Free Astrology Tool

Fixed Stars Calculator

Astrolium's fixed star calculator finds Regulus, Algol, Spica, and 20+ fixed stars conjunct your natal planets within 2°, with traditional interpretations.

Birth Data
Finds fixed star conjunctions within 2° of your natal planets.

What is Fixed Stars?

Fixed stars bring a different quality to natal interpretation than planets. Where planets describe processes — ongoing cycles of energy — fixed stars carry singular, concentrated meanings. A conjunction between a natal planet and a fixed star imprints that planet with the star's nature.

The Royal Stars — Regulus, Aldebaran, Antares, and Fomalhaut — carry the strongest traditional associations. Regulus (Leo 0°) brings leadership and royal favour, with one classical caveat: revenge destroys the gift. Algol (Taurus 26°) is the most feared star in traditional practice, associated with violent transformation. Spica (Libra 24°) is one of the most fortunate stars for mental gifts.

Astrolium's fixed star calculator checks 23 named fixed stars from two preset lists (essential and traditional) against every natal planet and angle, reporting any conjunction within a 2° orb. The tool accepts birth date, time, and place, then returns ecliptic longitudes for stars including the four Royal Stars (Regulus, Aldebaran, Antares, Fomalhaut), the Pleiades cluster, Algol, Spica, Vega, Arcturus, Sirius, and additional Ptolemaic stars. Each conjunction is paired with the traditional interpretation tied to that specific planet-star combination, drawing on Ptolemy's catalogue and later medieval commentary. Most charts show zero to three active conjunctions because tight 2° orbs are rare. Practitioners use it during natal interpretation to flag concentrated imprints that supplement standard planet-and-sign delineation, particularly when a Royal Star sits on an angle or a luminary. Calculations use Swiss Ephemeris with sub-arcsecond accuracy on tropical ecliptic longitudes adjusted for stellar proper motion. Free, no account required.

Reading your fixed star conjunctions

Most charts have zero to three active fixed star conjunctions within 2°. If you have none, that's normal — fixed stars require precise alignment. If you have one, it tends to be significant.

Read the conjunction in terms of both planets. Mars conjunct Regulus is different from Jupiter conjunct Regulus or Moon conjunct Regulus, even though the star's core meaning stays constant. The planet's nature filters the star's expression.

Traditional warnings and modern perspective

Traditional astrology treated malefic fixed stars (Algol, Antares, the Pleiades) with serious concern. Modern practice tends to interpret these as intense, concentrated energy requiring conscious handling rather than as curses.

The intensity is real; the determinism is not. A Mars-Algol conjunction describes a person who likely encounters extreme force — in themselves or from others — and needs to develop a conscious relationship with it.

Related

Frequently asked questions

What are fixed stars in astrology?
Fixed stars are actual stars — far beyond our solar system — whose positions on the ecliptic align with zodiac degrees. Unlike planets, they barely move over a human lifetime. When a natal planet falls within 1–2° of a fixed star, the star's traditional nature blends with the planet's. The conjunction is the primary aspect used.
Which fixed stars does Astrolium check?
The calculator checks 23 fixed stars from two preset lists: essential (the Royal Stars Regulus, Aldebaran, Antares, Fomalhaut; the Pleiades cluster; Algol, Spica, Vega, Arcturus, Sirius, and others) and traditional (additional stars from Ptolemy's star catalogue). Any conjunction within 2° is reported with interpretation.
How tight does a fixed star conjunction need to be?
Traditional practice uses very tight orbs — 1° or less for most stars, up to 2° for the brightest (magnitude 1 or less). Algol and Regulus are typically given 2° orbs due to their brightness and strength. Astrolium uses a standard 2° orb for all stars in this calculator.

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