Astronomers identify pulsars as rapidly rotating, highly magnetized, extremely dense distant stars that emit beams of electromagnetic radiation in the form of x-rays or radio waves, seen here on Earth as visible bursts or pulses of energy. Stellar investigators can observe these blips from a pulsar only when the star's rotation perfectly aligns the beam of radiation with Earth side telescopes. Depending on the speed of rotation, the pulse may repeat, or reappear, in a matter of seconds or even microseconds. The radiation bursts from some pulsars come with such a precise repetition that the timing accuracy compares favorably with the reliability of an atomic clock.
Though pulsars have existed throughout the universe for eons, the first difinitive observation of one did not occur until 1967 by British astrophysicist Jocelyn Bell Burnell and radio astronomer Antony Hewish. At first thinking the strange, cyclical emanations might provide verifiable evidence of communication broadcast by an outer space civilization, they called the star LGM-1, the LGM standing for "Little Green Men." It only took the discovery of a second pulsar to put an unfortunate finish to this theory. As of today, astronomers have identified and examined over 1,500 pulsars.
The consensus thought among astronomers holds that pulsars originate in the aftermath of the dramatic expiration of a super sized star. At death the star literally explodes. The explosion strips the supernova of all but its dense inner core. The intensity of the core's gravitation crushes this new entity into a neutron star.
Not all neutron stars become pulsars, however. It requires certain specific circumstances to occur in order for a pulsar to develop. For one thing, the rotation speed of a neutron star needs to increase to an almost unbelievable velocity.
Following a supernova detonation, the dense inner core, the neutron, may become a roving globe having an extremely high level of gravitation. Should this new star become closely associated with a normal star, with one orbiting around the other, the neutron will begin to absorb material from its companion through the overpowering strength of its gravitation.
This produces the condition needed to magnify the rotation speed of the neutron and turn it into a pulsar. The material extracted from the neutron's companion star rains down continuously upon the neutron in a manner to increase its rate of spin. After a few million years of this activity, the neutron blossoms into a radiation emitting, rapidly rotating pulsar.