  Coalescing binary neutron stars (NS) are expected to be an important source
of gravitational waves (GW) detectable by laser interferometers. We present
here a simple method for determining the compactness ratio M/R of NS based on
the observed deviation of the GW energy spectrum from point-mass behavior at
the end of an inspiral event. Our method is based on the properties of
quasi-equilibrium binary NS sequences and does not require the computation of
the full GW signal h(t). Combined with the measurement of the NS masses from
the GW signal during inspiral, the determination of M/R will allow very strong
constraints to be placed on the equation of state of nuclear matter at high
densities.
