What Is A Pulsar?
A pulsar is a highly magnetized, rotating neutron star or white dwarf, that emits a beam of electromagnetic radiation. This radiation can be observed only when the beam of emission is pointing toward Earth (much like the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission. Neutron stars are very dense, and have short, regular rotational periods. Learn a ton more with this video.