The reality of the previously reported triple-wave light curve (Cuypers et al. 1989, A&A Suppl. 81, 151), and relations between rapid line profile and brightness variations of the B1-2III-Ve star η Cen (HD 127972) were investigated by means of simultaneous high-resolution spectroscopy (4 nights, 86 Si III 455.2622 nm profiles) and two-station uvby photometry (14 nights) secured in 1992. To this database were added the uvby photometry by Cuypers et al. and unpublished b observations by L.A.B. from 1988–1991.