English: Stellar Parallax diagram

The apparent motion of a near by star is a small ellipse in the sky relative to background stars over the period of a year. The angle representing major axis radius of the elliptical path is the parallax angle.

The minor axis radius angle is simply related to the direction of the star relative to the earth's orbital axis. Stars near the north and south poles will make perfect circles, while stars near the ecliptic will make flat ellipses.