Upper panel: contour plot of the Herschel/PACS 70 μm image of π¹ Gru over-plotted with an Archimedean spiral. The spiral spacing of 116″ was derived from the wind velocity and the orbital period of the known G0V companion. Lower panel: polar-radial intensity profile of the same image. The position angle is measured north over east and the colour code is given in Jy arcsec^-2. The dashed line shows the same Archimedean spiral as in the upper panel. The (yellow) star illustrates the current position of the G0V companion.