An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 30 Search : element
alpha element
  بن‌پار ِ آلفا   
bonpâr-e âlfâ

Fr.: élément α   

A → chemical element synthesized in → massive stars by → alpha particle capture leading to iron before the advent of a → type II supernova. Stable alpha elements are: C, O, Ne, Mg, Si, S, Ar, Ca.

alpha; → element.

alpha element knee
  زانوی ِ بن‌پار ِ آلفا   
zânu-ye bonpâr-e âlfâ


The point in the plot showing → alpha element abundances ([α/Fe]) of a galaxy as a function of the → metallicity ([Fe/H]) where the α-element abundance drops. The metallicity of the turn-over in α-element abundances is linked to the → star formation rate during the early stage of star formation in a galaxy and therefore also depends on the total mass of the system. Higher star formation efficiency leads to higher overall metallicity before the onset of → Type Ia supernova → enrichment, and thus to a knee that is located at higher [Fe/H] values.

alpha; → element; → knee.

atmophile element
  بن‌پار ِ اتمودوست، ~ هوادوست، ~ گازدوست   
bonpâr-e atmodust, ~ havâdust, ~ goazdust

Fr.: élément atmophile   

In the → Goldschmidt classification, a → chemical element that is extremely → volatile, i.e., forms a gas or liquid at the surface of the Earth. The atmophile elements are usually concentrated in the terrestrial → atmosphere and → hydrosphere. They are → hydrogen (H), → carbon (C), → nitrogen (N), and → noble gas/qot>es, namely → helium (He), → neion (Ne), → argon (Ar), → krypton (Kr), → xenon (Xe), and → radon (Rn) (Pinti D.L., 2017, Atmophile Elements. In: White W. (eds) Encyclopedia of Geochemistry, Springer).

atmophile; → element.

chalcophile element
  بن‌پار ِ خالکودوست، ~ مسدوست   
bonpâr-e xâlkdust, ~ mesdust

Fr.: élément chalcophile   

In the → Goldschmidt classification, a → chemical element that has an → affinity for sulphur, and therefore tending to be more abundant in sulphide minerals and ores than in other types of rock. This group is depleted in the silicate Earth and may be concentrated in the core. The group includes → silver (Ag), → arsenic (As), → bismuth (Bi), → cadmium (Cd), → copper (Cu), → mercury (Hg), → indium (In), → lead (Pb), → sulfur (S), → antimony (Sb), → selenium (Se), → tellurium (Te), and → thallium (Tl). As a consequence of their relatively low condensation temperatures (500-1100 K), most of these elements are depleted in terrestrial planets with respect to chondrites.

chalcophile; → element.

chemical element
  بن‌پار ِ شیمیایی، عنصر ِ ~   
bonpâr-e šimiyâyi (#), onsor-e ~ (#)

Fr.: élément chimique   

A substance which consists entirely of atoms of the same → atomic number and cannot be decomposed or changed into another substance using chemical means. Currently 118 chemical elements are known, the most abundant being → hydrogen. → periodic table.

chemical; → element.

density of an element
  چگالی ِ بن‌پار   
cagâli-ye bonpâr

Fr.: densité d'élément   

The number of units of mass of the → chemical element that are present in a certain volume of a medium. The density of an element depends on temperature and pressure. The element Osmium has the highest known density: 22.61 g/cc; in comparison gold is 19.32 g/cc and lead 11.35 g/cc.

density; → element.

  بن‌پار، عنصر   
bonpâr (#), onsor (#)

Fr.: élément   

1) General: A component or constituent of a whole or one of the parts into which a whole may be resolved by analysis.
2) Astro.: Any of the data required to define the precise nature of an orbit and to determine the position of a planet in the orbit at any given time. → orbital element.
3) Chemistry:: One of the 117 presently known substances that cannot be decomposed by chemical reaction into a simpler substance.
4) Math.:a) Of a cylinder or cone, the generating line of the surface, taken in any position. b) Of a set, any member of the set.

From O.Fr. élément, from L. elementum "rudiment, one of the four elements, first principle," origin unknown.

Bonpâr, 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" + pâr contraction of 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 assign;" 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." Onsor from Ar.

element diffusion
  پخش ِ بن‌پار   
paxš-e bonpâr

Fr.: diffusion des éléments   

An important physical process occurring in stars, which is the relative separation of the various → chemical elements. It is caused by → gravitational settling and → thermal diffusion, on the one hand, and → radiative levitation on the other. This process, which was described by Michaud (1970) to account for the abundance anomalies observed in → chemically peculiar  → A star, is now recognized as occuring in all types of stars. Its influence on the observed → chemical abundances is extremely variable, however, due to competing macroscopic motions like → convective  → mixing or rotation-induced → turbulence. In the Sun, no observable abundance anomalies are expected from element diffusion, as the time scale of the process is longer than the solar lifetime. However the small induced → depletion of → helium and → heavy elements by about 20% is detectable through → helioseismology. Such detections are more difficult in stars, as only global → oscillation modes can be detected, in contrast to the Sun, where local oscillations of the surface can be analyzed (Théado et al., 2005, A&A 437, 553).

element; → diffusion.

elemental abundance
  فراوانی ِ بن‌پار، ~ عنصر   
farâvâni-ye bonpâr, ~ onsor

Fr.: abondance élémentaire, ~ d'un élément   

Emission nebulae: The relative amount of a given → chemical element in an ionized nebula with respect to another element, usually → hydrogen. Elemental abundance ratios of → emission nebulae are obtained either by adding the observed → ionic abundances of the element or by using → ionization correction factors. Same as → total abundance.

Elemental, from M.L. elementalis, → element + -al; abundance, from O.Fr. abundance, from L. abundantia "fullness," from abundare "to overflow," from L. ab- "away" + undare "to surge," from unda "water, wave;" → abundance.

elementary particle
  ذره‌ی ِ بنیادین   
zarre-ye bonyâdin (#)

Fr.: particule élémentaire   

A particle which cannot be divided into other constituents. More specifically, a particle whose field appears in the fundamental field equations of the unified field theory of elementary particles, in particular in the Lagrangian. For example, the → electron, the → photon, and the → quark are elementary particles, whereas the proton and neutron are not. The elementary nature of a particle can be revised depending on new observations or theories. Also called → fundamental particle.

Elementary, M.E. elementare, from M.F. élémentaire, from L. elementarius, from → element + adj. suffix -arius; → particle.

Bonyâdin, from bonyâd "basis, foundation," variant of bonlâd, from bon "basis; root; foundation; bottom" → element + lâd "root; foundation; reason, cause; wall" + adj. suffix -in.

elementary time
  زمان ِ بنیادین   
zamân-e bonyâdin

Fr.: temps élémentaire   

The time required for → light to cross the classical radius of the electron (→ electron radius): te = re/c ≅ 10-23 s.

elementary particle; → time.

elements of the orbit
  بن‌پارهای ِ مدار، عنصرهای ~   
bonpârhâ-ye madâr, onsorhâ-ye ~ (#)

Fr.: éléments orbitaux   

orbital element.

element; → orbit.

heavy element
  بن‌پار ِ سنگین   
bonpâr-e sangin (#)

Fr.: élément lourd   

In astrophysics, any → chemical element heavier than → helium. Such elements are also inappropriately referred to as "→ metals."

heavy; → element.

highly siderophile element (HSE)
  بن‌پار ِ بسیار آهندوست   
bonpâr-e besyâr âhandust

Fr.: élément hautement sidérophile   

A → chemical element that is → geochemically characterized as having a strong → affinity to partition into → metals relative to → silicates. The highly siderophile elements, → ruthenium (Ru), → rhodium (Rh), → palladium (Pd), → rhenium (Re), → osmium (Os), → iridium (Ir), → platinum (Pt), and → gold (Au), are of interest to planetary scientists because they give insights into the early history of → accretion and → differentiation. HSEs prefer to reside in the metal of planetary cores. Therefore, the HSEs found in planetary → mantles are considered to be overabundant relative to their known preferences for metal over silicate. Therefore, it has been inferred that processes other than → equilibrium partitioning have been responsible for establishing the abundances of → mantle siderophiles. A detailed understanding of the absolute → concentrations and relative abundances of the HSEs may therefore give important insights into the earliest history of a planet (Jones et al., 2003, Chemical Geology 196, 21).

From Gk. sidero-, from sideros "iron" + → -phile.

Âhandust, from âhan, → iron, + -dust, → -phile.

identity element
  بن‌پار ِ ایدانی   
bonpâr-e idâni

Fr.: élément neutre   

In a mathematical system, an element which leaves unchanged any other element on which it operates. Thus 0 is the identity element for addition: a + 0 = a. And 1 is the identity element for multiplication: a . 1 = a.

identity; → element.

iron peak element
  بن‌پار ِ ستیغ ِ آهن   
bonpâr-e setiq-e âhan

Fr.: élémént du pic du fer   

A member of a group of elements with → atomic masses A about 40 to 60 that are synthesized by the → silicon burning process and appear in the → iron peak. They are mainly: → titanium (Ti), → chromium (Cr), → manganese (Mn), → iron (Fe), → cobalt (Co), and → nickel (Ni).

iron; → peak; → element.

light element
  بن‌پار ِ سبک   
bonpâr-e sabok (#)

Fr.: élément léger   

In astrophysics, a chemical element that has an atomic number of one, two, or three, such as hydrogen, helium, and lithium; sometimes also beryllium and boron.

light; → element.

lithophile element
  بن‌پار ِ سنگدوست، ~ لیتودوست   
bonpâr-e sangdust, ~ litodust

Fr.: élément lithophile   

In the → Goldschmidt classification, a → chemical element that shows an → affinity for → silicate phases and is concentrated in the silicate portion of the Earth (→ crust and → mantle). This group includes → lithium (Li), → beryllium (Be), → sodium (Na), → magnesium (Mg), → potassium (K), → calcium (Ca), → barium (Ba), → titanium (Ti), → chromium (Cr), → aluminium (Al), → silicon (Si), → phosphorus (P), → chlorine (Cl), etc.

lithophile; → element.

mean element
  بن‌پار ِ میانگین   
bonpâr-e miyângin

Fr.: élément moyen   

An element of an adopted reference orbit that approximates the actual, perturbed orbit. Mean elements may serve as the basis for calculating perturbations.

mean; → element.

neutron-capture element
  بن‌پار ِ گیر‌افت ِ نوترون   
bonpâr-e giroft-e notron

Fr.: élément de capture de neutron   

A → nucleosynthesis process responsible for the generation of the → chemical elements heavier than the → iron peak elements. There are two possibilities for → neutron capture: the slow neutron-capture process (the → s-process) and the rapid neutron-capture process (the → r-process). The s-process is further divided into two categories: the weak s-component and the main s-component. Massive stars are sites of the weak component of s-process nucleosynthesis, which is mainly responsible for the production of lighter neutron-capture elements (e.g. Sr, Y, and Zr). The s-process contribution to heavier neutron-capture elements (heavier than Ba) is due only to the main s-component. The low- to intermediate-mass stars (about 1.3-8 Msun) in the → asymptotic giant branch (AGB) are usually considered to be sites in which the main s-process occur. There is abundant evidence suggesting that → Type II supernova (SNe II) are sites for the synthesis of the r-process nuclei, although this has not yet been fully confirmed. The observations and analysis on → very metal-poor stars imply that the stars with [Fe/H] ≤ -2.5 might form from gas clouds polluted by a few supernovae (SNe). Therefore, the abundances of → heavy elements in → metal-poor stars have been used to learn about the nature of the nucleosynthetic processes in the early Galaxy (See, e.g., H. Li et al., 2013, arXiv:1301.6097).

neutron;→ capture; → element.

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