  The collapse of massive stars not only produces observable outbursts across
the entire electromagnetic spectrum but, for Galactic (or near-Galactic)
supernovae, detectable signals for ground-based neutrino and gravitational wave
detectors. Gravitational waves and neutrinos provide the only means to study
the actual engine behind the optical outbursts: the collapsed stellar core.
While the neutrinos are most sensitive to details of the equation of state,
gravitational waves provide a means to study the mass asymmetries in this
central core. We present gravitational wave signals from a series of
3-dimensional core-collapse simulations with asymmetries derived from initial
perturbations caused by pre-collapse convection, core rotation, and low-mode
convection in the explosion engine itself. A Galactic supernovae will allow us
to differentiate these different sources of asymmetry. Combining this signal
with other observations of the supernova, from neutrinos to gamma-rays to the
compact remnant, dramatically increases the predictive power of the
gravitational wave signal. We conclude with a discussion of the gravitational
wave signal arising from collapsars, the leading engine for long-duration
gamma-ray bursts.
