Learn Jyotish
The sidereal zodiac and the ayanamsa
Why Vedic signs sit about 24° behind Western ones, and what the Lahiri ayanamsa measures.
Western astrology anchors Aries 0° to the March equinox — a seasonal point. Vedic astrology anchors the zodiac to the fixed stars. Because Earth's axis slowly wobbles (precession, one full cycle in roughly 25,800 years), the equinox drifts backwards against the stars by about 50 arcseconds a year.
The ayanamsa is the angle between those two starting points. VYOMIRA uses the Lahiri (Chitrapaksha) ayanamsa — the standard adopted by India's Calendar Reform Committee — which places the star Spica (Chitra) at 0° Libra. In 2026 it is a little over 24°.
We compute it with the IAU 1976 precession model from a fixed reference epoch, the same definition used by Swiss Ephemeris. Every chart shows the exact ayanamsa value used, so you can compare with any other software.
Keep reading
- What is a Janam Kundli (Vedic birth chart)?
- Sade Sati: what it is — and what it isn't
- Rahu and Ketu, the lunar nodes
- Manglik (Kuja) dosha, explained calmly
Updated 5 November 2026 · VYOMIRA by Cloudisoft