Polarised moving radio bursts and open magnetic field regions. Radio contours and extrapolated open magnetic field lines are overlaid on AIA 211 Å images at 13:50 UT. The positive open field lines (blue) and left-handed circularly polarised burst (blue contours) are located to the right of the active region where the CME originates, while the negative open field lines (red) and right-handed circularly polarised burst (red contours) are located to the left of the active region. The sense of polarisation is from the point of view of the observer. The two radio sources have an opposite sense of circular polarisation since they propagate on either sides of the active region, through open field regions also of opposite polarity.