Example of how we calculated the SD ratio of the zero-mass moon model, here for the case of KOI-1925.01. The histogram is calculated from the marginalized posterior distribution, and this is generalized to a continuous function using KDE (red line). We then evaluated the density in the limit of zero mass and compare it to that of the prior. For example, here we find a 20:1 Bayes factor in favor of a zero-mass moon model.