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: 3 Search : T Tauri star
classical T Tauri star
  ستاره‌ی ِ T-گاو ِ کلاسیک   
setâre-ye T-Gâv-e kelâsik

Fr.: étoile T Tauri classique   

A → T Tauri star in which → accretion from a → circumstellar disk is responsible for ultraviolet and infrared excess emission and for a moderate to strong emission line spectrum superimposed on the photospheric spectrum. Classical T Tauri stars probably evolve into → weak-line T Tauri stars when their disks are fully accreted by the stars.

classical; → T Tauri star.

T Tauri star
  ستاره‌ی ِ T-گاو   
setâre-ye T-Gâv

Fr.: étoile T Tauri   

A member of a class of young stellar objects of roughly 1 solar mass showing strong → infrared excess emission attributed to → circumstellar disks and found within or close to molecular clouds. T Tauri stars are → protostars in the final stages of formation to become a stable → main sequence star. The nuclear reactions in their core have not yet stabilised and the stars are known for the variability of their brightness. See also → classical T Tauri star, → weak-line T Tauri star.

T Tauri; → star.

weak-line T Tauri star
  ستاره‌ی ِ T-گاو با خط‌های ِ نزار   
setâre-ye T-Gâv bâ xatthâ-ye nezâr

Fr.: étoile T Tauri à raies faibles   

A T Tauri star that lacks strong emission lines in its optical spectrum, and lacks both strong → stellar wind and → infrared excess. These objects are believed to be → pre-main sequence stars without obvious signs for disk → accretion. Weak-line T Tauri stars result from the evolution of → classical T Tauri stars.

weak; → line; → T Tauri star.