2004A&A...424..237R

We present a Doppler Image of the oxygen abundance distribution over the surface of the star θ Aur. The symmetry of the oxygen distribution appears to be consistent with the magnetic field observations such that the oxygen is highly depleted at the magnetic poles. In contrast to the star ε UMa, where the oxygen displayed undepleted solar abundance in a band around the magnetic equator, for θ Aur the instances of more normal solar levels of abundance occur in bands midway between the magnetic poles and the magnetic equator. The oxygen abundance at the magnetic equator is only mildly depleted for θ Aur. It is suggested that the oxygen abundance distribution is consistent with a global field that has a strong quadrupolar component. A detailed comparison is made between the oxygen abundance distribution and that of the distribution of chromium as mapped by Hatzes (1991MNRAS.248..487H). A striking asymmetry is apparent in the contrasting behaviour of the oxygen and chromium abundance pattern at the two magnetic poles.