Comparison between HST Hα (left) and NIR (right) images of Hb 12. The intensities shown in the left and right panels are on logarithmic and linear grey scales, respectively. North is up and east is to left. Left: faint arc-like filament is visible in the northern part of the nebula. This arc might be the optical counterpart of the northern part of the eye-shaped structure seen in the right panel. In the inset of this image, a series of rings aligned with bipolar lobes are visible. The central cross of this nebula is a diffractionartefact as the core is saturated. Right: several morphological structures are labelled in the F175W image. These threebipolar lobes are labelled ‘ionised lobe’, ‘secondary lobe’, and ‘primary lobe’. An eye-shaped structure is visible in the equatorial region of Hb 12.