Rapidly Oscillating Ap Stars
A subset of this class of stars, called rapidly oscillating Ap (roAp) stars, exhibit short-timescale, millimagnitude photometric variations and variations in radial velocities of spectral lines. These were first observed in the highly peculiar Ap star HD101065 (Przybylski's star). These stars lie at the bottom of the delta Scuti instability strip, on the main sequence. There are currently 35 known roAp stars. The pulsation periods of these oscillators lie between 5 and 21 minutes. The stars pulsate in high overtone, non-radial, pressure modes.
Read more about this topic: Ap And Bp Stars
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