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).
Sunspots occur when vertical magnetic field lines on the surface of a star bond to conducting gases. The gases are then unable to flow along the surface horizontally. Less gas motion via convection means less energy from below. This is the reason why sunspots are also darker than their surroundings.