Pulsars are rapidly spinning neutron stars with powerful magnetic fields. They spin up to 30 times per second, are of the order of 10 miles across, and have magnetic fields probably shaped like a bar magnet, but with a strength of a trillion gauss of or more. By comparison, the Sun's magnetic field is about 1-2 gauss, sunspot fields are about 1000 gauss. These magnetic fields, moving rapidly through space, can accelerate charged particles to nearly the speed of light if there happens to be any material in their vicinity. They can also, it seems, emit charged particles like protons and electrons from their surfaces as the neutrons there decay into these end products. In either instance, the charged particles produce electromagnetic radiation called 'synchrotron radiation' named after the light often seen in man-made particle accelerators here on Earth.
The pulses may occur as alternately one of or the other of the poles of the spinning neutron star pass across our line of sight. Pulsars are highly directional, which means there could well be LOTS of them out there spinning furiously, but unless the viewing geometry is right, we would see no pulses, just a very hot neutron star glowing perhaps as a bright X-ray object.
Copyright 1997 Dr. Sten Odenwald
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