Spherical Astronomy Problems And Solutions __link__

A global system using Declination (comparable to latitude) and Right Ascension (comparable to longitude) to fix stars in place despite Earth's rotation.

Spherical astronomy uses to determine the positions and motions of celestial bodies on the imaginary celestial sphere. Core Mathematical Foundations spherical astronomy problems and solutions

A star has a declination $\delta = -10^\circ$. At what Hour Angle ($H$) does it set for an observer at Latitude $\phi = +40^\circ$? A global system using Declination (comparable to latitude)