DiurnalPathAtHorizon computes the angle of the path a celestial object relative to the horizon at the time of its rising or setting.

EclipticAtEquator computes the angle between the ecliptic and the parallels of ecliptic latitude at a given ecliptic longitude.

EclipticAtHorizon computes how the plane of the ecliptic intersects the horizon at a given local sidereal time as observed from a given geographic latitude.

ParallacticAngle returns parallactic angle of a celestial object.

ParallacticAngleOnHorizon is a special case of ParallacticAngle.