Jocelyn Bell discovers pulsars

As a graduate student at Cambridge, Jocelyn Bell was checking miles of chart paper from a radio telescope she had helped to build when she noticed a 'bit of scruff' that repeated precisely every 1.337 seconds. The team led by Antony Hewish jokingly labelled the source LGM-1, for Little Green Men, before more such objects turned up. They proved to be rapidly spinning neutron stars, the collapsed cores of massive stars, that sweep beams of radio waves across space. The discovery was published in February 1968; the 1974 Nobel Prize went to Hewish and Martin Ryle but not to Bell, which caused controversy.

Open on the timeline