Upper limit f_max for the occurrence rate of planets around hot subdwarfs from our sample of 549 stars without a detection, considering they have a G magnitude between 13 and 13.5. The two panels share the same axes with the period (in days) in abscissa and radius of the orbiting body (in R_⊕) in ordinate. We focus here on short-period planets (1 to 6 days) of few Earth radii (0.5–3). Top panel: recovery rate P_detection (deep blue = 0, yellow = 1). Bottom panel: upper limit for the occurrence rate f_max (deep blue = 0, yellow = 1). For this graph, the confidence level was set to 0.95. For readability, the value of the limit is also written in each cell.