Results of our model (upper left) vs. implementations of ACF (upper right) and GPS (lower) on our test data set. In the left panel, the color represents the model's confidence levels. The sharp drop of samples, seen at 10 days, is a result of the prior distribution of periods (see Table 1). This distribution was also implemented in S. Aigrain et al. (2015) and motivated by the bimodality found by A. McQuillan et al. (2013; 2014).