) of 18h and +20°. If the Local Sidereal Time (LST) is 20h, what is the star’s Altitude ( ) and Azimuth ( Find the Hour Angle (H):
These formulas and constants are used to calculate the positions of celestial objects and to correct for various effects in spherical astronomy.
Angle at $P$ = hour angle $H$ (for upper culmination). Angle at $Z$ = $360^\circ - A$ if azimuth measured from north westward, but conventionally we use $A$ measured from north eastward. We adopt: Angle at Z = $A$ (azimuth) only after careful quadrant check.
Distance equals cap R cross d (in radians) equals 6400 cross 1.518 is approximately equal to 9715 km
