Contact binary before separation (top) and after separation (bottom). Top: Configuration of the contact binary the moment of fission where the gravitational force F_G and the centrifugal force F_C are equal. The cross indicates the center of mass of the system. The long and short semiaxes (a and c) are aligned with the body-fixed x- and z-axes of the respective bodies. Bottom: Angular velocities of the bodies after the contact binary separates.