O−C diagrams extracted from the Blazhko effect with a mean period (bottom left) using the method described in Section 3.2, and with a period break (bottom right) using the method described in Section 3.4. In the bottom left panel, we see a remaining variation that could be due to an orbit or an intrinsic period change. In the top panel, the blue colour represents the case where no Blazhko effect is extracted.