  We compute the emission of gravitational radiation from the merging of a
close white dwarf binary system. This is done for a wide range of masses and
compositions of the white dwarfs, ranging from mergers involving two He white
dwarfs, mergers in which two CO white dwarfs coalesce to mergers in which a
massive ONe white dwarf is involved. In doing so we follow the evolution of
binary system using a Smoothed Particle Hydrodynamics code. Even though the
coalescence process of the white dwarfs involves considerable masses, moving at
relatively high velocities with a high degree of asymmetry we find that the
signature of the merger is not very strong. In fact, the most prominent feature
of the coalescence is that in a relatively small time scale (of the order of
the period of the last stable orbit, typically a few minutes) the sources stop
emitting gravitational waves. We also discuss the possible implications of our
calculations for the detection of the coalescence within the framework of
future space-borne interferometers like LISA.
