  The luminosity gap between novae (M_R < -10) and supernovae (M_R > -14) is
well known since the pioneering research of Zwicky and Hubble. Nearby galaxy
clusters and concentrations offer an excellent opportunity to search for
explosions brighter than classical novae and fainter than supernovae. Here, we
present the results of a B-band survey of 23 member galaxies of the Fornax
cluster, performed at the Las Campanas 2.5-m Irene duPont telescope.
Observations with a cadence of 32 minutes discovered no genuine fast transient
to a limiting absolute magnitude of M_B=-9.3 mag. We provide a detailed
assessment of the transient detection efficiency and the resulting upper limits
on the event rate as function of peak magnitude. Further, we discuss the
discoveries of five previously unknown foreground variables which we identified
as two flare stars, two W Uma type eclipsing binaries and a candidate delta
Scuti/SX Phe star.
