Moon phases and declination
Phase is Sun–Moon elongation; declination is a separate equatorial coordinate. · 8 min
Phase angle
RAINBOW stores moonPhaseAngle as Sun–Moon elongation in ecliptic longitude: 0° new, 90° first quarter, 180° full, 270° last quarter.
Sun–Moon elongation at 2024-01-25 17:54 UTC. 0° = new, 180° = full.
179.99°
FullDeclination
Declination is J2000 equatorial, not ecliptic latitude. Parallel-of-declination experiments use the difference of two bodies’ declinations as a feature threshold — an astronomy-native cut, not a cultural rule.
Key points
- The January 2024 full moon (~180° phase) is a fixture.
- Lunar nodes are unimplemented: they are not in the ephemeris body list.
- Moon-phase event studies still need a sample-size gate. Slow outer-planet waves belong in the waveform track, not here.
Method
A “full moon ±6°” condition is a window on elongation. It is not a claim that lunations move prices.
References
- astronomy-engine MoonPhase
- Meeus, Astronomical Algorithms — Meeus J., Astronomical Algorithms, 2nd ed., Willmann-Bell, 1998