Central region of the F850LP HST image after unsharp masking. The 10′′ ring is clearly visible, as well as another elongated, disc-like structure with semi-major axis of ≈3.2′′ and semi-minor axis of ≈1.4′′, as delineated by the red ellipse. It has a width of about 2′′. The structures seen at the very centre of the galaxy in the bottom panel of Fig. 7 (within ≈0.8′′) are within the elongated dark blob at the centre of this figure.