The apparent motion of Sagittarius A * is very, very small, just one-600, 000th of what could be detected with the human eye, the astronomers said.
32.
The geocentric ecliptic system was the principal coordinate system for ancient astronomy and is still useful for computing the apparent motions of the Sun, Moon, and planets.
33.
The equation of time is then added to this constant rotation, producing a rotation of the tracker that keeps pace with the apparent motion of the Sun.
34.
The component along this axis of the Sun's apparent motion is a result of the familiar seasonal variation of the declination of the Sun through the year.
35.
Computer-controlled electric motors are commonly employed to allow the telescope to move in sync with the apparent motion of the sky, according to a pre-computed pointing model.
36.
The first geometrical, three-dimensional models to explain the apparent motion of the planets were developed in the 4th century BC by Eudoxus of Cnidus and Callippus of Cyzicus.
37.
In addition to following the daily East-West apparent motion of the Sun in the sky, the tracker must follow the Sun's seasonal apparent movements in the North-South direction.
38.
In 1947, research had been started at the Lick Observatory in California to study the Northern Milky Way's structure by determining the accurate positions and apparent motions of stars.
39.
Since the Earth is constantly rotating, telescopes and equipment are rotated in the opposite direction to follow the apparent motion of the stars overhead ( called diurnal motion ).
40.
The TBD approach may be applied both for pure detection when the tentative target displays a very small amount of apparent motion, as well as for actual motion tracking.
