Lunar nodes (brief)

The lunar nodes are where the Moon’s orbital plane crosses the ecliptic. In astrology they are treated as calculation points (not physical bodies), often linked to eclipse geometry and axis themes.

North and South Node

North Node (☊, Rahu in Jyotish) — one intersection; the Moon’s orbit crosses the ecliptic from south to north.
South Node (☋, Ketu) — opposite point, 180° away.

BirthInput.bodies may include NorthNode and SouthNode; they appear in the default chart body set in astrorust_core.

Computation in this stack

Node longitudes come from the ephemeris implementation (orbital plane intersection / mean node formula depending on backend). They share the same ecliptic longitude → sign → house pipeline as planets (planet-positions).

For sidereal charts, node longitudes are ayanamsa-shifted like other bodies in calculate_sidereal.

Interpretive note (non-calculation)

Western and Vedic traditions assign rich mythic meaning to the nodes; the provider only supplies consistent degrees, signs, and houses given birth data.

References

Lunar node — Wikipedia
Orbital node — general definition