Magnetic field topology of θ Aur derived from the Cr Stokes IQUV LSD profiles. The star is shown at five rotational phases, which are indicated above each spherical plot column. The inclination angle is i = 123°.7. The spherical plots show the maps of field modulus (panel a), horizontal field (panel b), radial field (panel c), and field orientation (panel d). The contours over spherical maps are plotted with a step of 0.1 kG. The thick line and the vertical bar indicate the positions of the rotational equator and the visible pole, respectively. The colour bars give the field strength in kG. The two different colours in the field orientation map correspond to the field vectors directed outwards (red) and inwards (blue).