1999MNRAS.305..473L

We argue that quiescent WZ Sge is a rapidly spinning magnetic rotator in which most of the matter transferred from the secondary is ejected from the system. Assuming that the observed 27.87-s oscillation period results from the spinning white dwarf, we propose that the other observed principal period of 28.96 s is a beat caused by reprocessing of the rotating white dwarf beam on plasma blobs in Keplerian rotation at the outer disc rim. The weaker, transient, 29.69-s period is identified as a beat with the Keplerian period of the magnetosphere. WZ Sge evolves through a cycle of spin-up and spin-down phases. During the spin-down phase it is a DQ Her star; during the spin-up phase it should be a ER UMa star.