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: 2 Search : phase angle
initial phase angle
  زاویه‌ی ِ فاز ِ آغازین   
zâviye-ye fâz-e âqâzin

Fr.: angle de phase initial   

The value of the phase corresponding to the origin of time. Same as the → epoch angle.

initial; → phase; → angle.

phase angle
  زاویه‌ی ِ فاز   
zâviye-ye fâz (#)

Fr.: angle de phase   

1) Physics: Of a → periodic wave, the number of suitable units of angular measure between a point on the wave and a reference point.
2) Astro.: For an object in the solar system, the angle "Sun-object-Earth" that is, the angle between the Sun and the observer as seen from the given object. It is 0° when the object is fully illuminated, 90° when the object is half-illuminated (like the Moon at first quarter and last quarter), and 180° when the object is between Earth and the Sun.
3) More generally, the angle between star light incident onto a related revolving object and the light reflected from the object to the observer (Earth).

phase; → angle.