Gyroscope precession along bound equatorial plane orbits around a Kerr   black hole
  The precession of a test gyroscope along stable bound equatorial plane orbits around a Kerr black hole is analyzed and the precession angular velocity of the gyro's parallel transported spin vector and the increment in precession angle after one orbital period is evaluated. The parallel transported Marck frame which enters this discussion is shown to have an elegant geometrical explanation in terms of the electric and magnetic parts of the Killing-Yano 2-form and a Wigner rotation effect. 
Donato Bini, Andrea Geralico, Robert T. Jantzen
gr-qc