public static void calc_geocentric(ref double longitude, ref double latitude, ref double rektaszension, ref double declination, double date)
{
//var
double epsilon; //: extended;
double delta_phi; //: extended;
double alpha, delta; //: extended;
calc_epsilon_phi(date, out delta_phi, out epsilon);
longitude = GPMath.putIn360(longitude + delta_phi);
alpha = GPMath.arctan2Deg(GPMath.sinDeg(longitude) * GPMath.cosDeg(epsilon) - GPMath.tanDeg(latitude) * GPMath.sinDeg(epsilon), GPMath.cosDeg(longitude));
delta = GPMath.arcsinDeg(GPMath.sinDeg(latitude) * GPMath.cosDeg(epsilon) + GPMath.cosDeg(latitude) * GPMath.sinDeg(epsilon) * GPMath.sinDeg(longitude));
rektaszension = alpha;
declination = delta;
double xg, yg, zg;
xg = GPMath.cosDeg(longitude) * GPMath.cosDeg(latitude);
yg = GPMath.sinDeg(longitude) * GPMath.cosDeg(latitude);
zg = GPMath.sinDeg(latitude);
alpha = GPMath.arctan2Deg(yg * GPMath.cosDeg(epsilon) - zg * GPMath.sinDeg(epsilon), GPMath.cosDeg(longitude) * GPMath.cosDeg(latitude));
}
