Up: Multi-period pulsation and amplitude Cephei
Recent observations confirm the two-frequencies solution for DQ Cephei, and
the observations indicating the two pulsation modes
show possible regular amplitude variations with a period exceeding 46 years. The
amplitude variations seem to indicate energy conservation. The modulation period of
the amplitude variations is too long to be explained by beat modulation of rotating
split, and the position of DQ Cephei on HR diagram does not agree well with the
hypothesis that the modulation of amplitude variation is
caused by the overlap of different modes. So an interpretation in terms of two or more
close frequencies can be ruled out.
We suggest that the amplitude variation is caused by some kind of intrinsic amplitude
variability, such as a slow transfer of pulsation energy between different modes.
Acknowledgements
This work has been supported by the
Chinese National Natural Science Foundation
Up: Multi-period pulsation and amplitude Cephei
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