CIRCULAR ORBITS - A NEW RELATIVISTIC EFFECT IN THE WEAK GRAVITATIONAL-FIELD OF A ROTATING SOURCE

In Schwarzschild spacetime, circular (non-geodesic) orbits with radii < 3M require a larger acceleration pointing outwards (away from the so urce) to remain circular at the same radius when one increases the mod ulus of their angular velocity of revolution. In the Kerr metric this relativistic effect also occurs at arbitrary large distances from the metric source, but only for counter-rotating circular orbits and in a small range of the permitted angular velocities of revolution. Here we discuss a possible way of measuring this effect in the gravitational field of the Earth.