This activity of the sun may be measured in various ways, but probably the most satisfactory system is that devised by Wolf of Zurich, and is known as the Wolf Sun-Spot Numbers. These are computed by the formula: r = k (lOg + f) where r is theanbsp;...

Title | : | A Laboratory Manual of Astronomy |

Author | : | Hazel Marie Losh, Robert Methven Petrie |

Publisher | : | - 1934 |

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