Bell Burnell, (Susan) Jocelyn

née Bell (1943– ) British astronomer: discoverer of first pulsar.

It is probably no coincidence that Jocelyn Bell’s father, a Belfast architect, designed the Armagh Planetarium. She decided, after studying physics at Glasgow, to work for a PhD in radioastronomy with at Cambridge. He had built a large radio-telescope there, with 2048 fixed dipole antennas spread over 18 000 m 2 . Bell checked the recorders daily, examining the 30 m of chart paper, as part of a survey of radio-emitting quasars (remote quasistellar objects) looking in particular for scintillations due to the solar wind. In mid-1967 she saw a small unusual signal, and she found after a few weeks that it recurred. The radio pulsation had a precise period of over a second, and with some effort was shown not to be an equipment malfunction or to be man-made. The name pulsar was coined, and Bell found a second example late in 1967; over 500 are now known.

The explanation due to , and now accepted, is that pulsars are neutron stars, small but very massive stars, rapidly spinning. They form at the end of a star’s life, before its final collapse to a black hole.

Bell Burnell went on to research in astronomy at London and Edinburgh, and a chair at the Open University.