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: 22 Search : refract
relative refractive index
  دیشن ِ شکستی ِ بازانی   
dišan-e šekasti-ye bâzâni

Fr.: indice de réfraction relatif   

The ratio of the sine of the angle of incidence to the sine of the angle of refraction for a ray passing out of one of the media into the other.

relative; → refractive; → index.

Yerkes refractor
  شکست‌گر ِ یرکیز   
šekastgar-e Yerkes

Fr.: réfracteur de Yerkes   

The largest → refracting telescope and the last of the great refractors with a lens diameter of 102 cm (f/d = 19), completed in 1897. The lens was ground by American telescope builders Alvan Clark & Sons. Used mainly for both visual and photographic studies of double stars, it is typical of the long-tube refractors traditionally employed in such work.

After Yerkes Observatory; → refractor.

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