Pulsar and Companion Star (video) CSIRO Australia Share Print E-Mail Loading video... Caption The aging pulsar rotates slower and slower, then matter from its companion spins it up again. As the pulsar is spun up, it alternates between emitting X-rays (white) and radio waves (pink). Credit ESA Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.