Solar case: Lyα linear polarization as a function of the apparent height of the line-of-sight above the solar limb, at the position angle 80° with respect to the solar rotation axis. Circles: case of the zero magnetic field. Crosses: case of the dipolar magnetic field (see text). This figure replaces Fig. 7 of Derouich et al. (2010), except for the case of the additional equatorial current sheet, which we did not compute.