Left: schematic representation of the CIR in the equatorial plane for our default model (see Table 5) at rotational phase 0.0. The observer is located at z → ∞ and y = 0. The star rotates anti-clockwise. The dotted coloured contours represent iso-radial velocity surfaces with values of 1500, 1000, 800, 600, 400, 200, 0, –200, –400, –600, –800, –1000, and –1500 km s^–1 (from left to right). Right: predicted light curve due to electron scattering by the co-rotating CIR with our default model. The black curve yields the results for a Power-2 limb-darkening relation, whilst the red dots correspond to a linear limb darkening.