Astronomical Laboratory
Scientific calculators of positional astronomy with documented precision, continuous validation against JPL Horizons, and open code for auditing. Analytical engine based on ELP-2000/82B, IAU 2000A and VSOP87D, with no external service dependency.
Tools
Position and phenomena calculators. Each tool exposes complete scientific inputs and auditable outputs.
Lunar Calculator
Topocentric position, phase, libration, eclipses, supermoons, multicultural calendars, lunar folklore.
ELP-2000/82B full 36+ inputs 25+ outputsPlanets (7)
Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune. Position, magnitude, phase, elongation in real time.
VSOP87D full 12104 terms ~arcsecSky Chart
Stereographic polar projection of the local sky. Moon and Sun in topocentric coordinates.
SVG server-rendered TopocentricLunar Globe
Lunar disc with exact phase, solar terminator and optical libration in longitude and latitude.
ELP-2000 SVGStellar Atlas
Top bright stars (Hipparcos) + 88 official IAU constellations.
88 constellations HipparcosAsteroids & Comets
Ceres, Vesta, Apophis, Bennu, Halley, Hale-Bopp, NEOWISE. 22 asteroids + 10 comets.
JPL SBDB Kepler engineEclipse Calculator (map)
Complete Besselian prediction with global visibility map. The classification engine is already validated against NASA Espenak.
Besselian engine OK Map under constructionTechnical documentation
Everything under the hood of the engine: validation, methodology, cited sources, technical glossary.
📊 Precision
Validation table against JPL Horizons. Typical errors per output, temporal coverage, declared limitations.
📐 Methodology
Full calculation chain: ELP-2000/82B, VSOP87D, IAU 2000A, Espenak-Meeus, Bennett, Saemundsson, WGS84.
📚 Sources and Bibliography
Scientific papers with DOI, reference books, official datasets. ABNT standard.
📖 Glossary
Technical terms in positional astronomy, celestial mechanics, geodesy and astronomical time.
📝 Changelog
Engine semantic versioning. Change history, precision improvements, new models.
Laboratory philosophy
Evergreen with no external API
All calculations run on analytical series and static data. No dependency on online services at runtime. Data is updated through controlled releases, not via continuous feed.
Continuous validation
Each release goes through a regression suite against JPL Horizons (NASA/JPL) and canonical examples from the Meeus 1998 book. Typical errors published at /precisao.
Sources cited in every output
Each engine algorithm references the source paper, book or standard. It cites Chapront-Touze 1983, IERS Conventions 2010, Bretagnon-Francou 1988, Espenak-Meeus 2006, Bennett 1982, IAU SOFA.
Honest temporal coverage
Useful window of maximum precision: 1900-2100. Extended with controlled degradation up to 4000 BC and 3000 AD via Espenak-Meeus. Limits published, not hidden.
Auditable outputs
Each output includes the time scales (UTC, UT1, TAI, TT, TDB), the reference frame (ICRS, GCRS, CIRS), and the apparent corrections applied (nutation, annual aberration).
Input sanitization
Each input parameter has scientifically justified limits, with cited source (ICAO standard atmosphere for pressure, IERS for EOP, weather records for temperature).