  We present the results of simultaneous spectroscopic and photometric
observations of the cataclysmic variable star (hereafter CVs) V455 Andromedae,
belonging to the WZ Sge sub-class, in quiescence. Using the spectroscopic data
we computed time-resolved Doppler tomograms of the system demonstrating its
behavior at different orbital phases. In the tomograms one can see the periodic
brightening of different regions within one orbital cycle. We interpret this
brightening as being due to the interaction of four phase-locked shock waves in
the disk with a specific internal precessing density wave that develops inside
the disk, because of the tidal influence of the secondary star, and this
density wave propagates up to the disk's outer regions. When the outer part of
the density wave in its precessional motion reaches a shock wave the local
density grows, which amplifies the shock (by increasing $\rho V^{2}/2$). This
results in an additional energy release in the shock and can be observed as a
brightening. Analysis of the tomographic results and the photometric data shows
that two main sources contribute to the light curves of the system: the
radiation of the "hot line" and the bow-shock gives us two major orbital humps,
located approximately at the orbital phases $\phi=0.25$ and $\phi=0.75$; the
amplification of the four shock waves may give us up to four "superhumps"
shifting over the light curve with the precessional period. These two effects,
when overlapping, change the shape of the light curves, shift the hump maxima,
and they sometimes produce more than two humps in the light curve. We should
emphasize that when saying "superhumps" we imply an effect that is observed in
quiescent light curves of WZ Sge stars, as opposed to "classical" superhumps
usually observed in outbursts.
