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: 179
unbiased sample
  نمونان ِ بی‌وَرَک   
nemunân-e a bi-varak

Fr.: échantillon non biaisé   

A sample in which every individual element in the population has an equal chance of being selected.

unbiased; → sample.

unblanketed model
  مدل ِ ناپتومند   
model-e nâpatumand

Fr.: modèle non blanketé   

A stellar atmosphere model which ignores metals and their physical effects. → line-blanketed model; → line blanketing.

un-; → blanketed model.

unbound
  نابندیده   
nâbandidé

Fr.: non lié   

1) Not bound or tied up.
2) Not held by a → chemical bond, → gravity, or other physical force (OxfordDictionaries.com).
See: → unbound charge, → unbound cluster, → unbound system.

un-; → bound.

unbound charge
  بار ِ نابندیده   
bâr-e nâbandidé

Fr.: charge non liée   

Same as → free charge.

unbound; → charge.

unbound cluster
  خوشه‌ی ِ نابندیده   
xuše-ye nâbandidé

Fr.: amas non lié   

A cluster of objects, such as stars or galaxies, in which the members are not tied together gravitationally. In such a cluster the members scatter through space following different directions. → bound cluster.

unbound; → cluster.

unbound system
  راژمان ِ نابندیده   
râžân-e nâbandidé

Fr.: système non lié   

An association of bodies which are not gravitationally tied together.

unbound; → system.

unbound young stellar system (UYSS)
  راژمان ِ ستاره‌ای ِ جوان ِ نابندیده   
râžmân-e setâre-yi-ye javân-e nâbandidé

Fr.: système stellaire jeune non lié   

A class of gravitationally loose stellar conglomerate with a notable apparent shape making it different from typical → bound  → star clusters. The UYSS class includes a large range of objects, which extend at various size scales and at various degrees of self-binding; from small (semi-)compact → unbound systems named → stellar associations, to huge extended superstructures of → massive stars that make up whole parts of Galactic → spiral arms, known as → stellar complexes (Gouliermis, D. A., 2018, PASP 130:072001; arXiv:1806.11541).

unbound; → young; → stellar; → system.

unbounded function
  کریای ِ بیکران   
karyâ-ye bikarân

Fr.: fonction non bornée   

The function y = f(x) in a given range of the argument x if there is no number M such that for all values of x in the range under consideration the inequality | f(x) | ≤ M will be fulfilled. → bounded function.

unbound; → function.

uncertainty
  ناتاشتیگی   
nâtâšigi (#)

Fr.: incertitude   

The state of being uncertain; unpredictability; indeterminacy. → uncertainty principle.

un- + → certainty.

uncertainty principle
  پَروَز ِ ناتاشتیگی   
parvaz-e nâtâštigi

Fr.: principe d'incertitude   

A quantum mechanical principle due to Werner Heisenberg which states that the position and momentum of a particle cannot be determined simultaneously with any arbitrary accuracy. These quantities can be determined only with accuracies limited by the relation Δx.Δp ≥ (1/2)ħ, where Δx is the error in the determination of the position and Δp is the error in the momentum. A similar relation holds for the energy of a particle and the time, ΔE.Δt ≥ (1/2)ħ. Same as → Heisenberg uncertainty principle.

uncertainty; → principle.

unclassified B[e] star (unclB[e])
  ستاره‌یِ B[e]ی ِ بی‌رده   
setâre-ye B[e]-ye bi radé

Fr.: étoile B[e] non-classée   

A temporary designation for a → B[e] star that cannot be placed in any of the four known classes.

classification; → B[e] star.

unclear
  نارونه   
nâruné

Fr.: non clair   

Difficult to see, hear, understand, or to be sure about.

un-; → clear.

unconditional
  نابوتاری، نابوتارمند   
nâbutâri, nâbutârmand

Fr.: inconditionnel   

Not limited by conditions; absolute.

un-; → conditional.

unconscious
  ناهاسن   
nâhâsan

Fr.: non conscient   

Not awake and aware; not responding to one's environment.

non-; → conscious.

unconsciousness
  ناهاسنی   
nâhâsani

Fr.: non conscience   

The → state of being → unconscious.

unconscious; → -ness.

unda
  شن-تل   
šen-tal

Fr.:   

A dune on a planetary surface, used in plural form undae.

From L. unda "wave," cognate with → water.

Šen-tal, from šen "sand" + tal "hill, heap."

under-
  کم-   

Fr.: sous-, faible   

A prefixal use of under, as to indicate place or situation below or beneath. Contrary to → over-.

M.E., from O.E. (cf. O.H.G. untar, Ger. unter, Goth. undar), from PIE *ndhero- "lower;" cf. Av. aδara- (adj.), aδairi- (prep.) "below;" Mid.Pers. êr "below, down; low, under," adar "low," azêr "below, under" (Mod.Pers. zir "below, down"); Skt. ádhara- "lower;" O.E. under "under, among").

Kam- "little, few; deficient, wanting; scarce" (Mid.Pers. kam "little, small, few," O.Pers./Av. kamna- "small, few").

underabundance
  کم‌فراوانی   
kamfarâvâni

Fr.: sous-abondance   

The abundance of a chemical element being lower than a reference value, in particular compared to that of the Sun.

under-; → abundance.

underdamping
  کم‌میرایی   
kam-mirâyi

Fr.: amortissement faible   

The behavior of a damped system when the amount of damping is weak so that the system oscillates with the amplitude gradually decreasing to zero. → overdamping.

under-; → damping.

underestimate
  ۱) کم-بر‌آوردن؛ ۲) کم-بر‌آورد   
1) kam-baravardan; 2) kam-baravard

Fr.: 1) sous-estimer; 2) sous-estimation   

1) To estimate at too low a value, rate, or the like.
2) An estimate that is too low. → overestimate.

under-; → estimate

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