Time series for, from top to bottom: a) the HARPS RVs of K2-3; b) ΔRV (Sect. 2.3); c) the RVs corrected from the αΔRV of the maximum likelihood model together with the dynamical model (the solid black line represents the median model, and the shades of grey represent the 68.3, 95.5, and 99.7% Bayesian confidence intervals); and d) the RV residual from the maximum likelihood dynamical model.