Sidereal
Encyclopedia
Sidereal, of the stars, may refer to:
- Measurements of time:
- Sidereal timeSidereal timeSidereal time is a time-keeping system astronomers use to keep track of the direction to point their telescopes to view a given star in the night sky...
- Sidereal day
- Sidereal month
- Sidereal yearSidereal yearA sidereal year is the time taken by the Earth to orbit the Sun once with respect to the fixed stars. Hence it is also the time taken for the Sun to return to the same position with respect to the fixed stars after apparently travelling once around the ecliptic. It was equal to at noon 1 January...
- Sidereal time
- Sidereal periodOrbital periodThe orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of an object orbiting a star - Sidereal astrologySidereal astrologySidereal and tropical are astronomical terms used to describe two different definitions of a "year". They are also used as terms for two systems of ecliptic coordinates used in astrology....
- Sidereus NunciusSidereus NunciusSidereus Nuncius is a short treatise published in New Latin by Galileo Galilei in March 1610. It was the first scientific treatise based on observations made through a telescope...
, or Sidereal Messenger, a scientific work by Galileo GalileiGalileo GalileiGalileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...