## 4. SummaryOf the three possibilities of accounting for the equidistant triplet, the oblique magnetic pulsator model is the least likely one because it would require excessively strong dipolar field or a special field geometry. The true rotational splitting may be the answer but only if were equal to 2. This is because for , the computed is always about two orders of magnitude greater than observed. The true rotational splitting is thus in conflict with the values derived in Sect. 2.4 from the amplitude ratios. For , computed is close to the observed one for very specific model parameters, namely, in the vicinity of point D in Fig. 2. Since point D deviates from the observed position of 12 (DD) Lac by one in and about in , improving the accuracy of and may lead to eliminating the true rotational splitting altogether. The only remaining solution would then involve nonlinear phase lock. This would be bad news for asteroseismology because the nonlinear calculations are much more complicated than the linear ones. © European Southern Observatory (ESO) 1999 Online publication: December 4, 1998 |