An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < abs ann con deg exc gen hie int mic ove reg tem > >>

Number of Results: 232 Search : era
microlensing degeneracy
  واگنی ِ ریز‌لنزش   
vâgeni-ye riz-lenzeš

Fr.: dégénérescence des paramètres de l'effet de microlentille   

Determining the three various parameters of a microlensing event (the lens-source relative parallax and proper motion, and the mass of the lens) from only one physical parameter (the event time scale). Currently the microlensing degeneracy affects the vast majority of events and makes any individual event impossible to interpret with certainty.

microlensing; → degeneracy.

kâni (#)

Fr.: minéral   

A naturally occurring inorganic solid. The internal crystalline structure of a mineral is controlled by its elemental composition.

From M.L. minerale "something mined," from neuter of mineralis "pertaining to mines," from minera "mine."

Kâni "mineral," from kân "mine," from kandan "to dig" (Mid.Pers. kandan "to dig;" O.Pers. kan- "to dig," akaniya- "it was dug;" Av. kan- "to dig," uskən- "to dig out" (→ ex- for prefix us-); cf. Skt. khan- "to dig," khanati "he digs").

neutron degeneracy
  واگنی ِ نوترون   
vâgeni-ye notron

Fr.: dégénérescence des neutrons   

The state of degeneracy created when the density of matter is so high that neutrons cannot be packed any more closely together. This condition occurs in the core of stars above 1.44 solar masses (→ Chandrasekhar limit) where under the gravitational collapse electrons and protons are forced to combine into neutrons. Therefore, in a → neutron star all the lowest neutron energy levels are filled and the neutrons are forced into higher and higher energy levels, since according to Pauli Exclusion Principle no two neutrons (fermions) can occupy identical states. This creates an effective pressure which prevents further gravitational collapse. However, for masses greater than 3 solar masses, even neutron degeneracy cannot prevent further collapse and it continues toward the black hole state.

neutron; → degeneracy.

New General Catalogue (NGC)
  کاتالوگ ِ هروین ِ نو   
kâtâlog-e harvin-e now

Fr.: New General Catalogue   

A catalogue of 7,840 non-stellar objects compiled by J. L. E. Dreyer and published in 1888. A further 1,529 objects were listed in a supplement that appeared seven years later, called the → Index Catalogue (IC). The Second Index Catalogue of 1908 extended the supplementary list to 5,386 objects.

new; → general; → catalog

Noachian era
  دوران ِ نوحیانه   
dowrân-e Nuhiyâné

Fr.: ère noachienne   

>Noachian era = dowrân-e Nuhiyâné     دوران ِ نوحیانه

Fr.: ère noachienne

The oldest geological era on Mars, which started from the planet's birth and lasted until about 3.8 billion years ago. Features such as dried-up river valleys and delta features suggest that the climate may have been warmer and wetter. It is believed also that lakes and oceans could have existed. → Amazonian era; → Hesperian era.

The oldest geological era on Mars, which started from the planet's birth and lasted until about 3.8 billion years ago. Features such as dried-up river valleys and delta features suggest that the climate may have been warmer and wetter. It is believed also that lakes and oceans could have existed. → Amazonian era; → Hesperian era.

Noachian, named for → Noachis Terra "Land of Noah;" → era.

noise temperature
  دمای ِ نوفه   
damâ-ye nufé

Fr.: température de bruit   

A means for specifying the noise generated as unwanted → electromagnetic radiation in a receiver system or one of its components. It is usually measured in terms of the equivalent temperature in a → Rayleigh-Jeans spectrum. Noise temperature is used mainly in radio astronomy.

noise; → temperature.

non-hierarchical multiple system
  راژمان ِ بستایی ِ ناپایگانی   
râžmân-e bastâyi-ye nâpâygâni

Fr.: système multiple non hiérarchique   

A → multiple star system that lacks the characteristics of a → hierarchical multiple system.

non-; → hierarchical; → multiple; → system.

nucleosynthetic era
  دوران ِ هسته‌هندایش   
dowrân-e haste-handâyi

Fr.: ère nucléosynthétique   

The era following the leptonic era, between 1 second and 1000 seconds after the Big Bang, when neutrons were abundant and helium and deuterium were synthesized.

nucleosynthetic; → era.

  ۱) شمارال؛ ۲) شماره‌ای، عددی   
1) šomârâl; 2) šomâre-yi (#), adadi (#)

Fr.: 1) numéral; 2) numéral, numérique   

1) A symbol, group of symbols, or word used to express a number. For any number there is an infinite number of numeral expressions. For example, the number two can be written as 2, II, binary 10, 4/2, 18/8, etc.
2) Of, pertaining to, or consisting of numbers or numerals.

From L.L. numeralis "of, or belonging to number," → number + → -al

Šomârâl, from šomâr, → number, + -al, → -al.

numeral system
  راژمان ِ عددی، ~ عددها   
râžmân-e adadi, é adadhâ

Fr.: système de numération   

A set of → symbols and → rules for representing → numbers. Same as → number system. See also: → Greek numeral system, → Roman numeral system, → Indian numeral system.

numeral; → system.

šomârân (#)

Fr.: numérateur   

The quantity x in a fraction x/y). The quantity y is the → denominator.

L.L. numerator "a counter, numberer," from L. numera(re) "to number," → number + -tor a suffix forming personal agent nouns from verbs and, less commonly, from nouns.

Šomârân, agent noun of šomârdan, → number.

  آپاریدنیگی، آپارش‌پذیری   
âpâridanigi, âpârešpaziri

Fr.: opérabilité   

The capability of being put into use, operation, or practice.

operable; → -ity.

  آپاریدنی، آپارش‌پذیر   
âpâridani, âpârešpazir

Fr.: opérable   

Capable of operating or of being operated.

operate; → -able.


Fr.: opérer   

To function or work; to make something function or work.

From L. operari "to work, labor," L. opus "a work, labor, exertion," Av. *āpah-, *apah- "to do, operate," see below, Skt. ápas- "work, action, religious act;" O.H.G. uoben "to start work, to practice, to honor;" Ger. üben "to exercise, practice;" Du. oefenen; O.E. æfnan "to perform, work, do," afol "power"); PIE base *op- "to work, perform."

Âpâridan, from âpâr-, from Av. *āp(ah)- "to do, operate," as above, + suffix -ar (as in vadar- "weapon," zafar- "jaw," baēvar- "thousand," and so on), shifted to -âr, + -idan suffix of infinitives. The Av. *āpah- "to do, operate," is extant in Mod.Pers. xub "good;" Mid.Pers. hwp, xub "good;" from Av. huuāpah- "doing good work, masterly," from huu-, hv- "good" → eu- + āpah- "work, deed," hauuapanha- "creativity;" cf. Skt. sv-ápas- "doing good work, skillful;" PIE base *op-, as above.

operating system (OS)
  راژمان ِ آپارش   
râžmân-e âpâreš

Fr.: système d'exploitation   

The program that, after being initially loaded into the → computer by a boot program, → manages all the other → programs in a computer.

operating; → system.


Fr.: opération   

1) General: An act or instance, process, or manner of functioning or operating.
2a) Math.: A mathematical process, as addition, multiplication, or differentiation.
2b) The action of applying a mathematical process to a quantity or quantities.
3) Computers: An action resulting from a single instruction.

Verbal noun of → operate


Fr.: opérationnel   

Pertaining to a process or series of actions for achieving a result.

Adj. of → operation.

operational calculus
  افماریکِ آپارشی   
afmârik-e âpâreši

Fr.: calcul opérationnel   

A method of mathematical analysis which in many cases makes it possible to reduce the study of differential operators, pseudo-differential operators and certain types of integral operators, and the solution of equations containing them, to an examination of simpler algebraic problems. It is also known as operational analysis.

operational; → calculus.


Fr.: opérationalisme   

In the philosophy of science, the view that → concepts are defined in terms of measuring operations which determine their applicability. Same as operationism.

operation; → -ism.


Fr.: opérateur   

Math.: Something that acts on another function to produce another function. In linear algebra an "operator" is a linear operator. In calculus an "operator" may be a differential operator, to perform ordinary differentiation, or an integral operator, to perform ordinary integration.

From → operate; + → -or.

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