P_rot as a function of P_orb for the 88 non-transiting-exoplanet candidate systems. The size of the dots is a function of the Kepler apparent magnitude of the host star, sourced from Brown et al. (2011), whereas the temperature T_eff, sourced from Berger et al. (2020), is colour-coded. The grey sample consists of 576 confirmed single-planet-host main-sequence solar-like stars with a rotation period obtained by García et al. (2023). KIC 5697777 is represented by a diamond. The dashed black line corresponds to the fit of the lower envelope of points obtained by McQuillan et al. (2013).