The Star Trek quadrant system divides the Milky Way into four sections. What is at (0,0) or (0,0,0) if need be? Have astronomers tried to estimate where these zero coordinates would be?
Well, to quote Memory Alpha:
According to Star Trek Maps, the XYZ spatial coordinates 0,0,0 used by the Federation are those of a central navigation beacon located near the core worlds of the Federation. The galactic XYZ values are in a grid in relation to this central beacon. Units in the grid are parsecs. The first value X is the distance towards (positive) or away from (negative) the center of the galaxy. The second value Y is the distance towards the left "Alpha Quadrant" direction (positive) or the right "Beta Quadrant" direction (negative). The third value Z is the distance in the galactic north direction upwards (positive) or galactic south downwards (negative) away from the galactic plane.