Evolution of the SOT/BFI G-band normalised mean intensity of the orphan penumbrae displayed in Fig. 6. The dots are the individual measurements for each image and the thick solid line represents a 3 h smoothing of these measurements. The continuous thin solid line indicates a 3 h smoothing of normalised mean intensity measurements of sunspot penumbra. The vertical dashed line marks the time of the overlying Hα filament’s disappearance.