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: 72 Search : one
opponent
  پادیستگر   
pâdistgar

Fr.: opposant, adversaire   

A person who is on an opposing side in a game, contest, controversy, or the like; adversary (Dictionary.com).

L. opponent-, p.p. of opponere "to oppose, to object to," literally "set against, set opposite," from op- variant of ob- before p "against" + ponere "to put, set, place," → position.

Pâdistgar, from pâdist, → opposition, + -gar, → -or.

optical component
  همنه‌ی ِ نوریک   
hamne-ye nurik

Fr.: composante optique   

Any device such as a → lens, → prism, → mirror, and/or other similar objects used in an → optical system.

optical; → component.

overtone
  اَبَرتن   
abarton (#)

Fr.: harmonique   

A note of lesser intensity and higher frequency than the fundamental note, and superimposed upon the latter to give a note of characteristic quality. Overtones whose frequencies are an integral multiple of the fundamental are said to form a harmonic series. The fundamental with a frequency f1 is the first harmonic. The frequency 2f1 is the first overtone and so on.

over-; → tone.

ozone
  ازون   
ozon (#)

Fr.: ozone   

A form of oxygen, O3, in which the molecule is made of three atoms instead of the usual two.

From Ger. Ozon, coined in 1840 by Ger. chemist Christian Friedrich Schönbein (1799-1868) from Gk. ozon, neute pr.p. of ozein "to smell." So called for its peculiar odor.

ozone hole
  سوراخِ اُزون   
surâx-e ozon (#)

Fr.: trou d'ozone   

Not really a "hole," but a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August-October). It was first noticed in the 1970s by a research group from the British Antarctic Survey.

ozone; → hole.

ozone layer
  لایه‌یِ اُزون   
lâye-ye ozon (#)

Fr.: couche d'ozone   

An atmospheric layer that contains a high proportion of oxygen that exists as ozone. It acts as a filtering mechanism against incoming ultraviolet radiation. It is located between the troposphere and the stratosphere, around 15 to 20 kilometers above the Earth's surface.

ozone; → layer.

ozone shield
  سپرِ اُزون   
separ-e ozon (#)

Fr.: bouclier d'ozone   

The ozone layer within the stratosphere that filters out potentially lethal intensities of ultraviolet radiation from the Sun.

ozone; shield, from O.E. scield, scild, related to sciell "seashell, eggshell," from P.Gmc. *skeldus (cf. Du. schild, Ger. Schild, Goth. skildus); PIE base *(s)kel- "to cut."

Separ "shield," from Mid.Pers. spar "shield;" cf. Skt. phalaka- "board, lath, leaf, shield," phálati "(he) splits;" Gk. aspalon "skin, hide," spolas "flayed skin," sphalassein "to cleave, to disrupt;" O.H.G. spaltan "to split;" Goth. spilda "board;" PIE base *(s)p(h)el- "to split, to break off;" → ozone.

partial ionization zone
  زنار ِ یونش ِ پاری   
zonâr-e yoneš-e pâri

Fr.: zone d'ionisation partielle   

One of several zones of the stellar interior where increased → opacity can provide the → kappa mechanism to drive → pulsations. See also → Kramers' law. In these zones where the gases are partially ionized, part of the energy released during a layer's compression can be used for further ionization, rather than raising the temperature of the gas. Partial ionization zones modulate the flow of energy through the layers of the star and are the direct cause of → stellar pulsation. The partial ionization zones were first identified by the Russian astronomer Sergei A. Zhevakin (1916-2001) in the 1950s. In most stars there are two main ionization zones. The hydrogen partial ionization zone where both the ionization of neutral hydrogen (H ↔ H+ + e-) and the first ionization of helium (He ↔ He+ + e-) occurs in layers with a characteristic temperature of 1.5 x 104 K. The second, deeper zone is called the He+ partial ionization zone, and involves the second ionization of helium (He+↔ He++ + e-), which occurs deeper at a characteristic temperature of 4 x 104 K. The location of these ionization zones within the star determines its pulsational properties. In fact if the → effective temperature of the star is ≥ 7500 K, the pulsation is not active, because the ionization zones will be located very near to the surface. In this region the density is quite low and there is not enough mass available to drive the oscillations. This explains the blue (hot) edge of the instability strip on the → H-R diagram. Otherwise if a star's surface temperature is too low, ≤ 5500 K, the onset of efficient convection in its outer layers may dampen the oscillations. The red (cool) edge of the instability strip is believed to be the result of the damping effect of convection. He+ ionization is the driving agent in → Cepheids. See also → gamma mechanism.

partial; → ionization; → zone.

passive component
  همنه‌ی ِ اکار   
hamne-y akâr

Fr.: composante passive   

An electronic component which contains no source of power, in contrast to active components.

passive; → component.

phone
  آوا   
âvâ (#)

Fr.: son   

A speech sound considered as a physical event without regard to its place in the sound system of a language.

From Gk. phone "voice, sound," phonein "to speak;" cf. L. fama "talk, reputation, fame."

Âva "voice, sound," related to âvâz "voice, sound, song" (both prefixed forms), bâng "voice, sound, clamour" (Mid.Pers. vâng), vâžé "word," variants vâj-, vâk-, vâ-, vâz-, vât-; Av. vacah- "word," vaocanghê "to decalre" (by means of speech), from vac- "to speak, say;" cf. Skt. vakti "speaks, says," vacas- "word;" Gk. epos "word;" L. vox "voice;" PIE base *wek- "to speak."

phoneme
  واج   
vâj (#)

Fr.: phonème   

The smallest phonetic unit in a language that can distinguish one word from another.

From Fr. phonème, from Gk. phonema "speech sound, utterance," from phonein "to sound," → phone.

Vâj "voice," variant of vâž, vâz-, âvâz etc., → phone.

phonetics
  آواییک   
âvâyik (#)

Fr.: phonétique   

A branch of linguistics dealing with the analysis, description, and classification of speech sounds. More specifically, phonetics deals with the physical production of → phonemes regardless of language, while → phonology studies how those sounds are put together to create meaningful words in a particular language.

From phonetic, from N.L. phoneticus, from Gk. phonetikos "vocal," from phonet(os) "utterable," verbal adj. of phonein "to speak clearly, utter," from → phone + -ikos, → -ics.

&ACIRC;vâyik, from âvâ, → phone, + -ik, → -ics.

Pleione
  پلیونه   
Pleyoné (#)

Fr.: Pléioné   

A star in the constellation → Taurus and a member of the → Pleiades star cluster. Pleione is a blue-white B-type → main sequence → dwarf with a mean apparent magnitude of +5.09. It is a variable star and its brightness varies from magnitude +4.77 to +5.50. It is approximately 380 light-years from Earth.

Pleione was an Oceanid nymph. She lived in a southern region of Greece called Arcadia, on a mountain named Mount Kyllini. She married Atlas and gave birth to the Hyades, Hyas and the Pleiades.

postpone
  پس‌افکندن   
pas afkandan (#)

Fr.: renvoyer, remettre, ajouner   

To put off to a later time; defer.

From L. postponere "put after; neglect; postpone," from → post- "after" + ponere "to put, place," → position.

Pas afkandan, literally "to throw after," "to postpone" (Dehxodâ), from pas- "after," → post-, + afkandan "to throw," → stopword.

practitioner
  ورزمند   
varzmand

Fr.: praticien   

A professional man, especially in medicine and the law.

Alteration of practician, → practice (+ -ian) + -er, → -or.

Varzmand, from varz, → practice, + -mand, → -ist.

protoneutron star
  ستاره‌ی ِ پوروا-نوترونی   
setâre-ye purvâ-notroni

Fr.: proto-étoile à neutrons   

A compact, hot, and → neutrino-rich object that results from a → supernova explosion and is a transition between an → iron core and a → neutron star or → black hole. The life span of a protoneutron star is less than one minute.

proto-; → neutron; → star.

radiative zone
  زنار ِ تابشی   
zonâr-e tâbeši

Fr.: zone radiative   

The region of a star in which the energy generated by → nuclear fusion in the core is transferred outward by → electromagnetic radiation and not by → convection. Such zones occur in the interior of low-mass stars, like the Sun, and the envelopes of → massive star. The radiative zone of the Sun starts at the edge of the core of the Sun, about 0.2 solar radii, and extends up to about 0.7 radii, just below the → convective zone.

radiative; → zone.

sandstone
  ماسه‌سنگ   
mâse-sang (#)

Fr.: grès   

Variously colored → sedimentary rock composed mainly of sand-like quartz grains cemented by calcite, clay, or iron oxide. The sand accumulated originally underwater in shallow seas or lakes, or on the ground along shorelines or in desert regions.

sand; → stone.

shadow cone
  مخروط سایه   
maxrut-e sâyé

Fr.: cône d'ombre   

A cone-shaped shadow cast by Earth or the Moon pointing away from the Sun. The dark inner portion of the shadow cone is called the → umbra. The lighter outer portion of the shadow is called the → penumbra. Its extension is called the → antumbra.

shadow; → cone.

shinbone
  درشت-نی   
dorošt-ney

Fr.: tibia   

tibia.

tibia

Doroštney, literally "big reed," from dorošt, → macro-, + ney "reed, cane."

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