FT for J2102-4145, for SOAR, ULTRACAM u_s, g_s, i_s, r_s, and SMARTS-1m observations. The 1/1000 FAP detection limit (red dashed line) was computed using random shuffling of the data. The spectral window for each case is depicted as an inset plot, with the x-axis in μHz and all inset plots being in the same scale. For the r_s ULTRACAM data, the combination (f₁ + f₂)/2 of the periods of 1.61 h (171.872 μHz) and 1.01 hr (274.345 μHz) its half of the orbital period.