What is a Pulsar and What Makes it Pulse?
Simply put, pulsars are rotating neutron stars. And pulsars appear to pulse because they rotate! A diagram of a pulsar, showing its rotation axis and its magnetic axis Pulsars were discovered in late 1967 by graduate student Jocelyn Bell Burnell as radio sources that blink on and off at a constant frequency. Now we observe the brightest ones at almost every wavelength of light. Pulsars are spinning neutron stars that have jets of particles moving almost at the speed of light streaming out above their magnetic poles. These jets produce very powerful beams of light. For a similar reason that “true north” and “magnetic north” are different on Earth, the magnetic and rotational axes of a pulsar are also misaligned. Therefore, the beams of light from the jets sweep around as the pulsar rotates, just as the spotlight in a lighthouse does. Like a ship in the ocean that sees only regular flashes of light, we see pulsars “turn on and off” as the beam sweeps over the Earth. Neutron stars for whi
