Problems with the Pulsation Mode Selection Mechanism in the Lower Instability Strip (Observations and Theory)



We examine the severe disagreement between the number of predicted and
observed pulsation modes for Delta Scuti stars. The selection of
nonradial modes trapped in the outer envelope is considered on the basis
of kinetic energy arguments. The trapped l=1 modes for the star 4 CVn
are in good, but not perfect agreement with the observations. The
trapping of the l=2 modes is weaker, so that this simple rule of mode
selection may apply to l=1, and possibly not to l=2 modes.

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Available from: Alexey A. Pamyatnykh, Oct 24, 2012
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