Spörer's_law
Spörer's law
Empirical law for solar active regions
In solar physics, Spörer's law is an empirical law for the variation of heliographic latitudes at which solar active regions form during a solar cycle.[1] It was discovered by the English astronomer Richard Christopher Carrington around 1861.[2] Carrington's work was refined by the German astronomer Gustav Spörer.
At the start of a solar cycle, active regions tend to appear around 30° to 45° latitude on the Sun's surface. As the cycle progresses, they appear at lower and lower latitudes, until they average 15° at solar maximum. The average latitude then continues to drift lower, down to about 7° and then while the old sunspot cycle fades, active regions of the new cycle start appearing at high latitudes.[3]
