On gravitomagnetic precession around black holes

We compute exactly the frequency of Lense-Thirring precession for point mas ses in the Kerr metric, for arbitrary black hole mass and specific angular momentum. We show that this frequency, for point masses at or close to the innermost stable orbit, and for holes with moderate to extreme rotation, is less than, but comparable to, the rotation frequency. Thus, if the quasi-p eriodic oscillations (QPOs) observed in the modulation of the X-ray flux fr om some black hole candidates (BHCs) are caused by Lense-Thirring precessio n of orbiting material, we predict that a separate, distinct QPO ought to b e observed in each object.