High-mass evolutionary sequence. sHRD (top panel) with the size of the symbols scaled to the peak-to-peak value of the light curve (between 7.7 and 63.8 mmag). The colour refers to the spectral type, yellow for O and green for B. We include the evolutionary tracks in grey and the instability strips for Z_in = 0.014. For each star marked with a number in the top panel, the LS-periodogram (bottom left panels), and two spectroscopic lines (He Iλ5875 and H_α over multiple epochs bottom right panels) are given. The grey region in the LS-periodogram marks the estimated rotational modulation frequency range (see Sect. 2.3). We show the TESS light curve on the inset of each LS-periodogram (not to scale).