Post-concussion syndrome. Post-concussion syndrome, also known as postconcussive syndrome or PCS, is a set of symptoms that may continue for weeks, months, or a year or more after a concussion â a mild form of traumatic brain injury (TBI).
The Equatorial (Celestial) Coordinate System. Equatorial coordinates, also called simply celestial coordinates, are the standard coordinate system for the sky. It is meant for the fixed sphere of the stars within which the Earth and Sun move.
Any point of the celestial (i.e. the position of a star or planet) can be referenced with a unique Right Ascension and Declination. The celestial sphere has a north and south celestial pole as well as a celestial equator which are projected from reference points from the Earth surface.