Rotating frame of reference
A Rotating frame of reference is not an inertial frame of reference because a rotation is an acceleration, by definition.
Possible applications
Some Gamma ray burster observations are detecting x-ray and gamma ray jets which may be due to rapidly rotating neutron stars. It is not yet understood how these potentially large bodies could be rotating rapidly enough to emit x-rays; thus the physical processes involved require further characterization.
See Also
Black holes, Celestial mechanics, Gravitational physics, Mechanics, Newton's Laws of Motion, Rigid body dynamics, Unsolved problems in physics