the un-displaced line to a plane of polarization perpendicular to this field. → longitudinal Zeeman effect.

transverse; → Zeeman effect.

trapezium
  ذوزنقه   
zuzanaqé (#)

Fr.: trapèze   

A four-sided plane figure, no two sides of which are parallel.

L.L. trapezium, from Gk. trapezion "irregular quadrilateral," literally "a little table," diminutive of trapeza "table," from shortening of *tetrapeza, from → tetra- "four" + peza "foot, edge," related to pous, podos, Pers. , → foot.

Zuzanaqé, loan from Ar. dhuzanaqat.

Trapezium cluster
  خوشه‌ی ِ ذوزنقه   
xuše-ye zuzanaqé

Fr.: amas du Trapèze   

A star cluster located in the center of the → Orion Nebula whose four brightest stars form the vertices of a trapezoid. They are known as θ1 Ori A, B, C, and D and are of magnitude 6.7, 8.0, 5.1, and 6.7 respectively. They are packed in an area 22 arcseconds across (10,000 A.U.). The Trapezium stars are responsible for the illumination of the entire Orion Nebula. The principal and the most massive star of the group is θ1Ori C, a young main sequence → O star of type O6. The three others are → B stars. Almost all of the Trapezium stars are multiple: the most massive star θ1Ori C is double, the next massive star θ1Ori A is triple, θ1Ori B is at least quadruple, and θ1Ori D is apparently single.

trapezium; → cluster.

tree
  درخت   
deraxt (#)

Fr.: arbre   

1) A tall, woody perennial plant usually with a single trunk.
2) Math.: → factor tree.

M.E., from O.E. treo, treow "tree, wood," from P.Gmc. *trewan (cf. O.S. trio, O.N. tre, Goth. triu), from PIE *deru- "wood" (cf. Mod.Pers. dâr "tree;" O.Pers. dāruv- "wood;" Av. dāuru- "piece of wood, tree trunk;" Skt. dāru- "tree, wood;" Gk. drus "tree;" Serb. drvo "tree;" L. larix "larch tree;" Rus. drevo "tree, wood;" Pol. drwa "wood;" Lith. derva "pine wood;" O.Ir. daur, Welsh derwen "oak").

Deraxt "tree;" Mid.Pers. draxt "tree," two possible etymologies. A suffixed variant of dâr "tree," cognate with E. tree, as above. Alternatively, from Av. *draxta- "firmly stood, fixed" (as in handraxta-), from drang-, dranj- "to fix, fasten, strengthen, hold," dražaite "holds," infinitive drājnhe; cf. Khotanese drys- "to hold;" Sogdian drγ- "to hold;" Parthian Mid.Pers. drxs "to endure."

trend
  روال   
ravâl (#)

Fr.: tendance   

A general tendency, course, or direction.

From M.E. trenden "to roll about, turn, revolve," from O.E. trendan, (cf. O.E. trinde "round lump, ball," O.Fris. trind, M.L.G. trint "round," M.L.G. trent "ring, boundary," Du. trent "circumference," Dan. trind "round").

Ravâl, from row present stem of raftan "to go, walk, proceed" (Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack") + suffix -âl, → -al.

trepidation
  لرزش   
larzeš

Fr.: trépidation   

In medieval astronomy, a spurious oscillatory motion of the equinoxes thought to have a period of 7,000 years. This concept, attributed to Thâbit ibn Qurra (c. 830-901), had a profound influence on medieval astronomy. In order to explain trepidation, Thâbit was said to have added a new sphere to the eight Ptolemaic spheres beyond the sphere of fixed stars.

From L. trepidationem "agitation, trembling," from trepidare "to tremble, hurry," from trepidus "anxious, scared;" cf. Skt. trprá- "hasty;" PIE base *trep- "to shake, tremble."

Larzeš, verbal noun of larzidan "to tremble, shiver;" Mid.Pers. larzidan "to shake, tremble;" Manichean Mid.Pers. rarz- "to shiver with fever;" Proto-Iranian *rarz- "to shake, tremble."

trespass
  ۱) ترارفت؛ ۲) ترارفتن   
1) tarâraft; 2) tarâraftan

Fr.: 1) entrée non autorisée; 2) pénétrer sans autorisation   

1) Law: An unlawful act causing injury to the person, property, or rights of another, committed with force or violence, actual or implied. → light trespass.
2) To commit a transgression or offense; transgress; offend; sin (Dictionary.com).

M.E. trespas, from O.Fr. trespasser "pass beyond or across, cross, traverse; infringe, violate," from tres- "beyond," from L. → trans-, + passer "go by, pass," → pass, → passage.

Tarâraft, tarâraftan, from tarâ-, → trans-, + raft, raftan "to go," → process.

triangle
  سه‌بر، سه‌گوش   
sebar (#), seguš (#)

Fr.: triangle   

The plane figure formed by three lines intersecting in pairs at three points; a three-sided → polygon. → equilateral triangle, → isosceles triangle, → scalene triangle.

M.E., from O.Fr. triangle, from L. triangulum "triangle," from neuter of adj. triangulus "three-cornered," from tri-, → three, + angulus "corner," → angle.

Sebar "three-sided," from , → three, + + bar "side; breadth; breast," variant var (Mid.Pers. var "breast;" Av. vouru "wide, broad, extended" (vourucašāni- "looking far"), related to varah- "breast;" cf. Skt. urú- "wide, broad," úras- "breast;" Gk. eurus "wide, broad;" PIE base uer-, ueru-s"wide, broad").
Seguš "three-cornered," from , → three, + guš "corner, angle," Mid.Pers. gošak "corner."

triangle inequality
  ناهموگی ِ سه‌بری   
nâhamugi-ye sebari

Fr.: inégalité triangulaire   

1) A theorem according to which any side of a triangle is always shorter than the sum of the other two sides.
2) The third requirement for a → distance function describing a → metric space.

triangle; → inequality.

triangulation
  سه‌بربندی   
sebar-bandi (#)

Fr.: triangulation   

In surveying and navigation, the process of deriving the linear distance between any two remote points by the division of a large area into adjacent triangles and using trigonometric relationships.

From M.L. triangulation-, from triangulare "to make triangles," → triangle.

Sebar-bandi, from , → three, + bandi verbal noun from bastan "to form, bind, tie" (Mid.Pers. bastan/vastan "to bind, shut;" Av./O.Pers. band- "to bind, fetter," banda- "band, tie;" cf. Skt. bandh- "to bind, tie, fasten;" Ger. binden; E. bind; PIE base *bhendh- "to bind").

Triangulum
  سه‌بر   
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.

triangle.

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.

trichroism
  سه‌فامی   
sefâmi

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."

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