An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 30 Search : element
orbital element
  بُن‌پارِ مداری   
bonpâr-e madâri

Fr.: élément orbital   

Any of the six parameters needed to specify the → orbit of an object around a → primary body (such as a planet around the Sun or a satellite around the Earth) and give its position at any instant. Two of them define the size and the form of the orbit: → semi-major axis (a) and → eccentricity (e). Three angular values determine the orbit position in space: the → inclination (i) of the object's → orbital plane to the reference plane (such as the → ecliptic), the → longitude of ascending node (Ω), and the → argument of periapsis (ω). And finally the sixth element is the → time of periapsis passage which allows calculating the body's position along the orbit at any instant.

orbital; → element.

osculating elements
  بن‌پارهایِ آبوسشی   
bonpârhâ-ye âbuseš

Fr.: éléments orbitaux osculateurs   

The orbital elements of an osculating orbit.

osculating; → element.

parent element
  بن‌پار ِ پرمار   
bonpâr-e permâr

Fr.: élément parent   

A radioactive element that spontaneously decays into a new substance. The product of this decay is known as a "daughter" element.

parent; → element.

platinum group element (PGE)
  بن‌پار ِ گروه ِ پلاتین   
bonpâr-e goruh-e pelâtin

Fr.: élément du groupe du platine   

One of the six metals → platinum (Pt), → iridium (Ir), → osmium (Os), → palladium (Pd), → rhenium (Rh), and → ruthenium (Ru) that are grouped together in the → periodic table. They are relatively hard and resistant to corrosion and are used in jewellery and in some industrial applications. All are resistant to chemical attack.

platinum; → group; → element.

radioelement
  پرتو-بن‌پار   
partow bonpâr

Fr.: radioélément   

An element, such as uranium, whose isotopes are all radioactive.

radio; → element.

rare earth element
  بن‌پار ِ خاکی ِ کمیاب، خاک ِ کمیاب   
bonpâr-e xâki-ye kamyâb, xâk-e kamyâb

Fr.: terre rare   

Any of the group of metallic → chemical elements with → atomic numbers between 57 and 71 inclusive. The name is an inappropriate terminology, since they are neither rare nor earth; preferred name → lanthanide.

rare; → earth; → element.

siderophile element
  بن‌پار ِ آهندوست   
bonpâr-e âhandust

Fr.: élément sidérophile   

In the → Goldschmidt classification, any → chemical element that has an → affinity to combine with → iron rather than some other element. These elements are concentrated in the → Earth's core. The group includes → iron (Fe), → nickle (Ni), → cobalt (Co), → platinum (Pt), → gold (Au), → tin (Zn), and → tantalum (Ta). The siderophile elements include → highly siderophile element (HSE).

siderophile; → element.

trace element
  بن‌پار ِ مله   
bonpâr-e malé

Fr.: élément trace, oligo-élément   

Any → chemical element that is found in extremely small amounts, especially one used by organisms and held essential to maintain proper physical functioning.

trace; → element.

transuranium element
  بن‌پار ِ ترا-اورانیومی   
bonpâr-e tarâ-urâniomi

Fr.: élément transuranien   

An element beyond uranium in the periodic table, with atomic number greater than 92. Such elements do not occur in nature, but may be obtained by suitable nuclear reactions. They are all radioactive and members of the actinide group.

trans-; → uranium; → element.

volatile element
  بن‌پار ِ پرا   
bonpâr-e parrâ

Fr.: élément volatile   

In → planetary science, any of a group of → chemical elements and → chemical compounds with relatively low → boiling points that are associated with a planet's or moon's → crust and/or → atmosphere. For example, H, He, C, N, O are underabundant (relative to the solar → photospheric values) in all types of → meteorites, including the C1 → carbonaceous chondrites. Any heating of the meteorite parent body subsequent to its formation would tend to drive the volatile elements out of the rock, whence it sublimated into → interplanetary medium.

volatile; → element.

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