A rotor dynamics adjustment system (210; 310; 410) comprising: a rotor system (202; 402A, 402B) comprising at least one compressor section (204; 204A, 204B) and at least one turbine section (208; 208A, 208B) operably coupled to a shaft (206; 206A, 206B); one or more rotor system sensors (218; 218A, 218B) configured to collect a plurality of sensor data from the rotor system; an electric motor (212; 212A, 212B) operably coupled to the rotor system; and a controller configured to: monitor the one or more rotor system sensors while the rotor system is rotating; characterize a dynamic motion of the rotor system based on the sensor data from the one or more rotor system sensors; determine a damping correction torque to diminish the dynamic motion of the rotor system; and command the electric motor to apply the damping correction torque to the rotor system, characterised in that the controller is configured to command the electric motor (212; 212A, 212B) to apply one or more torque perturbations to modify the dynamic motion of the rotor system; the electric motor (212; 212A, 212B) is a motor-generator; the controller is configured to operate the electric motor-generator in a generator mode to increase a load on the rotor system (202; 402A, 402B) to apply the damping correction torque to the rotor system; and the controller is configured to operate the electric motor-generator in a motoring mode to decrease the load of the rotor system by driving the electric motor-generator to apply the damping correction torque to the rotor system. a rotor system (202; 402A, 402B) comprising at least one compressor section (204; 204A, 204B) and at least one turbine section (208; 208A, 208B) operably coupled to a shaft (206; 206A, 206B); one or more rotor system sensors (218; 218A, 218B) configured to collect a plurality of sensor data from the rotor system; an electric motor (212; 212A, 212B) operably coupled to the rotor system; and a controller configured to: monitor the one or more rotor system sensors while the rotor system is rotating; characterize a dynamic motion of the rotor system based on the sensor data from the one or more rotor system sensors; determine a damping correction torque to diminish the dynamic motion of the rotor system; and command the electric motor to apply the damping correction torque to the rotor system, monitor the one or more rotor system sensors while the rotor system is rotating; characterize a dynamic motion of the rotor system based on the sensor data from the one or more rotor system sensors; determine a damping correction torque to diminish the dynamic motion of the rotor system; and command the electric motor to apply the damping correction torque to the rotor system, characterised in that the controller is configured to command the electric motor (212; 212A, 212B) to apply one or more torque perturbations to modify the dynamic motion of the rotor system; the electric motor (212; 212A, 212B) is a motor-generator; the controller is configured to operate the electric motor-generator in a generator mode to increase a load on the rotor system (202; 402A, 402B) to apply the damping correction torque to the rotor system; and the controller is configured to operate the electric motor-generator in a motoring mode to decrease the load of the rotor system by driving the electric motor-generator to apply the damping correction torque to the rotor system. <EOS>