Also found in: Dictionary, Thesaurus, Acronyms, Wikipedia.
Related to sidereal day: synodic month
sidereal day:see sidereal timesidereal 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.
..... Click the link for more information. .
sidereal dayThe 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.
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.