sidereal
pronunciation
How to pronounce sidereal in British English:
UK [saɪˈdɪəriəl]
How to pronounce sidereal in American English:
US [saɪˈdɪriəl]
-
- Adjective:
- of or relating to the stars or constellations
- (of divisions of time) determined by daily motion of the stars
Word Origin
- sidereal (adj.)
- also siderial, 1630s, "star-like;" 1640s, "of or pertaining to the stars," earlier sideral (1590s), from French sidereal (16c.), from Latin sidereus "starry, astral, of the constellations," from sidus (genitive sideris) "star, group of stars, constellation," probably from PIE root *sweid- "to shine" (cognates: Lithuanian svidus "shining, bright"). Sidereal time is measured by the apparent diurnal motion of the fixed stars. The sidereal day begins and ends with the passage of the vernal equinox over the meridian and is about four minutes shorter than the solar day, measured by the passage of the sun over the meridian.
Example
- 1. The sidereal year is not used to construct a calendar .
- 2. You can see for the sidereal day , the earth has gone through one complete rotation ( with respect to the background stars ) .
- 3. So , the tropical year is a little bit shorter than the sidereal year .
- 4. A sidereal day is shorter than a mean solar day by 3 minutes and 56 seconds .
- 5. Sidereal time is said to be on average 4 minutes more per day , than solar time astronomers use sidereal time to locate known objects in the night sky .