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.
Celestial Equator (religion, spiritualism, and occult) The celestial equator, also termed the equinoctial, is the terrestrial equator imaginarily projected outward from Earth and onto the background of the stars (i.e., against the backdrop of the celestial sphere). Because of the tilt of the Earth on its axis, the celestial equator intersects the ecliptic at an angle of 23Â½Â°.