A fungus (/ËfÊÅÉ¡És/; plural: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from the other eukaryotic life kingdoms of plants and animals. A characteristic that places fungi in a different kingdom from plants, bacteria and some protists, is chitin in their cell walls.
The 11-year cycle of the number of sunspots was first demonstrated by Heinrich Schwabe (1789-1875) in 1843. There have been several periods during which sunspots were rare or absent, most notably the Maunder minimum (1645-1715), and less markedly the Dalton minimum (1795-1820) (Fig 2.8 in the book).
They're actually very bright. Sunspots are the result of complicated processes in the magnetic field of the sun. They make it hard for heat energy to convect from lower down in the sun to the surface. This means they are about 1500K cooler than the rest of the sun's surface, ie. about 30% cooller.