Time evolution of the cavity location (top panel) and eccentricity (bottom panel) for the discs in the Kepler-34 system. The coloured lines represent different Stokes numbers for the dust: blue being Stokes number of 0.1, red being 10⁻², yellow being 10⁻³, and green being 10⁻⁴. The solid black shows the disc where dust was not included. We differentiate between the two dust-to-gas ratios by using solid coloured lines for dust-to-gas ratios of 1, and dotted lines for dust-to-gas ratios of 0.01. The horizontal dashed and dot-dashed line represent the stability limit (Holman & Wiegert 1999) and the observed location of Kepler-34b (Doyle et al. 2011), respectively.