From the February 2008 issue

How to classify sunspots

Use this guide to determine the type of sunspot you're observing.
By | Published: February 21, 2008
In “How to observe the Sun,” which appeared in the April 2008 issue of Astronomy, I outlined how you can observe the Sun. Since telescopic solar observing began, astronomers have counted sunspots. They also have divided sunspots into types.