Ever look up at a clear night sky and notice some of the stars blink a bit more than others? They dwindle and fade in and out at different rates, almost making the skies look like sparkling water. What you are looking at most of the time is actual stars that are making their way to the end of their life. The moment prior to their eventual death
But to understand what a Pulsar is you need to Understand what Neutron stars are as well. Neutron stars are one of the possible ends for a star. They result from massive stars which have mass greater than 4 to 8 times that of our Sun. After these stars have finished burning their nuclear fuel, they undergo a supernova explosion. This explosion blows off the outer layers of a star into a beautiful supernova remnant. The central region of the star collapses under gravity. It collapses so much that protons and electrons combine to form neutrons. Hence the name “neutron star”.
Simply put, pulsars are rotating neutron stars. And pulsars appear to pulse because they rotate, Like shown in the figures below & above.
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. In addition, since stars variate in energy output, every single pulsar in the night sky is unique and has it’s own “pulsating” beacon. Kind of the same way species here on Earth have variations of the beating heart.
Information Via: NASA