Corner plot of the posterior samples of the joint 1P+GP model for HIP 64283. The mode of each parameter, marked as the continuous, red line, was adopted as the best fitting parameter in Table 4. The red dashed lines mark the interval that contains 68% of the posterior samples. We note that the posteriors of the planet model are well constrained, while the posteriors of the GP model (especially the factor C) are relatively broad and thus allow for a wide range of models.