The marginalized and joint posterior PDFs of the model parameters from Model 1 of the observed RVs. Model 1 of the observed RVs models the two planets with Keplerian orbital solutions and the residual RV activity signal with a GP regression model trained on the K2 photometry in Fig. 1. Kernel density estimations of the trained posteriors are shown in the histograms of the logarithmic GP hyperparameters λ,Γ, and P_GP (Cols. 2–4).