sidereal day


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Related to sidereal day: synodic month

sidereal time

sidereal time (ST), time measured relative to the fixed stars; thus, the sidereal day is the period during which the earth completes one rotation on its axis so that some chosen star appears twice on the observer's celestial meridian. Because the earth moves in its orbit about the sun, the sidereal day is about 4 min shorter than the solar day (see solar time). Thus, a given star will appear to rise 4 min earlier each night, so that different stars are visible at different times of the year. The local sidereal time of an observer is equal to the hour angle of the vernal equinox.
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sidereal day

The interval between two successive passages of a catalog equinox across a given meridian. It is divided into 24 sidereal hours. The sidereal day is 3 minutes 56 seconds shorter than the mean solar day.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

Sidereal day

(religion, spiritualism, and occult)

A sidereal day is the period of time it takes for Earth to complete one rotation on its axis with respect to a fixed point in space. Specifically, a sidereal day begins and ends when the local meridian for any given location on Earth passes through 0° Aries (the vernal point). Because of the motion of Earth around the Sun, sidereal days are slightly shorter than ordinary solar days. A sidereal day is 23 hours 56 minutes and 4.09 seconds in length; a sidereal hour is ½4 the length of a sidereal day.

The Astrology Book, Second Edition © 2003 Visible Ink Press®. All rights reserved.

sidereal day

[sī′dir·ē·əl ′dā]
(astronomy)
The time between two successive upper transits of the vernal equinox; this period measures one sidereal day.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

sidereal day

sidereal dayclick for a larger image
The period between two successive transits of a particular meridian on the earth by the first point of Aries or successive transits of the vernal equinox. Because the first point of Aries is not fixed in space and it precesses along the equinoctial 11.26” of ecliptic by arc each year, the sidereal day measured relative to Aries is minutely shorter than that measured relative to a fixed point in space. These two days are known as practical and theoretical sidereal days, respectively. The time over the upper branch of any meridian is equal to 24 h of mean sidereal time or 23 h 56 min 4.09054 s of mean solar time.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved

sidereal day

Slightly less than the 24 hours of a solar day (23 hours, 56 minutes, 4.1 seconds). Used in astronomy, sidereal means "when a star crosses the meridian" (the meridian is an imaginary circle around the earth). For example, at noon, the sun and stars are overhead, but 23 hours, 56 minutes and 4.1 seconds later, the earth is back in relation to the stars, but not the sun, which takes approximately four minutes longer.
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References in periodicals archive ?
It is still unclear how the picture would change with the "sidereal day" taken into consideration.
Regular changes in the fine structure of histograms revealed in the experiments with collimators which isolate beams of alpha-particles flying at certain directions
It is there that he took the time to compare the phase of distant ceasium clocks and discovered the periodic phase shift signal with a sidereal day period.
and thus is the sidereal day. This result, like the one of D.
The Roland De Witte 1991 experiment (to the memory of Roland De Witte)
3) there are two peaks--one corresponds to sidereal day (1436 minutes), the second, which is less expressed, corresponds to solar day (1440 minutes).
Experiments with rotating collimators cutting out pencil of [alpha]-particles at radioactive decay of [sup.239]Pu evidence sharp anisotropy of space
A geosynchronous orbit, for those of you who aren't yet conversant, is one with an orbital period of one sidereal day. This equates to precisely 23 hours, 56 minutes and four seconds - the same orbital period as the earth.
THIS MUCH I KNOW
Splitting of the local-time peak in Fig 1c is similar to splitting of the daily period in two peaks with periods equal to solar and sidereal days [9-11].
Experimental investigations of the existence of a local-time effect on the laboratory scale and the heterogeneity of space-time
and receive the angular oscillation period 1/[[omega].sub.Sun] = 12.7 sidereal days that is the first harmonic of the equatorial rotation period 25.4 days of the Sun.
The surface gravity acceleration of Saturn [g.sub.Saturn] = = 10.4 m/[s.sup.2] corresponds with an oscillation period of c/gSaturn = 334 sidereal days that is in the range of the duration of lightning storms on Saturn which appear once every 30 Earth years.
Mars and Mercury have similar surface gravity accelerations of about 3.7 [ms.sup.-2] that corresponds to an oscillation period of c/3.7 [ms.sup.-2] = 938 sidereal days near the attractor node [64; 2] of the F (1) calibrated on the electron:
The surface gravity acceleration of Jupiter [g.sub.jupiter] = = 24.79 [ms.sup.-2] corresponds to an oscillation period of c/[g.sub.Jupiter] = 140 sidereal days near the main attractor node of the F calibrated on the electron:
Gravity as Attractor Effect of Stability Nodes in Chain Systems of Harmonic Quantum Oscillators

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