These 17th-century drawings of the sun by Kepler add fire to solar cycle mystery

image via Space.com

July 30, 2024, 2:59 PM

• •Renaissance astronomer Johannes Kepler's sunspot drawings from 1607 show the tail-end of the solar cycle
• •The drawings offer a key to resolving the controversy on the duration of solar cycles at the beginning of the 17th century
• •Kepler's observations may show the transition zone between solar cycles, which the study pegged between 1607 and 1610.

Johannes Kepler's sunspot drawings are the oldest sunspot records with known dates. They show the tail-end of the solar cycle and may offer a key to resolving the controversy on the duration of solar cycles at the beginning of the 17th century.

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