Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pulsars are highly magnetized, rotating neutron stars that emit beams of electromagnetic radiation. This radiation can only be observed when the beam of emission is pointing towards the Earth, much the way a lighthouse can only be seen when the light is pointed in the direction of an observer, and is responsible for the pulsed appearance of emission. The precise periods of pulsars makes them useful tools - observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. Learn more about pulsars, their origin and scientific significance in the following pages.