perigee function

double perigee(
  1. double jde
)

Longitude of perigee.

Implementation

double perigee(double jde) {
  return mod2pi(toRad(horner(j2000Century(jde),
      [83.3532465, 4069.0137287, -0.01032, -1 / 80053.0, 1 / 18999000.0])));
}