tangentially infalling material , hence we have assumed critical rotation for this star. We find that our model is practically the same for synchronous and critical gainer.

We use the q-search method, usually applied to over-contact or semi-detached binaries when no spectroscopic data are available . We find convergent solutions for a range of mass ratios $q= M_{c}/M_{h}$, where the subindexes “c” and “h” refer to the cool and hot stars. A fit with a fourth order polynomial to the corresponding $\Sigma$ $(O-C)^{2}$ values, yields an optimal mass ratio $q$ = 0.22 (Fig.13). Previous studies show $\overline{q}$ = 0.23 $\pm$ 0.05 (standard deviation) for the few studied DPVs [@Mennickent2016]. For the q-search we used data obtained at maximum (Fig.10 upper), when the disk influence should be lower, as discussed in the previous section.

Next we model the light curve at data ranges representative of the maximum and minimum of the long cycle. We choose those data ranges that best represent the observed differences between maximum and minimum, where the inversion of the eclipses is more evident. The parameters of the fits are shown in Table2 and a comparison of our theoretical models and observations is given in Fig.14. While the 