Editing Hour angle (section)

==Sidereal hour angle==
The sidereal hour angle (SHA) of a body on the celestial sphere is its angular distance west of the [[Equinox (celestial coordinates)|March equinox]] generally measured in degrees. The SHA of a star varies by less than a minute of arc per year, due to [[precession]], while the SHA of a planet varies significantly from night to night. SHA is often used in [[celestial navigation]] and navigational astronomy, and values are published in nautical [[almanac]]s.{{fact|date=June 2021}}