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: 1076
prey animal
  جانور ِ چَواک   
jânevar-e cavâk

Fr.: animal proie   

An animal that is hunted and killed by a → predator as food.

prey; → animal.

Priestley's rings
  حلقه‌های ِ پریستلی   
halqehâ-ye Priestley

Fr.: anneaux de Priestley   

The concentric colored rings formed by an electrical → spark when a → discharge takes place on a metallic plate.

Joseph Priestley (1733-1804), English chemist, author, and clergyman; → ring.

primary
  نخستان   
naxostân

Fr.: primaire, principal   

1) First or highest in rank or importance; chief; principal.
2) Abbreviation for → primary body, → primary star, or → primary mirror.

M.E., from L. primarius "of the first rank, principal," from primus "first."

Naxostân, from naxost, from Mid.Pers. naxust "the first," Parthian Mid.Pers. nxwšt, from naxu, Manichean Parthian nwx "beginning" + -ist superlative suffix, Av. -išta-, cf. Skt. -istha-, Gk. -istos, O.H.G. -isto, -osto, O.E. -st, -est, -ost.

primary body
  جسم ِ نخستان   
jesm-e naxostân

Fr.: corps principal   

The body that is being orbited; such as the → Sun in the → solar system. As regards → multiple star systems, the most massive, or → primary star. See also: → secondary body.

primary; → body.

primary cell
  پیل ِ نخستان   
pil-e noxostân

Fr.:   

A → cell in which the electrochemical action producing the current is not normally reversible. Such a cell cannot be recharged by an electric current. → secondary cell.

primary; → cell.

primary cosmic rays
  پرتوهای ِ کیهانی ِ نخستان   
partowhâ-ye keyhâni-ye naxostân

Fr.: rayons cosmiques primaires   

The → cosmic rays which arrive on the Earth's → atmosphere from the outer space. The primary cosmic rays are very high energy → protons and to a lesser extent heavier nuclei which rain upon the Earth from all diretions in the outer space. They contain about 90% protons, 7% → alpha particles and about 1% still heavier nuclei of amost all the atoms from Li to Ni ( → mass number< 60). See also: → secondary cosmic rays.

primary; → cosmic; → ray.

primary eclipse
  گرفت ِ نخستان   
gereft-e noxostân

Fr.: éclipse primaire   

Of a transiting → exoplanet, the event and the interval of time during which the planet passes in front of its host star. The planet occults a portion of the stellar disk, and a fraction of light from the star is seen after traversal through the atmosphere around the planet's limb. → secondary eclipse.

primary; → eclipse.

primary mirror
  آینه‌ی ِ نخستان   
âyene-ye noxostân

Fr.: miroir primaire   

In a → reflecting telescope, the first mirror that collects the light and focuses it to the → focal plane.

primary; → mirror.

primary rainbow
  رنگین‌کمان ِ نخستان   
rangin-kamân-e naxostân

Fr.: arc-en-ciel primaire   

The main rainbow that forms between about 40° and 42° from the → antisolar point (or about 50° from the → antisolar point), as viewed by the observer. The light path involves → refraction and a → single  → reflection inside the water → droplet. If the drops are large, 1 millimeter or more in diameter, red, green, and violet are bright but there is little blue.

As the droplets get smaller, red weakens.

Rainbows are not seen in midday since the whole 42° circle is below the horizon at most latitudes. So rainbows tend to be seen most in the later afternoon when a thundershower has passed and the Sun is illuminating from the west.

primary; → rainbow.

primary star
  ستاره‌ی ِ نخستان   
setâre-ye naxostân

Fr.: étoile principale   

In a → multiple star system, the most massive → component. In other words, the star nearest to the system's → center of garvity.

primary; → star .

prime
  نخست، نخستین، نخستی   
naxost, naxostin, naxosti

Fr.: premier   

1) Of the first importance; of the highest rank.
2) Same as → prime number.

M.E., from L. primarius "of the first rank, principal," from primus "first."

Naxost, naxostin, naxosti, from Mid.Pers. naxust "the first," Parthian Mid.Pers. nxwšt, from naxu, Manichean Parthian nwx "beginning" + -ist superlative suffix, Av. -išta-, cf. Skt. -istha-, Gk. -istos, O.H.G. -isto, -osto, O.E. -st, -est, -ost.

prime focus
  کانون ِ نخستی   
kânun-e naxosti

Fr.: foyer primaire   

The focal point of a large primary reflecting mirror. This focus actually falls at a point just within the upper structure of the telescope and provides a large field of view.

primary; → focus.

prime meridian
  نیمروزان ِ نخستی   
nimruzân-e noxosti

Fr.: méridien origine   

The meridian at which longitude is defined to be 0°. The meridian running through Greenwich.

primary; → meridian.

prime number
  عدد ِ نخست   
'adad-e naxost

Fr.: nombre premier   

A number which is divisible by no whole number other than itself and one.

prime; → number.

prime vertical
  هجین ِ نخستی   
hajin-e noxosti

Fr.: premier vertical   

The great circle through the observer's zenith that intersects the horizon at the west and east points. → vertical circle.

primary; → vertical.

primeval atom
  اتم ِ نخستین   
atom-e naxostin

Fr.: atome primitif   

Lemaître's (1931) name for the early dense Universe, which later became known as the → Big Bang theory.

From L. primaevus "early in life," from primus "first," → prime, + aevum "an age," + → -al; → atom.

primordial
  بن‌آغازین   
bonâqâzin

Fr.: primordial   

Pertaining to or existing at or from the very beginning.

From L.L. primordialis "first of all, original," from L. primordium "the beginning," from primus "first" + stem of ordiri "to begin."

Bonâqâzin, from bon "basis; root; foundation; bottom" (Mid.Pers. bun "root; foundation; beginning," Av. būna- "base, depth," cf. Skt. bundha-, budhná- "base, bottom," Pali bunda- "root of tree") + âqâzin "pertaining to the beginning," from âqâz "beginning" (Proto-Iranian *āgāza-, from prefix ā- + *gāz- "to take, receive," cf. Sogdian āγāz "beginning, start," pcγz "reception, taking").

primordial abundance
  فراوانی ِ بن‌آغازین   
farâvâni-ye bonâqâzin

Fr.: abondance primordiale   

The relative amount of a light element (e.g. deuterium, lithium, helium) synthesized in the early Universe.

primordial; → abundance.

primordial black hole
  سیه‌چال ِ بن‌آغازین   
siyahcâl-e bonâqâzin

Fr.: trou noir primordial   

A black hole formed following the Big Bang event due to incredibly violent turbulence that squeezed concentrations of matter to high densities. These black holes, first suggested by Stephen Hawking, are expected to have a mass comparable to that of a mountain and a size as small as an atom. Same as → mini black hole.

primordial; → black hole.

primordial curvature perturbation
  پرتورش ِ خمیدگی ِ بن‌آغازین   
partureš-e xamidegi-ye bonâqâzin

Fr.: perturbation de courbure primordiale   

In cosmological models, the phenomenon that is supposed to seed the → cosmic microwave background anisotropies and the structure formation of the Universe.

primordial; → curvature; → perturbation.

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