Lomb-Scargle periodogram of the timing residuals for the solution of Table 1. The periodogram is sampled at f_m/5 where f_m ≃ 2268 days⁻¹ is the inverse of the full time span. From left to right vertical lines show the frequencies of the red-noise component (f_RN ≃ 1650 day⁻¹, black), the Earth orbital period (f_E, green), the outer-orbit orbital period (f_O, orange), the inner-binary orbital period (f_I, red) and the SEP violation signature (2f_I − f_O, purple).