diurnal motion


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Related to diurnal motion: sidereal day

diurnal motion

n
(Astronomy) motion that occurs during the day or daily, such as the diurnal rotation of the celestial sphere
References in classic literature ?
There was an astronomer, who had undertaken to place a sun-dial upon the great weathercock on the town-house, by adjusting the annual and diurnal motions of the earth and sun, so as to answer and coincide with all accidental turnings of the wind.
The four directions on the horizon were associated with the four kukulu, or supporting pillars of heaven, with the diurnal motion of the sun, and with the motion of the trade-winds.
Since, by definition, there should be no retrograde quasi-diurnal motion of the pole in either reference frames, we chose only one complex integration constant (initial position of the pole) and constrain the other one so that the free diurnal motion disappears.
The biggest problem is atmospheric refraction, which increasingly slows the apparent diurnal motion of stars as they appear farther from the zenith.