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: 8 Search : spectroscopic
double-lined spectroscopic binary
  درین ِ دوخطه‌ی ِ بیناب‌نماییک   
dorin-e doxatte-ye binâbnemâyik

Fr.: binaire spectroscopique à double raies   

Same as → double-lined binary.

double; → line; → spectroscopic; → binary.

spectroscopic
  بیناب‌نمایی، بیناب‌نماییک   
binâbnemâyi, binâbnemaayik

Fr.: spectroscopique   

Of or relating to → spectroscopy.

spectro-; → -scopy; → -ic.

spectroscopic binary
  دُرین ِ بیناب‌نمایی   
dorin-e binâbnemâyi

Fr.: binaire spectroscopique   

A binary system that cannot be resolved by a telescope, but can be identified by means of the Doppler shift of the spectral lines. As stars revolve, they alternately approach and recede in the line of sight. This motion is shown up in their spectra as a periodic oscillation or doubling of spectral lines.

spectroscopic; → binary.

spectroscopic degeneracy
  واگنی ِ بیناب‌نمایی   
vâgeni-ye binâbnemâyi

Fr.: dégénérescence spectroscopique   

The situation in which spectroscopic features in a certain optical region are not sensitive enough to distinguish adjacent → luminosity classes, for instance → dwarf stars from → giant stars.

spectroscopic; → degeneracy.

spectroscopic Hertzsprung-Russell diagram (sHRD)
  نمودار ِ بینابنماییک ِ هرتسپرونگ-راسل   
nemudâr-e binâbnemâyik-e Hertzsprung--Russell

Fr.: diagramme spectroscopique de Hertzsprung-Russell   

A spacial → Hertzsprung-Russell diagram (HRD) which is independent of distance and extinction measurements. The sHRD is derived from the classical HRD by replacing the luminosity (L) to the quantity ℒ = T 4eff/g which is the inverse of the flux-weighted gravity introduced by Kudritzki et al. (2003). The value of ℒ can be calculated from stellar atmosphere analyses without prior knowledge of the distance or the extinction. In contrast to the classical Teff-log g diagram (→ Kiel diagram), the sHRD sorts stars according to their proximity to the → Eddington limit, because ℒ is proportional to the Eddington factor Γ = L/LEdd according to the relation ℒ = (1/4πσG)(L/M) = (c/(σκ)Γ, where σ is the → Stefan-Boltzmann constant, κ is the electron → scattering  → opacity in the stellar envelope, and the other symbols have their usual meanings (Langer, N., Kudritzki, R. P., 2014, A&A 564, A52, arXive:1403.2212, Castro et al., 2014, A&A 570, L13.

spectroscopic; → H-R diagram.

spectroscopic mass
  جرم ِ بیناب‌نمایی   
jerm binâbnemâyi

Fr.: masse spectroscopique   

The stellar mass derived from → gravity (g) and radius (R), expressed by M = gR2/G, where G is the → gravitational constant. Spectroscopic mass conveys the actual mass of the star, in contrast with its → initial mass.

spectroscopic; → mass.

spectroscopic parallax
  دیدگشت ِ بیناب‌نمایی   
didgašt-e binâbnamâyi

Fr.: parallaxe spectroscopique   

The measurement of a stellar distance by the absolute magnitude derived from the luminosity criteria of the spectrum and the apparent magnitude of the star.

spectroscopic; → parallax.

spectroscopic variable
  ورتنده‌ی ِ بیناب‌نمایی   
vartande-ye binâbnemâyi

Fr.: variable spectroscopique   

A → variable star that displays changes in its → spectrum. In such stars line intensities may vary and new lines may appear. Examples include → AG Carinae, HD 108, HD 191612, and HD 148937.

spectroscopic; → variable.