pleiades-eclipse

Global geocentric solar and lunar eclipse computation for the pleiades astrology workspace, derived from validated Sun and Moon positions.

What it provides

For any time in the 1900-01-01 … 2100-01-01 window (the packaged ephemeris boundary), pleiades-eclipse returns the solar and lunar eclipses that occur, each carrying:

• Eclipse type — solar (total / annular / hybrid / partial) or lunar (penumbral / partial / total)
• Instant of greatest eclipse — the moment to cast a chart on
• Magnitude — fraction of the disk covered (geocentric)
• Gamma — least distance of the shadow axis from Earth's centre, in Earth radii
• Saros series number
• Eclipsed longitude — apparent tropical ecliptic longitude of date at greatest eclipse (no ayanamsa; sidereal conversion is the façade layer's job)
• Greatest-eclipse location (solar only) — geographic sub-shadow point; lunar eclipses have no location

Not provided: local / per-observer circumstances (local magnitude, contact times, visibility path). This is a global/geocentric product.

Window and data-bound

Coverage is strictly 1900-01-01 through 2100-01-01 (JD 2 415 020.5 … JD 2 488 069.5, TDB), bounded by the packaged Sun/Moon ephemeris. Four NASA-canon eclipses falling in mid/late 2100 are excluded as uncomputable with the packaged data.

Validation

The fail-closed validate-eclipses gate (in pleiades-validate) recomputes every in-window eclipse from NASA's Five Millennium Canon of Solar/Lunar Eclipses (Espenak/Meeus) and enforces:

Approximately 908 eclipses pass all tolerances. One documented knife-edge eclipse (1948-05-09, Saros 137, annular vs hybrid at magnitude ≈ 1.0) is allowlisted for the exact-type check only; its time, magnitude, Saros, and longitude are still enforced. The eclipsed-longitude reference is computed independently (NASA canon + Skyfield/DE440), so the gate genuinely validates accuracy.

Quick start

use pleiades_data::packaged_backend;
use pleiades_eclipse::{EclipseEngine, EclipseFilter};
use pleiades_types::{Instant, JulianDay, TimeScale};

let engine = EclipseEngine::new(packaged_backend());
let after = Instant::new(JulianDay::from_days(2_451_545.0), TimeScale::Tdb);
let next = engine.next_eclipse(after, EclipseFilter::All).unwrap();
assert!(next.is_some());