apparentVSOP87 function
Apparent longitude of the Sun using VSOP87 (high accuracy).
Applies nutation and aberration to trueVSOP87.
Implementation
({double lon, double lat, double range}) apparentVSOP87(
Planet earth, double jde) {
final true_ = trueVSOP87(earth, jde);
final n = nut.nutation(jde);
final a = aberration(true_.range);
return (lon: true_.lon + n.dPsi + a, lat: true_.lat, range: true_.range);
}