  We discuss a new ringdown frequency mode for vacuum perturbations of the Kerr
black hole. We evolve initial data for the vacuum radial Teukolsky equation
using a near horizon approximation, and find a frequency mode analogous to that
found in a recent study of radiation generated by a plunging particle close to
the Kerr horizon. We discuss our results in the context of that study. We also
explore the utility of this mode by fitting a numerical waveform with a
combination of the usual quasi-normal modes (QNMs) and the new oscillation
frequency.
