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: 88 Search : stellar
substellar
  زیر-ستاره‌ای   
zir-setâre-yi

Fr.: sous-stellaire   

1) Pertaining to a class of objects with a mass less than 8 percent that of the Sun.
2) → substellar point.

sub- + → stellar.

substellar limit
  حدّ ِ زیر-ستاره‌ای   
hadd-e zir-setâre-yi

Fr.: limite sous-stellaire   

The mass limit below which → hydrogen fusion cannot take place, and the cloud collapse cannot lead to the formation of a star. The limit is 0.075 → solar masses, corresponding to about 80 Jupiter masses.

substellar; → limit.

substellar object
  بر‌آخت ِ زیر-ستاره‌ای   
bart-e zir-setâre-yi

Fr.: objet sous-stellaire   

An object with a mass too small to sustain the → proton-proton chain and thus become a true star. See → brown dwarf.

substellar; → object.

substellar point
  نقطه‌ی ِ زیر-ستاره‌ای   
noqte-ye zir-setâre-yi

Fr.: point substellaire   

The point on the Earth, or other body, at which a particular star is directly overhead at a given time.

substellar; → point.

substellarity
  زیر-ستارگی   
zir-setâregi

Fr.: nature sous-stellaire   

The fact or condition, for an object, of not being capable to sustain the → hydrogen fusion because of its low mass (less than 0.08 → solar masses).

substellar + → -ity.

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.

violent interstellar environment
  پرگیر ِ اندر-اختری ِ سورا   
pargir-e andar-axtari-ye surâ

Fr.: environnement interstellaire violent   

A description of the interstellar medium justified by the presence of supersonic shock waves, massive star winds, turbulence, supernova explosions, etc.

violent; → interstellar; → environment.

young stellar object (YSO)
  بر آخت ِ ستاره‌ای ِ جوان   
barâxt-e setâreyi-ye javân

Fr.: objet stellaire jeune   

Any star that has evolved past the → protostar stage, but has not yet arrived on the → main sequence. There is a variety of YSOs depending on their age, mass, and environment, including → Herbig stars, → T Tauri stars, and, in general, compact infrared sources embedded in molecular clouds.

young; → stellar; → object.

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