FIP periodogram of HD 13808: − log₁₀ FIP (in blue) and log₁₀ TIP (in yellow) of the presence of a planet in a centred frequency interval [ω − Δω, ω + Δω] as a functionof ω. Here, Δω = 2π∕T_obs, where T_obs is the total observation time span. Different colours correspond to independent computations with POLYCHORD. The plot inside the black box represents a zoom-in on the region close to 18.9 days.