An Etymological Dictionary of Astronomy and Astrophysics

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فرهنگ ریشه‌شناختی اخترشناسی-اخترفیزیک

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Greenwich Apparent Sidereal Time (GAST)
  زمان ِ اختری ِ پدیدار ِ گرینویچ  
zamân-e axtari-ye padidâr-e Greenwich
Fr.: temps sidéral apparent de Greenwich  

The → Greenwich Mean Sidereal Time corrected for → nutation. Therefore, it is measured with respect to the → true vernal equinox. GAST and GMST differ by the → equation of the equinoxes.

See also: → Greenwich Meridian; → apparent; → sidereal; → time.