Show where he discovered nuclear reactions play an important role. Label the core, photosphere, chromosphere, and corona. Look at the movie of the surface of the Sun showing solar granulation. Describe what you see, and offer an explanation. An image showing the magnetic field strength everywhere on the surface of the sun is called a magnetogram.
Astronomers use magnetograms when they study sunspots.
What is a sunspot. Make a drawing. Explain the sunspot cycle. When will the next minimum and maximum occur. Explain how a magnetogram is obtained.