Total intensity (I, bottom panel) and circular polarisation (V, top panel) spectra for all detected CN(2−1) hyperfine components. The spectra are extracted at the position of the strongest emission peak. The figures are labelled with the component rest frequency as determined using line fitting. The 1σ (short dashed) and 3σ (long dashed) limits are indicated. The 1σ limit magnetic field values are indicated in the figure, and we also present the V-spectrum for this field strength in red. Three of the components are so close in frequency that they are presented in a single panel.