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Jocelyn Bell Burnell

        Science | Astronomers

Bell Burnell, Jocelyn (1943-), a Northern Irish astronomer, discovered the first four pulsars, neutron stars that emit pulses of radiation with a high degree of regularity. Bell Burnell was a graduate student when she made this discovery, which opened up a new branch of astrophysics. The 1974 Nobel Prize in physics was awarded to her thesis adviser, Antony Hewish.

Susan Jocelyn Bell was born in Belfast, Northern Ireland, in 1943. After completing a degree in physics at the University of Glasgow in 1965, Bell moved to Cambridge, England, to pursue a Ph.D. in radio astronomy with Professor Antony Hewish. Radio astronomers study the radio waves emitted by stars and other celestial objects. Bell helped build a new radio telescope and analyzed its recorders' daily output. In October 1967, she noticed what she called a “bit of scruff” in a particular region of the sky. Reviewing the records, she found that the unusual signal reappeared every 23 hours and 56 minutes. Since that is the earth's rotation period with respect to the stars, slightly less than that with respect to the sun, Bell understood that the signal probably originated outside the solar system.

After noting that the signal pulsed every 1.3 seconds, faster than any known natural object, Hewish's team wondered whether it was a communication from LGM (“little green men”) beyond the solar system, but soon dropped that idea. By the end of 1967, Bell had discovered another, even more rapidly pulsating, signal from another part of the sky. Soon Bell discovered an additional two similar signals.

News of the discovery was published in February 1968, and the objects became known as pulsars, a contraction of pulsating stars.

In 1991, Bell Burnell went to the Open University, in Milton Keynes, England, as a full professor of physical science and subsequently was chair of the department. In September 2001, she was appointed Dean of the Science Faculty of the University of Bath.