Spica is Alpha Virginis. It is particularly useful for checking coordinate conventions because its bright point is close enough to the ecliptic for a longitude comparison to be less misleading than for a polar star. The residual latitude should still be recorded.
| IAU name | Spica |
|---|---|
| Designation | Alpha Virginis · HR 5056 |
| Constellation | Virgo |
| Visual magnitude in IAU table | 0.98 |
| J2000 right ascension | 201.298247° |
| J2000 declination | -11.161319° |
| Tropical longitude on 1 Jan 2026 | 24.21° Libra |
| Ecliptic latitude on 1 Jan 2026 | -2.06° |
Reading the coordinates
At the stated 2026 reference instant, the projected tropical position is 24.21° Libra, with ecliptic latitude -2.06°. Its latitude is comparatively modest. Even here, a matching longitude is a one-dimensional test: check the exact orb and the full sky angle before describing the alignment.
Right ascension and declination locate Spica on an equatorial sky map; the tropical position rotates and projects that J2000 direction into a dated ecliptic frame. Precession changes the printed zodiac longitude over centuries. It does not move the star from Virgo to a different astronomical constellation. This is why an undated “fixed degree” should be checked against its source.
A useful research question
How much of the claimed match survives when the full angular separation is calculated? A clear answer identifies the named star, the date, and the method of comparison. Ptolemy’s surviving astrological discussion groups stars by constellation figure and assigns symbolic qualities; it is a historical text, not a measured guide to personal outcomes.
Test a recorded birth moment →
Position calculation
The IAU table identifies the named star and gives its right ascension and declination at J2000. Astronomy Engine rotates that direction to the true ecliptic and equinox of a chosen date. The displayed tropical longitude is the angle around the ecliptic; latitude records how far above or below that plane the star lies. The reference date on this page is 1 January 2026 at 12:00 UTC.
The calculation does not propagate individual stellar proper motion, parallax, or perspective effects. It is intended for modern reference dates, not ancient reconstructions. A planet sharing a projected longitude with a star can still be far away on the sky. The chart locator shows that full angular separation and limits automatic matches to stars within 40° of the ecliptic.