The Sun crosses the constellation Ophiuchus every year, roughly December 7 to December 18 — the sign the traditional zodiac left out. This calculator checks your exact birth moment against the real IAU boundary, for your Sun and every planet, inside a full 13-sign chart.
Free full chart with a written snapshot interpretation — no account or payment needed.
Five systems. Your composition in 60 seconds.
Ophiuchus isn't an invention — it's a real constellation on the ecliptic between Scorpius and Sagittarius. The twelve-sign zodiac skips it for tidiness. True sidereal astrology, which follows the actual sky, doesn't.
Being 'an Ophiuchus' doesn't erase your tropical sign; the two systems measure different things. Synthesis shows your chart in both — the seasonal zodiac you grew up with, and the 13-sign real-sky version — so you can compare instead of choosing blind.
A real constellation the Sun passes through every year, roughly December 7 to December 18 — between Scorpius and Sagittarius. The traditional zodiac left it out to keep a tidy twelve; true sidereal astrology, which follows the actual sky, includes it as a 13th sign.
If you were born roughly between December 7 and December 18, your true-sidereal Sun likely falls in Ophiuchus — this calculator checks your exact birth moment against the real IAU boundary rather than a fixed date range, and checks every other planet too.
It doesn't replace anything — it adds a layer. Your tropical sign is measured from the seasons and stays what it is; your true-sidereal sign is measured from the actual constellations, where Ophiuchus exists. Synthesis shows both so you can compare rather than choose.
Yes. True Sidereal mode uses the real IAU constellation boundaries, which are unequal in width and include Ophiuchus — the full chart, not just the Sun, is computed against all 13.
Yes — the complete 13-sign chart with houses and aspects is free, with no account or payment needed.