  As it was proposed and recently verified experimentally, the mechanism of
Feshbach resonance in a condensate can create a second condensate component of
molecules that coexists with the atomic condensate. In this work we investigate
signatures of the presence of the molecular condensate through the equilibrium
properties and collective excitations of the hybrid system of atoms and
molecules, subjected to a trap, employing a time-dependent variational ansatz.
We show that the shape of the condensate changes significantly by the presence
of the molecules and that modes unique to this hybrid system appear at
observable frequencies.
