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geocentric parallaxSee diurnal parallax.
(or diurnal parallax), the angle whose vertex is at the center of a celestial body and whose sides extend to the center of the earth and to the point of observation on the earth’s surface. (See.)
geocentric parallax[¦jē·ō¦sen·trik ′par·ə‚laks]
The difference in the apparent direction or position of a celestial body, measured in seconds of arc, as determined from the center of the earth and from a point on its surface; this varies with the body's altitude and distance from the earth. Also known as diurnal parallax.