Earth & Cosmos / Space & Astronomy

Pulsars

Jocelyn Bell Burnell found regularly pulsing radio sources in 1967: spinning neutron stars, the densest stars known.

As a graduate student at Cambridge, Jocelyn Bell Burnell noticed a strangely regular radio signal in autumn 1967 and soon found more; the team announced the discovery in 1968. The sources are rapidly spinning neutron stars, matter packed to nuclear density. In 1974 the binary pulsar of Hulse and Taylor showed an orbital decay that matched Einstein's prediction of gravitational waves, four decades before LIGO.