Solar Storms and You!

HD103095, type G8IV, period = 7.3 years

Activity 3: Sunspot Activity on Other Stars


Since the 1970's, astronomers have been studying dozens of other stars that resemble the Sun in size and temperature. By monitoring the month to month changes in the brightness of these stars, using the light they emit at specific wavelengths, they can investigate how storms on these stars ebb and flow over time.These 'stellar activity cycles' are caused the same processes that our own Sun's sunspot cycle is, but they have many different properties that make them unique.


Students will analyze and compare stellar activity graphs to determine how similar or different they are to the solar sunspot cycle.


Student page


  1. Group students into either pairs or teams of four. Read the introduction to the students concerning the current issues in astronomy having to do with solar activity.
  2. Review with the students an example of how graphs may be similar and different. Be sure to mention shape, distribution, highs, lows, scale, axis, and time frame.
  3. Provide students with sufficent time to compare the stellar activity cycle graphs with the solar sunspot graphs.
  4. Have the groups present their findings to the class.

Key Terminology

Sunspot: A dark spot on the Sun's surface indicating intense magnetic activity and solar storms.
Sunspot Cycle: The change in the rise and fall of sunspot numbers over a roughly 11 - year cycle.


Explain that astronomers do not yet know why the sun has a sunspot cycle, or whether these cycles are permanent in the history of the sun, or come and go with time. By studying other stars we can learn just how typical our sun is, and study the possible factors that influence these cycles, such as the star's mass, temperature, and age.

Related Web Resources

Have a look at more stellar data on activity cycles by visiting the Mount Wilson Observatory HK Project. Plenty of graphs of the activity cycles of other sun-like stars to check on how typical our sun is as a star of similar spectral type ( G2 V). Note the wide range in cycle durations, with some stars not showing evidence for any cycle at least not yet!

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This activity was developed by the NASA, IMAGE/POETRY 
Teacher and Student Consortium. 
For more information, and a list of other resources, visit 
the IMAGE/POETRYweb site.