  Even among the brigher cataclysmic variables an appreciable number of objects
exist about which not much is known. One of them, MU Cen, was observed as part
of a small project to better characterize these neglected systems. The temporal
variations of the brightness of MU Cen during quiescence were studied in order
to find clues to the structure of the system and its behaviour on time scales
of hours and shorter. Light curves observed in white light at a time resolution
of a few seconds and with a duration of several hours, obtained in six nights
and spanning a total time base of five months, were investigated using
different time series analysis tools, as well as model fits. The light curve of
MU Cen is dominated by ellipsoidal variations of the secondary star. The
refined orbital period is P(orb) = 0.341883 days. Model fits permit to
constrain the temperature of the secondary star to ~5000 K and the orbital
inclination to 50 deg <= i \<= 65 deg. The latter result permits estimates of
the component masses which are probably somewhat smaller that derived in
previous publications. A second persistent period of P(2) = 0.178692 days was
also identified. Its origin remains unclear. As all cataclysmic variables, MU
Cen exhibits flickering, however, on a rather low level. Its frequency
behaviouris normal for quiescent dwarf novae. There are indications that the
individual flickering events are not always independent but can lead to effects
reminiscent of quasi-periodic oscillations.
