Magnetic field structure and distribution of helium on He-peculiar stars

The periodic variation of the equivalent width of Hei lines and of the magnetic field in six Bp stars is modeled by the oblique rotator model. The position of the magnetic poles and the structure of the helium distribution has been determined from the magnetic field observations and the line strength measurements of the Hei 4026 line. A comparison between the helium surface distribution and the structure of the magnetic field has been carried out.