  We report a simultaneous ground and space-based photometric study of the Beta
Cephei star Nu Eridani. Half a year of observations have been obtained by four
of the five satellites constituting BRITE-Constellation, supplemented with
ground-based photoelectric photometry. We show that carefully combining the two
data sets virtually eliminates the aliasing problem that often hampers
time-series analyses. We detect 40 periodic signals intrinsic to the star in
the light curves. Despite a lower detection limit we do not recover all the
pressure and mixed modes previously reported in the literature, but we newly
detect six additional gravity modes. This behaviour is a consequence of
temporal changes in the pulsation amplitudes that we also detected for some of
the p modes. We point out that the dependence of theoretically predicted
pulsation amplitude on wavelength is steeper in visual passbands than those
observationally measured, to the extent that the three dominant pulsation modes
of Nu Eridani would be incorrectly identified using data in optical filters
only. We discuss possible reasons for this discrepancy.
