Colour-magnitude diagram of UBC 1 with the intermediate-mass members colour-coded by their number of detected signals. The three rich pulsators are shown in orange. In blue, we show the pulsator with only a handful of independent frequencies in their periodogram, while stars in green have either a single frequency or noisy Fourier spectra and can therefore not be identified as pulsators unambiguously. For stars with (G_BP − G_RP)₀ > 0.5, rotational modulation (purple) is the only source of variability. Black symbols indicate stars without a light curve. Stars shown as crosses are potential binaries. The dotted lines indicate the approximate edges of the γ Dor instability strip from Dupret et al. (2005) and the dashed line denotes the red edge of the empirical δ Sct instability strip from Murphy et al. (2019). Details on individual stars (labelled with their ID number) can be found in the text.