SIMBAD references

We present calculations indicating the possibility of a new class of Type I supernovae. In this new paradigm, relativistic terms enhance the self-gravity of a carbon-oxygen white dwarf as it passes or orbits near a black hole. This relativistic compression can cause the central density to exceed the threshold for pycnonuclear reactions so that a thermonuclear runaway ensues. We consider three possible environments: (1) white dwarfs orbiting a low-mass (∼10-20 M_☉) black hole, (2) white dwarfs encountering a massive [~(1-3)x10³ M_☉] black hole in a dense globular cluster, and (3) white dwarfs passing a supermassive (∼10⁶-10⁹ M_☉) black hole in a dense galactic core. We estimate the rate at which such events could occur out to a redshift z~1. Event rates are estimated to be significantly less than the rate of normal Type Ia supernovae for all three classes. Nevertheless, such events may be frequent enough to warrant a search for this new class of supernova. We propose several observable signatures that might be used to identify this type of event and speculate that such an event might have produced the observed ``mixed-morphology'' Sgr A East supernova remnant in the Galactic core.