1994A&A...285..979M

We present non-simultaneous time resolved differential photometry and spectroscopy in the λ5800-7000 A wavelength range of WX Cet in quiescence. From the radial velocities of the Hα emission lines, a most probable orbital period of 79.16 ± 0.04 minutes is derived, but another of 83.81 minutes cannot be completely ruled out. The K semiamplitude of the radial velocity curves constrains the mass ratio to q ≳ 0.11. Large variations in equivalent widths of Hα, He λ5875 A, He λ6678 A and He λ7065 A are not phase dependent. The photometric observations reveal random variability and spikes on time scales T ∼ 0.5 P_orbital. An enhanced emission region 15 % brighter than the disk and located exactly opposite to the hot spot expected by the standard model is consistent with the V/R variations. An empirical relation was found between the mass ratio (q) and the orbital phase of maximal strength of the violet compared to the red peak in the double Hα profile of SU UMa and U Gem subtype dwarf novae. The hot spot region seems to migrate towards the back side of the disk in low q systems. This "hot spot reversed" phenomenon could be explained by a gas stream which passes above the disk and hits its back side or alternatively, by disk thickenings in some resonating locations.