Calculating the Sun's Angular Velocity -- Example

Tracking the movement of a sunspot helps us determine the Sun's rate of rotation.

This is the template

Look at your sun sketches and pick a sunspot group which is easy to see and which appears over a period of several days. Make a transparent copy of the template, lay it over your images, and figure out how many degrees your spot group has moved. Like this:

[Amara -- We need 2 images of a sunspot group, with the grid superimposed on them. Beneath each we need a time-stamp. Can you create these???]

So, the spot group has moved 90 (whatever) degrees in 7.5 days.
To compute the Sun's rotation period:

The Sun's Angular velocity = degrees the spot has covered / time it took for the spot to travel

angular velocity = 90 / 7.5  = 12 degrees/day

Sun's rotation period = 360 degrees / angular velocity

So, in this example, we find the Sun's rotation period = 360/12 = 30 days

 Return to the Angular Velocity exercize