Spörer's law predicts the variation of
sunspot
Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. S ...
latitudes during a
solar cycle
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surf ...
. It was discovered by the English astronomer
Richard Christopher Carrington
Richard Christopher Carrington (26 May 1826 – 27 November 1875) was an English amateur astronomer whose 1859 astronomical observations demonstrated the existence of solar flares as well as suggesting their electrical influence upon the Eart ...
around 1861. Carrington's work was refined by the German astronomer
Gustav Spörer.
At the start of a sunspot cycle, sunspots tend to appear around 30° to 45° latitude on the
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
's surface. As the cycle progresses, sunspots appear at lower and lower latitudes, until they average 15° at
solar maximum
Solar maximum is the regular period of greatest solar activity during the Sun's 11-year solar cycle. During solar maximum, large numbers of sunspots appear, and the solar irradiance output grows by about 0.07%. On average, the solar cycle tak ...
. The average latitude of sunspots then continues to drift lower, down to about 7° and then while the old sunspot cycle fades, sunspots of the new cycle start appearing at high latitudes.
See also
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Solar variation
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surfa ...
*
Wolf number
The Wolf number (also known as the relative sunspot number or Zürich number) is a quantity that measures the number of sunspots and groups of sunspots present on the surface of the Sun.
History
Astronomers have been observing the Sun recordin ...
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Joy's law (astronomy)
In astronomy, Joy's law describes the distribution of sunspots in active region
An active region is a temporary region in the Sun's atmosphere characterized by a strong and complex magnetic field. They are often associated with sunspots and are ...
References
Solar phenomena
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