Low-level astronomical calculations for coordinate transformations.

Pure Rust implementation of IAU 2000/2006 standards for celestial mechanics: rotation matrices, nutation/precession models, angle handling, and geodetic conversions. No runtime FFI.

[dependencies]
celestial-core = "0.1"

use celestial_core::nutation::NutationIAU2006A;
use celestial_core::constants::J2000_JD;

// Compute nutation at J2000.0
let nutation = NutationIAU2006A::new().compute(J2000_JD, 0.0).unwrap();
println!("Δψ = {:.6}″", nutation.delta_psi * 206264.806); // radians to arcsec
println!("Δε = {:.6}″", nutation.delta_eps * 206264.806);

• serde — Enables serialization for Angle and other types

• Two-part Julian Dates: Functions accept (jd1, jd2) to preserve precision. Typically jd1 = 2451545.0 (J2000.0) and jd2 is days from epoch.
• Radians internally: All angular computations use radians. The Angle type provides conversion methods for degrees/HMS/DMS display.
• Stateless models: Nutation and precession calculators have no internal state. Call compute(jd1, jd2) with any epoch.

Licensed under either of:

• Apache License, Version 2.0
• MIT License

See the repository for contribution guidelines.