🔠Astronomy & Calculations
Astrology is built on precise astronomical calculations. This category explains the science behind planetary positions, coordinate systems, and why Qronology uses IAU SOFA standards for maximum accuracy.
Available Now
The dedicated astronomy deep dives are still in progress. For now, start with the published guide below, then use this page as a roadmap for the calculation topics that are coming next.
Published
Astronomy Fundamentals
A live guide covering the navagraha, orbital speed, and the difference between heliocentric, geocentric, and topocentric viewpoints.
Roadmap for Astronomy
The cards below describe planned topics but do not link out until the content exists.
Planned
Retrograde Motion
Why planets appear to move backward from Earth's perspective. Covers orbital mechanics, retrograde frequencies for each planet, and the astrological significance of retrograde periods.
Planned
Coordinate Systems
Ecliptic coordinates, equatorial coordinates, and the practical difference between heliocentric, geocentric, and topocentric reference frames in chart construction.
Planned
Precession of the Equinoxes
Earth's axial wobble (precession) causes the vernal equinox to shift backward through the zodiac at ~1° per 72 years. This is why tropical and sidereal zodiacs have diverged by ~24° today.
Planned
Ayanamsas (Zodiac Offsets)
The ayanamsa is the correction factor between tropical and sidereal zodiacs. Different schools use different ayanamsas: Lahiri (official Indian standard), Raman, Krishnamurti (KP), Fagan-Bradley, etc.
Planned
Ephemeris Data
Ephemerides are tables of planetary positions. Modern ephemerides (JPL DE440/DE441) use numerical integration of gravitational equations. Learn how Qronology sources and processes this data.
Planned
IAU SOFA Standards
The International Astronomical Union's Standards of Fundamental Astronomy library provides reference implementations for astrometry and celestial mechanics. Qronology uses SOFA for rigorous calculations.
Suggested Learning Path
We recommend reading topics in this order:
- Coordinate Systems — Understand how positions are measured.
- Precession — Learn why zodiacs drift apart.
- Ayanamsas — See how different schools correct for precession.
- Ephemeris Data — Understand where planetary positions come from.
- IAU SOFA — See why Qronology uses professional-grade tools.