  The time evolution of a set of 22 Mo unstable charged stars that collapse is
computed integrating the Einstein-Maxwell equations. The model simulate the
collapse of an spherical star that had exhausted its nuclear fuel and have or
acquires a net electric charge in its core while collapsing. When the charge to
mass ratio is Q/M >= 1 the star do not collapse and spreads. On the other hand,
it is observed a different physical behavior with a charge to mass ratio 1 > Q/
M > 0.1. In this case, the collapsing matter forms a bubble enclosing a lower
density core. We discuss an immediate astrophysical consequence of these
results that is a more efficient neutrino trapping during the stellar collapse
and an alternative mechanism for powerful supernova explosions. The outer
space-time of the star is the Reissner-Nordstrom solution that match smoothly
with our interior numerical solution, thus the collapsing models forms
Reissner-Nordstrom black holes.
