the derived rotation frequency $f_{\rm rot}$, while the dotted line indicates the solitary high-amplitude mode which was found.](KIC7365537_single.pdf){width="88mm"}

There are several stars for which a single high-amplitude mode was detected, which does not belong to a period spacing series and which differs from the rotation frequency. In Fig.\[fig:single\] we show the frequency spectrum of KIC7365537 as an example. For these modes the identification in Table \[tab:param\] is marked “S”. Because our method can not be applied to these single modes, we again use the values of $f_{\rm rot}$ and $\Delta\Pi_l$ which were derived from the prograde series in the same star, in the subsequent analysis. The selection of series of modes in some stars versus the presence of single modes in others also tells us a great deal about their respective stellar structure. It has been suggested by @Dziembowski1991 that such single high-amplitude modes could occur due to mode trapping effects. However, detailed theoretical modelling of each of these individual stars is required to confirm this.

![image](sample_cor_ext2.pdf){width="\textwidth"}

![image](spinpar_ext.pdf){width="\textwidth"}

Fig.\[fig:sample\_ov\] illustrates the frequency $f_{\rm dom,corot}$ of the dominant mode of each detected series in the corotating frame with respect to the computed rotation frequency. An alternative version of Fig.\[fig:sample\_ov\] in the 