| English term or phrase: Sidereal time | Sidereal time
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For the novel Sidereal Time, see Christopher Meredith.
Astronomers use sidereal time (pronounced /saɪˈdɪ.riːɔːl/ /ˈtaɪ.m/) as a way to keep track of the direction in which their telescopes need to be pointed to view any given star in the night sky. Just as the Sun and Moon appear to rise in the east and set in the west, so do the stars.
A sidereal day is approximately 23 hours, 56 minutes, 4.091 seconds (23.93447 hours or 0.99726957 SI days), corresponding to the time it takes for the Earth to complete one rotation relative to the vernal equinox. The vernal equinox itself precesses very slowly in a westwards direction relative to the fixed stars, completing one revolution every 26,000 years approximately. As a consequence, the misnamed sidereal day, as "sidereal" is derived from the Latin sidus meaning "star", is some 0.008 seconds shorter than the earth's period of rotation relative to the fixed stars. The longer true sidereal period is called a stellar day by the International Earth Rotation and Reference Systems Service (IERS). It is also referred to as the sidereal period of rotation.
Había encontrado tiempo sideral, pero me parece que no es lo mismo.
Muchas gracias,
Laura. |
| Laura DKudoZ activityQuestions: 272 ( 5 open) ( 34 closed without grading) Answers: 194
Argentina
| Local time: 06:12
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The translation workplace 
peer agreement (net): +3
