Rudolf Wolf
Wolf, Rudolf
Born July 7, 1816, in Fällenden, near Zurich; died Dec. 6, 1896, in Zurich. Swiss astronomer. Specialist in the study of sunspots and in the history of astronomy.
Wolf became director of the Bern Observatory in 1847, a professor at the University of Zurich in 1855, and director of the Zurich Observatory in 1864. Wolf determined that the average duration of a cycle of changes in the number of sun-spots is equal to 11 1/9 years, and he established the existence of a connection between this period and variations in the earth’s magnetic field. He also introduced the so-called Wolf number to characterize solar activity.
WORKS
Geschichie der Astronomic. Munich, 1877.Handbuch der Astronomic, ihrer Geschichte und Literatur, vols. 1-2. Zurich, 1890-93.