Reference:
• Kuhn, Karl F., 1994: In Quest Of The Universe, West Publishing Company, St. Paul, 568 pp.

Related Links:
• NASA Marshall Space Flight Center Solar Physics Website
• The Exploratorium: the museum of science, art and human perception
• Galileo's sunspot drawings, from the Galileo Project, Rice University

Sunspots and the Solar Max
History
What exactly is a sunspot?
The Butterfly Diagram
The Solar Wind
References