Zeeman effect

nityah

Hi,

I would like to know how the Zeeman effect can cause a change in the velocity of a particular emission from the sun. I do know the equation that relates the change in the wavelength given by

Δλ = e/4 pi * c * (mass of electron) * λ2 * B

Do I need to make use of the Doppler effect if I need to know the relative velocity? The problem is, how do I find out the initial velocity cos I do not have the frequency of the emission.