Two-pole emission in Grus VI

Abstract

We analyse the recent intensity and circular polarization observations of Grus VI obtained by Cropper et al. and re-examine the light curves obtained previously by Tuohy et al. We show that a viable two-pole model can be constructed in which both cyclotron emission regions are linearly extended. The centroids of the regions are displaced ∼ 30° from the magnetic poles and are separated by ∼ 50° in magnetic longitude in an underlying offset dipolar field distribution. The secondary emission region shows clear evidence for the presence of a low-density tail along which the density declines.