In this laboratory students will calculate the Sun's rotation by tracking sunspots in Sun images. By the end of this Science Case students will understand how the Sun moves and will know how to calculate velocities by tracking targets in time-spaced images. Also they will calculate the size of a sunspot and learn to compare sizes in astronomical images. And finaly they will determine where in the solar cycle we are and learn about the Sun's cycle.

In all human cultures the Sun played a major role and was thus observed by astronomers. Sunspots were observed already more than 2000 years ago by Chinese and Greek scientists. In the 19th century it became clear that the number of sunspots was related to the solar activity and undergoing a cyclic change. Since then sunspots are counted systematically by various observatories around the globe and define cycle of solar activity. With the CESAR solar observatory, taking pictures every week, you can participate in the world wide campaign of sunspot counting.

Teacher's Guide	Student's Guide	Quizzes	Web Tools

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Booklet	Resources
The booklet	Calculate the size of a sunspot Heliographic coordinates Calculate the rotation period Formula sheet Calculations and results blank sheet CESAR Solar Observatory SOHO-NASA/ESA Quiz for teachers How does the Sun's magnetic field work? Space weather What is wrong with the sun? Number of sunspots per year