Pulsars are objects in space that send out frequent burst of electromagnetic radiation, mainly in the form of radio waves or gamma rays. Pulsars receive their name from these pulses. Pulsars are rapidly spinning neutron stars (see Neutron star) which are surrounded by an extremely powerful magnetic field which surrounds the star and rotates with it. This magnetic field creates a strong electric field that tears electrons and protons from the star's surface. As these particles flow from the star, they emit energy in the form of radio waves or gamma waves. With a giant radio telescope, an astronomer can detect a pulse of radio waves each time the pulsar rotates and the beam sweeps past the earth.
Pulsars rotate at the rate of twice a second. They eventually lose energy and slow down. They do this in such a gradual and predictable manner that their pulses can be used to tell time.
Anthony Hewish and Jocelyn Bell, British astronomers, at Cambridge University discovered the space phenomena in 1967. Today, scientist study pulsars to learn more about the motions at the center of globular clusters, the matter between stars in the Milky Way, and other topics as well. Also, they still continue to investigate on how pulsars turn their enormous rotational energy into radio beams.
Check out the diagram of a pulsar