LSD proflies of Stokes Q in blue and U in red. The red and blue lines represent the brightness distribution that better fits the observed profile. The observation dates are given in the bottom right of the figure. Stokes V is represented in green and has been shifted down and had its amplitude multiplied by 5 so that the profiles can be seen better. The vertical dashed lines represent, from left to right, the velocity, υ₀, and the velocity of the star, υ_*, adopted in our model.