fits show that the long cycle decreases its period and amplitude during the time baseline (Fig.7). It is clear from this figure the continuous smooth decrease of the brightness of the primary eclipse (lower red and blue points, orbital phases around 0 or 1) along with the much fainter secondary eclipses occurring at some epochs (green very low points, orbital phases around 0.5). It is also clear how the secondary eclipse becomes brighter as time goes by.

We analyzed the orbital light curves after removing the long cycle. This was done using the residuals of the fits shown in Fig.7. Examples of “cleaned” orbital light curves are shown in Fig.8. These show changes in the shape of the orbital light curve which are more evident during the first observing epochs (Fig.9). In particular, we notice the changes in the shape of the eclipses and the ingress and egress light curve branches. The primary eclipse is not always deeper than the secondary one, this is specially evident in the first observing epochs. We also notice changes in the shape of the light curve during epochs of long cycle maximum and minimum (Fig.10); during the minima of the long cycle occurs the 