Geodetic Precession in a Pulsar

Animation of the effect of geodetic precession in the observer pulsar. Two neutron stars orbit one another. The star visible as a pulsar shows rotating beams. The companion is frozen at the frame center. In a flat space-time, where the companion is massless but the pulsar does orbit it for illustrative purpose, the pulsar rotation axis (represented by the arrow) is unchanged after one orbit. Once the companion mass increases to the measured solar mass (about half a million Earth masses, but in a sphere