The maps represented here are not actually solar images, rather, they are a subtraction of two dopplergrams. The sun oscillates in a natural frequency of 5 minutes, therefore half of a solar oscillation is 2.5 minutes. The velocity maps have been computed by subtracting two dopplergrams separated 3 minutes apart...close enough. As a result, rotation of the sun has been removed, and relative velocities are left over, in the representation of red and blue regions.
|Crimean Observatory||60' Tower - MTW|
|May 12, 1996 - (15:10-15:13) UT||May 12, 1996 - (15:10-15:13) UT|