A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2020; you can also visit the original URL.
The file type is
Twelve cool Ap stars are known at present to undergo rapid light oscillations at low amplitude (ΔB < 0m.012) and with periods of minutes. These rapidly oscillating Ap (roAp) stars also exhibit amplitude modulation with timescales of days, which correspond to the magnetic/rotation periods (when those have been measured). In at least one case (HR 3831), 180° phase shifts in the dominant oscillation are seen twice per modulation cycle.doi:10.1017/s0074180900158188 fatcat:fckn6gti5rff7hpininb2gpf7y