Sidereal, meaning "of the stars", may refer to:
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Sidereal time
Sidereal time (as a unit also sidereal day or sidereal rotation period) (sidereal ) is a timekeeping system that astronomers use to locate celestial objects. Using sidereal time, it is possible to easily point a telescope to the proper coord ...
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Sidereal day
Sidereal time (as a unit also sidereal day or sidereal rotation period) (sidereal ) is a timekeeping system that astronomers use to locate celestial objects. Using sidereal time, it is possible to easily point a telescope to the proper coord ...
* Sidereal
month
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Sidereal year
A sidereal year (, ; ), also called a sidereal orbital period, is the time that Earth or another planetary body takes to orbit the Sun once with respect to the fixed stars.
Hence, for Earth, it is also the time taken for the Sun to return to the ...
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Sidereal period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, ...
of an object orbiting a star
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Sidereal and tropical astrology
'' Sidereal'' and ''tropical'' are terms used to describe two different definitions of a year, applied in sidereal solar calendars or tropical solar calendars. In astrology, they refer to two different systems of ecliptic coordinates used to ...
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