A subgroup of Beta Cephei stars in which non-radial pulsation is particularly significant. In this group, multiple periods (0.15–2 days) are often present, but all tend to be highly unstable. The type star, 53 Per (also known as V469 Per), has a range of 4.81–4.86 mag. and a period of 0.304 days.
Subjects: Astronomy and Astrophysics.