Illustration of fp computation for K2 stars, all inclinations, ΔT_spot2,PHZ_in, representing power (frequential analysis, upper panel) and fitted mass (temporal analysis, lower panel) vs. rms of for no planet (black) and with an injected planet (orange, 1 M_Earth). The green line corresponds to a constant fp level of 1%, and the red line shows a fp level depending on the rms of . The green and red dots show the upper and lower bounds corresponding to the criterion (see text).