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- Dictionarysidereal day
noun
- 1. the time between two consecutive transits of the First Point of Aries. It represents the time taken by the earth to rotate on its axis relative to the stars, and is almost four minutes shorter than the solar day because of the earth's orbital motion.
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Viewed from the same location, a star seen at one position in the sky will be seen at the same position on another night at the same time of day (or night), if the day is defined as a sidereal day (also known as the sidereal rotation period).
Jun 10, 2012 · A sidereal day measures the rotation of Earth relative to the stars rather than the sun. It helps astronomers keep time and know where to point their telescopes without worrying about where...
In day. The sidereal day is the time required for the Earth to rotate once relative to the background of the stars—i.e., the time between two observed passages of a star over the same meridian of longitude. The apparent solar day is the time between two successive transits…. Read More.
The sidereal day is the time it takes for the Earth to complete one rotation about its axis with respect to the ‘fixed’ stars. By fixed, we mean that we treat the stars as if they were attached to an imaginary celestial sphere at a very large distance from the Earth.
Earth's rotation period relative to the precessing mean vernal equinox, named sidereal day, is 86 164.090 530 832 88 seconds of mean solar time (UT1) (23 h 56 m 4.090 530 832 88 s, 0.997 269 566 329 08 mean solar days). Thus, the sidereal day is shorter than the stellar day by about 8.4 ms.
The sidereal day, of 23 hours 56 minutes and 3.93 seconds, is 3 minutes 50 seconds shorter than the mean solar day, because the movement of the Earth in its solar orbit is imposed on its rotational motion.
Sidereal time, time as measured by the apparent motion about the Earth of the distant, so-called fixed, stars, as distinguished from solar time, which corresponds to the apparent motion of the Sun. The primary unit of sidereal time is the sidereal day, which is subdivided into 24 sidereal hours,
The meaning of SIDEREAL DAY is the interval between two successive transits of a point on the celestial sphere (such as the vernal equinox) over the upper meridian of a place : 23 hours, 56 minutes, 4.1 seconds of mean time. How to use sidereal day in a sentence.
Solar vs. Sidereal Day. . The Earth rotates on its axis relative to the sun every 24.0 hours mean solar time, with an inclination of 23.5 degrees from the plane of its orbit around the sun. Mean solar time represents an average of the variations caused by Earth's non-circular orbit.
The sidereal day is 23 h 56 m 4.1 s, slightly shorter than the solar day because the Earth 's orbital motion about the Sun means the Earth has to rotate slightly more than one turn with respect to the "fixed" stars in order to reach the same Earth-Sun orientation.
