Position Angle

This is an angle that describes the direction in relationship to north, usually used for Comet tails and double stars. On a scale from 0 degrees to 360 degrees:

North = 0 degrees, or 360 degrees

East = 90 degrees

South = 180 degrees

West = 270 degrees

Which way is north? The easiest way to figure this out is to let whatever object you are viewing drift our the eyepiece field of view,... the direction it is going is west. If you are using a reflecting telescope then north is counter-clockwise from west and a refractor or cassegrain scope will have north in a clockwise direction from west.

Heisenberg might have slept here.