Noun
the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day
Source: WordNetAstronomy and Astrophysics 105(2), 361, 1982, see equation 19. defined UT1 such that the observed sidereal day at the beginning of 2000 would be times a UT1 day of main s, which gives main s of UT1. Source: Internet
Because its rotation is so slow, Venus is very close to spherical. citation A Venusian sidereal day thus lasts longer than a Venusian year (243 versus 224.7 Earth days). Source: Internet
A mean solar day is, therefore, nearly 4 minutes longer than a sidereal day. Source: Internet
A semi-synchronous orbit has an orbital period of ½ sidereal day, i.e., 11 h 58 min. Source: Internet
A sidereal day (the period of rotation) lasts about 58.7 Earth days. Source: Internet
Earth's sidereal day also differs from its rotation period relative to the background stars by the amount of precession in right ascension during one day (8.4 ms). Source: Internet