The first known pulsar was
discovered in August 1967 by student Jocelyn Bell (Belfast, Northern
Ireland, UK, 15 July 1943) and her mentor Professor Antony Hewish
(Fowey, Cornwall, England, UK, 11 May 1924). It had a pulse time of
1.3 seconds. They named the object responsible for this LGM, which
stood for little green men, because it looked like a radio beacon
that extraterrestrial intelligent life emitted. After some
speculation a consensus was reached that the only object that could
be responsible for these signals was a neutron star.
A pulsar (pulsating star)
is a highly magnetized, rotating neutron star that emits a beam of
electromagnetic radiation. This radiation can only be observed when
the beam of emission is pointing towards the Earth, much the way a
lighthouse can only be seen when the light is pointed in the
direction of an observer, and is responsible for the pulsed
appearance of emission. Neutron stars are very dense, and have short,
regular rotational periods. This produces a very precise interval
between pulses that range from roughly milliseconds to seconds for an
individual pulsar.
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| Jocelyn Bell |
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| Antony Hewish |
Video: Jocelyn Bell Burnell (Beautiful Minds, 2010)
Pulsars, Neutron stars and black holes
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