In astrology the term fixed star is used to refer to stars that lie outside of the Earth’s solar system.
The phrase arises from the fact that the planets were originally referred to as “wandering stars” (planetes asteres) in ancient Greek, because the planets were seen to move against the backdrop of the night sky over time. This is in contrast with the other stars in the night sky, which seem to remain fixed and unmoving. Thus, the planets and the two luminaries were referred to as wandering stars, and the rest were referred to as fixed stars.
Despite the fact that people tend to use the word “planet” rather than “wandering star” in modern times, astrologers continue to use the phrase “fixed stars” in order to refer to stars that lie outside of our solar system.
Astrologers tend to put the most emphasis on bright fixed stars of the first magnitude, such as Regulus, Spica, Sirius, and Algol.