General relativity reveals pulsar beams Pulsars are rotating neutron stars that emit beams of radio waves along their magnetic poles, seen as regular pulses if the beam points toward Earth. Desvignes et al. monitored a pulsar for more than a decade, observing how its radio pulses vary. General relativity causes precession of the rotation axis, because of the influence of a binary companion. In 2005, two pulses per rotation were visible, one from each magnetic pole, but by 2018 one had precessed out of our line of sight and disappeared. Mapping the radio emission across the magnetic pole determines the beaming angle, the angular region in which a radio observer can detect a pulsar. Science , this issue p. 1013