Periodograms of residuals after fitting the double eclipsing binary model. We show separately ground-based data (left) and TESS short-cadence data (right). The two gray horizontal lines in both panels indicate false alarm probability levels of 0.1 (lower) and 0.01 (upper). Right panel: additionally identification of some of the most prominent modes and their harmonics. Here, the frequency is defined as f = 1/P. The orange vertical lines in the right panel indicate the pseudo-synchronous rotation frequency and its main harmonics that correspond to the eccentricity found in the best double eclipsing binary model (solid) and f_psrot increased by 1% relative to Eq. (9) (dashed).