The frame of reference for the actual position is the absolute position in the galaxy.
The frame of reference for the apparent position is absolute position in the galaxy as observed from the earth which is rotating ~24 hours per 360 degrees.
1,077 posted on 09/18/2008 9:50:12 AM PDT by Fichori
(ironic: adj. 1 Characterized by or constituting irony. 2 Obamy getting beat up by a girl.)