2020MNRAS.494..958N

We investigate the short-term optical variability of two γ Cas analogues, πAqr and BZ Cru, thanks to intensive ground-based spectroscopic and space-borne photometric monitorings. For both stars, low-amplitude (mmag) coherent photometric variability is detected. The associated signals display long-term amplitude variations, as in other Be stars. However, these signals appear at high frequencies, especially in πAqr, indicating p modes with a high degree l, a quite unusual feature amongst Be stars. While BZ Cru presents only low-level spectral variability, without clear periodicity, this is not the case of πAqr. In this star, the dominant photometric frequencies, near ∼12 d^–1, are confirmed spectroscopically in separate monitorings taken during very different disc activity levels; the spectroscopic analysis suggests a probable tesseral nature for the mode.