calculate_parallactic_angle#

lsst.ts.observatory.control.calculate_parallactic_angle(location, lst, target)#

Calculate the parallactic angle.

Parameters:

  • location (astropy.coordinates.EarthLocation) – Observatory location.

  • lst (astropy.coordinates.Angle) – Local sidereal time.

  • target (astropy.coordinates.ICRS) – The observing target coordinates.

Returns:

Parallactic angle.

Return type:

Angle

Notes

The parallactic angle is the angle between the great circle that intersects a celestial object and the zenith, and the object’s hour circle [1].