Integration Guide — Data Sources
All data. All public.
Vedākṣha does not use proprietary data files, licensed ephemeris services, or undocumented algorithms. Every data source is public, cited, and linked. You can independently verify every number the library produces.
Source citations are embedded in the Rust source at the point of use — not just in documentation. The chapter, verse, or paper section is in the comment above the function.
JPL DE440 / DE441
NASA Jet Propulsion Laboratory Development Ephemeris 440 / 441
The definitive modern planetary ephemeris, produced by numerical integration of the equations of motion for the solar system bodies. DE440 is the current standard file. DE441 is the extended-range variant for historical and far-future calculations. Both are public domain and freely downloadable from the JPL Solar System Dynamics website.
Domain
Planetary positions
Coverage
DE440: 1550–2650 CE · DE441: ~13000 BCE – 17000 CE
License
Public domain. Released by JPL/NASA.
Precision
Sub-arcsecond agreement with JPL Horizons for all major bodies.
IAU 2006 Precession
International Astronomical Union Precession Model 2006 (Capitaine, Wallace & Chapront)
The current IAU standard for computing the precession of the equinoxes and the ecliptic. Vedākṣha uses IAU 2006 precession throughout its coordinate transformation pipeline to convert from ICRS (barycentric) to geocentric ecliptic coordinates and equatorial coordinates.
Domain
Ecliptic & equatorial coordinate transforms
Coverage
Applicable from J2000.0 ± several centuries
License
IAU standards. Open access.
Precision
Arcsecond-level agreement with SOFA/ERFA reference implementations.
IAU 2000B Nutation
International Astronomical Union Nutation Model 2000B (McCarthy & Luzum, 2003)
The 2000B truncated nutation series, comprising 77 luni-solar terms and 1 planetary term. Used by Vedākṣha to compute the true obliquity of the ecliptic and nutation in longitude — the small periodic perturbation of Earth's orientation relative to inertial space.
Domain
True ecliptic coordinates
Coverage
Continuous — algebraic series
License
IAU standards. Open access.
Precision
Agreement within 1 mas of IAU 2000A over the years 1995–2050.
Meeus — Astronomical Algorithms
Jean Meeus, Astronomical Algorithms, 2nd edition (Willmann-Bell, 1998)
The standard algorithmic reference for practical astronomical computing. Vedākṣha derives its Julian Day conversion, Greenwich Apparent Sidereal Time (GAST), Delta T approximation for historical dates, and various solar/lunar correction algorithms directly from Meeus. Every chapter is cited in the source code at the point of use.
Domain
Julian Day conversion, sidereal time, solar corrections
Coverage
N/A — algorithmic reference
License
Widely cited textbook. Algorithms in public domain.
Precision
Meeus algorithms are consistent with JPL Horizons to the level documented in the book.
BPHS — Brihat Parashara Hora Shastra
Brihat Parashara Hora Shastra (traditional; translated by G.C. Sharma and others)
The foundational text of Vedic astrology, attributed to the sage Parashara. Vedākṣha's implementations of Vimshottari dasha periods, nakshatra boundaries, yoga definitions, Shadbala strength components, and the 16 Shodasha Varga divisional charts are all sourced from BPHS. Chapter and verse references are embedded in the source code.
Domain
Vedic astrological algorithms
Coverage
All Vedic features: nakshatras, dashas, yogas, shadbala, vargas
License
Traditional text. Public domain.
Precision
Algorithmic precision; classical definitions are exact by construction.
Holden — Elements of House Division
Ralph William Holden, The Elements of House Division (Fowler, 1977)
The definitive algorithmic treatment of astrological house division. Vedākṣha implements all major house systems using the mathematical derivations in Holden, extended with the Sripathi house system from classical Vedic sources. The polar fallback to Whole Sign for extreme latitudes follows Holden's recommended practice.
Domain
House system algorithms
Coverage
Placidus, Koch, Regiomontanus, Campanus, Morinus, Equal, Whole Sign, and more
License
Published reference. Algorithms widely cited.
Precision
Agreement with professional astrological software for all tested locations and dates.
Hipparcos Star Catalogue
ESA Hipparcos Catalogue (ESA, 1997) — HIP main catalogue
The astrometric catalogue produced by the ESA Hipparcos space mission. Vedākṣha uses Hipparcos star positions (propagated to J2000.0 using proper motion) for fixed star placements in the ChartGraph FixedStar nodes. Integration is planned for a future release; the catalogue reference is included here for completeness.
Domain
Fixed star positions
Coverage
~118 000 stars; positions for epoch J1991.25
License
Public domain. Released by ESA.
Precision
Milliarcsecond-level astrometry for the included stars.
No Black Boxes
Every algorithm in Vedākṣha is traceable to a public, citable source. The library ships with no proprietary data files. The embedded DE440s is the same file downloadable from the JPL Solar System Dynamics FTP. If a number looks wrong, you can trace it back to the source and verify it against JPL Horizons or the SOFA/ERFA reference implementation.