来自法语 sidereal,恒星的，来自拉丁语 sideris,星星的，所有格形式于 sidus,星星，星辰，词 源同 consider,desire.
- 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.
- 1. The sidereal year is not used to construct a calendar.
- 2. A sidereal day is about 4 minutes shorter than a solar day.
- 3. A sidereal day is shorter than a mean solar day by 3 minutes and 56 seconds.
- 4. Tropical year, and sidereal year are two different concepts.
- 5. A solar day is four minutes longers than a sidereal day.
[ sidereal 造句 ]