XIII. Use Sun Spots to Measure the Rotation of the Sun.

1. You will need access to a small telescope equipped with a good quality solar filter or a method of safely projecting the Sun’s image. (Pretty much any telescope or even binoculars can be used to project the Sun’s image onto a screen.) Under no circumstances should you ever view the Sun through a telescope or binoculars without proper safety equipment. Total blindness will result. If there is any doubt whatsoever about your equipment, please bring it in for the instructor to see and check out.
2. Monitor the Sun once every few days until you see a nice sun spot near the edge of the Sun.
3. Make careful drawings of the Sun with the position of the sun spot carefully drawn on the image. Determine how many days it takes to move across the disk of the Sun. If your sun spot started part way across the Sun you will need to account for the offset from the edge. Your instructor can help you with this. From this information you can determine how long it takes the Sun to rotate on its axis (at that latitude).
4. Your report should include a careful description of the project, how you took your data and what your results were. Look up the actual rotation period of the Sun and compare that with your results.