astrootldr

Sources

Primary references used across this site. Computational sources are authoritative for numbers; interpretive sources are cited per tradition.

Computational and astronomical references

  • Astronomy Engine

    MIT-licensed ephemeris engine. VSOP87 + ELP-2000 theories. Primary computational source.

  • NASA JPL Horizons

    Authoritative ephemeris. Used for spot-checking Astronomy Engine output.

  • Swiss Ephemeris

    GPL/commercial ephemeris by Astrodienst. Reference standard for astrological calculation.

  • IAU Sky Coordinates

    International Astronomical Union official constellation boundaries.

Hellenistic and classical Western

Modern Western

Vedic / sidereal