Local Sidereal Time
From ExoDictionary
Local Sidereal Time
Local hour angle of the vernal equinox, expressed in time units; the arc of the celestial equator, or the angle at the celestial pole, between the upper branch of the local celestial meridian and the hour circle of the vernal equinox, measured westward form the upper branch of the local celestial meridian through 24 hours.
References
This article is based on NASA's Dictionary of Technical Terms for Aerospace Use
