cycle function
Returns the JDE of the start of the given Carrington synodic rotation.
c is the Carrington cycle number. Result is dynamical time.
Implementation
double cycle(int c) {
final cf = c.toDouble();
final jde = 2398140.227 + 27.2752316 * cf;
final m = (281.96 + 26.882476 * cf) * math.pi / 180;
final s2m = math.sin(2 * m);
final c2m = math.cos(2 * m);
return jde + 0.1454 * math.sin(m) - 0.0085 * s2m - 0.0141 * c2m;
}