Schwabe, Samuel Heinrich (zäˈmōĕl hĪnˈrĭkh shväbˈə) [key], 1789–1875, German apothecary and amateur astronomer. In the hope of discovering a new planet between Mercury and the sun, he made daily observations and tallies of sunspots. In 1843, after 17 years of sunspot counts, he noted a periodicity of 10 or 11 years in their totals. His discovery initiated modern solar studies and investigations of the effects of sunspots on terrestrial magnetism, weather, and plant and animal growth rates.
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