L′-band observations and the combined observations. Left panels: reconstructed images. Middle panels: computed significance map. Right panels: squared visibilities. First row: 2012-01-10. Second row: 2012-12-18. Third row: 2013-11-16. We interpret thestructures seen in all three epochs as caused by an illuminated disc rim. The colour bars in the reconstructed images indicate the flux contained in each pixel as a fraction of the peak flux in the image after subtracting the central source. The colour bars in the significance maps represent significance of the binary fit to the data at each pixel location (σ).