sun method

({double b, double l}) sun(
  1. double lambda,
  2. double beta,
  3. double delta,
  4. Planet earth,
)

Selenographic coordinates of the Sun.

Implementation

({double l, double b}) sun(
    double lambda, double beta, double delta, Planet earth) {
  final app = solar.apparentVSOP87(earth, jde);
  final deltaR = delta / (app.range * au);
  final lambdaH = app.lon +
      math.pi +
      57.296 * _d2r * deltaR * math.cos(beta) * math.sin(app.lon - lambda);
  final betaH = deltaR * beta;
  return lib(lambdaH, betaH);
}