Noun
measured by the diurnal motion of stars
Source: WordNetBoth solar time and sidereal time make use of the regularity of Earth's rotation about its polar axis, solar time following the sun while sidereal time roughly follows the stars. Source: Internet
Glossary, s.v. hour angle, hour circle, sidereal time. Source: Internet
Local sidereal time at any locality differs from the Greenwich sidereal time value of the same moment, by an amount that is proportional to the longitude of the locality. Source: Internet
Nowadays, UT is the observed orientation of the Earth relative to an inertial reference frame formed by extra-galactic radio sources, modified by an adopted ratio between sidereal time and solar time. Source: Internet
When one moves eastward 15° in longitude, sidereal time is larger by one sidereal hour (note that it wraps around at 24 hours). Source: Internet