A rough count of these objects is given by a formula which features a constant denoted C, or the "personal reduction coefficient.
A rough count of these objects is given by a formula which features a constant denoted C, or the "personal reduction coefficient." The distribution of these objects, which are the subject of the Zurich number formula, is plotted on so-called "butterfly diagrams" in which time is on the x-axis and latitude is on the y-axis. Samuel Schwabe first noted that the number of these objects varies with a period of about (*) 11 years, though they were noticeably absent during both the Spörer and Maunder Minima. About 4,000 degrees Celsius is the temperature of these phenomena, which consist of a central region called an umbra and an annular region called the penumbra. Fluctuations in the solar magnetic field cause, for 10 points, what darkened regions of the Sun?
A rough count of these objects is given by a formula which features a constant denoted C, or the "personal reduction coefficient.
sunspots