  One of the most luminous explosions detected, gamma-ray bursts, especially
the so-called long-duration bursts, most probably consist of an intrinsic
core-collapse to a black hole inside a super massive star. We point out that
this collapse alone will give a generic gravitational wave burst. It has been
shown that the strength of this burst depends on the dimensionless spin
parameter of the collapsing object. Under descent assumptions the gamma-ray
burst's central engine powers the explosion electromagnetically due to the
rotation of the newly formed black hole. We argue that the peak luminosity and
the isotropic energy of the gamma-ray burst can be associated with the spin of
the black hole, due to this mechanism. Since, both gravitational and
electromagnetic emission depend on the spin, they can be correlated and thus
give a straight estimate for the gravitational wave burst, when we have in hand
a gamma-ray burst with known distance. We discuss detectability limits for
present and future detectors.
