Distribution of signal-to-noise ratio (SNR) as function of the period. The horizontal black line indicates the adopted threshold (SNR > 2.5) used to select variable star candidates. Histograms in the top and right panels show the marginal distributions of period and SNR, respectively. Additionally, grey dotted lines mark concentrations of periods at specific values, indicating possible instrumental or sampling artefacts such as thermal cycling, scattered light, and satellite observing cadence.