Schwabe, Samuel Heinrich

Samuel Heinrich Schwabe, (born Oct. 25, 1789, Dessau, Anhalt—died April 11, 1875, Dessau), amateur German astronomer who discovered that sunspots vary in number in a cycle of about 10 years; he announced his findings in 1843, after 17 years of almost daily observations. Schwabe also made (1831) the first known detailed drawing of the Great Red Spot on Jupiter. He was awarded the Gold Medal of the Royal Astronomical Society in 1857 and was elected a foreign member of the Royal Society in 1868—a singular honour for an amateur scientist at that time.