Sidereal Time
Related Category: Astronomy: General
(ST), time measured relative to the fixed stars; thus, ...
Sidereal time
Sidereal time vs solar time. Below left, a distant star (the small red circle) and the Sun are at culmination, on the local meridian. Centre: only the distant star is at culmination (a mean sidereal day).
sidereal time
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Sidereal time is based on how long it takes for a celestial object, like a star, to return to the same position in the sky after the Earth rotates.
Local sidereal time is the most useful form of since it gives the of a transiting celestial object at a given location. To compute the current local sidereal time LST, consult the current Astronomical Almanac. Look up the "G.
sidereal time, sidereal day: see time (types of)
sigil: an inscribed or painted symbol considered to have magical power. The term is sometimes used to refer to the Zodiac and planetary symbols (see Appendix I and Appendix VIII respectively).
SIDEREAL TIME - Time measured in relation to the fixed stars: the length of a sidereal day is 23 hr, 56 min, 4.09 sec of mean solar time.
SIDERITE - An obsolete term for an iron meteorite.
Sidereal time is a measure of the position of the Earth in its rotation around its axis, or time measured by the apparent diurnal motion of the vernal equinox, which is very close to, but not identical to, the motion of stars....
Sidereal time A method of keeping time which uses the motion of the stars rather than the Sun. One sidereal day is equal to 23hrs56m4s of normal solar time.
Sidereal Time The hour angle of the First Point of Aries. It is time measured with respect to the stars. See the tutorial on Time.
Solar Time Time measured with respect to the Sun. See the tutorial on Time.
Sidereal Time
(ST) The measure of time defined by the apparent diurnal motion of the catalog equinox; hence a measure of the rotation of the Earth with respect to the stars rather than the Sun.
Siderite ...
Sidereal time -- Time relative to the stars other than the sun.
SIRTF -- Space Infrared Telescope Facility.
Sidereal time. The local time measured according to the apparent rotation of the celestial sphere. When the Vernal Equinox crosses the observer's meridian the sidereal time is 0 hours.
Sidereal. With respect of the stars.
LOCAL SIDEREAL TIME
Local sidereal time (abbreviated LST) is local time measured by the apparent motion of the stars (instead of the motion of the Sun).
Sidereal time ( Star Time) - Whenever the Earth has completed 366.2422 rotations with reference to the Stars, one year has past. When the Earth has completed 365.2422 rotations with reference to the Sun, one year has past.
SIDEREAL TIME
Sidereal time is time measured relative to the stars (the period between successive conjunctions with any star) instead of relative to the motion of the Sun).
Sidereal time is time measured relative to the stars (the period between successive conjunctions with any star) instead of relative to the motion of the Sun).
Sidereal time is useful to astronomers and navigators who deal with the stars. It is not that useful to people in other walks of life. Sidereal time is different from the time people see on clocks.
mean sidereal time (NASA SP-7, 1965) Sidereal time adjusted for nutation to eliminate slight irregularities in the rate. mean solar day (NASA SP-7, 1965) The duration of one rotation of the earth on its axis, with respect to the mean sun.
Hour angle
The sidereal time that has elapsed since the object was on the meridian (hour angle west, positive) or until it will again be on the meridian (hour angle east, negative).
local sidereal time (NASA SP-7, 1965) (abbr LST)
Local hour angle of the vernal equinox, expressed in time units; the arc of the celestial equator, or the angle at the celestial pole, ...
A coordinate system or frame of reference defined in the vicinity of the earth in which Newtons first law of motion is valid; that is, a nonrotating and nonaccelerating reference frame. [Silk90]
Local Sidereal Time ...
Technically, the sidereal time is defined as the length of time since the vernal equinox has crossed the local celestial meridian.
An ephemeris may also provide data on astronomical phenomena of interest to astrologers and astronomers such as eclipses, apparent retrogradation/planetary stations, planetary ingresses, sidereal time, ...
The precession of the Earth's rotation axis introduces another difference between sidereal time and solar time. This is seen in how the year is measured. A year is defined as the orbital period of the Earth.
The reason for this choice is that the earth rotates at an approximately constant rate (see sidereal time).
A highly accurate clock that keeps either sidereal time or Universal Time. Formerly, such instruments were checked by timing the passage of clock stars across the meridian using a meridian or transit circle and a book of clock errors.
Of a celestial object as seen from a particular location, the difference between the local sidereal time and the right ascension (H.A. = L.S.T. - R.A.).
H-R diagram - (n.)
Hertzsprung-Russell diagram.
21-22 Tau Asterope is the combined name for Sterope I and Sterope II. 23 Tau Merope 27 Tau Atlas 28 Tau Pleione
Sky Charts
Sidereal Time Northern Hemisphere Southern Hemisphere
0100 hours ...
 See also: Time, Earth, Sun, Astronomy, Sky
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