Sunspot cycle

1843 Sunspot cycle

The book of science

Tom Sharp

Heinrich Schwabe astronomy

Sunspot cycle

Patterns in the sky


Because Heinrich Schwabe was an apothecary, he had to work during the day, so he could not stay up all night to study the stars. Studying the sun was his recourse. Originally, he thought that a dark spot on the sun might be a sign of the passing of the planet that Urbain Le Verrier had proposed orbited the sun inside the orbit of Mercury.

The solar cycle is now known to be about 11 years on average, but varying between 9 and 14 years. Nevertheless, the cycle is associated with changes in solar radiation, solar flares, and coronal mass ejections, whoses effects are felt on the earth, so this was an important discovery. Alexander von Humboldt used Schwabe’s observations in the third volume of Kosmos in 1851.

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