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: 46 Search : object
stellar object
  بر‌آخت ِ ستاره‌ای   
barâxt-e setâre-yi

Fr.: objet stellaire   

Any of a class of → astronomical objects which is thought to evolve into a → star or is a descendant of a star.

stellar; → object.

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.

Thorne-Zytkow object (TŻO)
  بر‌آخت ِ Thorne-Żytkow   
barâxt-e Thorne-Żytkow

Fr.: objet Thorne-Żytkow   

A theoretical class of → stellar objects in which a → neutron star core is surrounded by a large and diffuse envelope. TŻOs are expected to form as a result of the evolution of two → massive stars in a → close binary, with the neutron star forming when the more massive star explodes as a → supernova. During subsequent evolution of the system, the expanding envelope of the companion may lead to a common envelope state and the spiral-in of the neutron star into the core of its companion. Alternately, a TŻO may be produced when a newly-formed neutron star receives a supernova "kick" velocity in the direction of its companion and becomes embedded. Supergiant TŻOs are predicted to be almost identical in appearance to → red supergiants (RSGs). The best features that can be used at present to distinguish TŻOs from the general RSG population are the unusually strong → heavy element and → lithium lines present in their spectra, products of the star's fully → convective envelope linking the → photosphere with the extraordinarily hot burning region in the vicinity of the neutron star core. These objects are thought to be extremely rare, with as few as 20-200 of them predicted to exist in the Galaxy at present, though some authors have doubted whether such an object could survive the merger with the envelope intact. A candidate is HV 2112 (Levesque et al., 2014, MNRAS, arXiv:1406.0001; Beasor et al., 2018, MNRAS, arXiv:1806.07399).

Thorne K. S., Żytkow A., 1975, ApJ 199, L19.

trans-Neptunian object (TNO)
  بر‌آخت ِ ترا-نپتونی   
barâxt-e tarâ-Nneptuni

Fr.: objet trans-neptunien   

A member of a class of objects in orbit around the Sun at a larger distance than the distance between Neptune and the Sun. This includes several → dwarf planets, such as → Eris, → Pluto, and many small solar system bodies.

trans-; → Neptune; → object.

unidentified flying object (UFO)
  بر‌آخت ِ پرنده‌ی ِ نا-ایدانیده، پدیده‌ی ِ هوا-فضایی ِ نا-ایدانیده   
barâxt-e parande-ye nâ-idânidé, padide-ye havâ-fazâyi-ye nâ-idânidé

Fr.: Objet Volant Non Identifié (OVNI)   

Any flying object or phenomenon that cannot be identified by the observer.

unidentified; fly; M.E. flien; O.E. fleogan (cf. O.H.G. fliogan, O.N. flügja, M.Du. vlieghen, Ger. fliegen); → object.

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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