Fixed stars such as those that make up the constellations are called fixed to distinguish them from the "wandering stars" or planets. In actuality, all stars are in motion relative the the Earth's rest frame. It is only because stars other than the sun are located very far away that they appear unmoving on the time scale of a human life. It is more accurate, therefore, to refer to these stars as "relatively fixed." The slow motion of a star relative to the celestial coordinate system imposed by astronomers is called its proper motion. Some tropical astrologers have cited the movement of these stars as a weakness of those forms of astrology that use the sidereal zodiac.
It is fairly uncommon for modern astrologers to use fixed stars in their delineations, but ancient and medieval astrologers almost always took them into account, especially those that are particularly bright and close to the ecliptic. Some of the stars most commonly considered in astrological judgments are Spica, Antares, Regulus, Aldebaran, Fomalhaut, the Pleiades, and Algol. The characteristics of the fixed stars were often described by astrologers as combinations of planetary qualities; for example, Spica is described by Ptolemy as having an influence similar to Venus and Mars.