A pulsar (originally short for ‘pulsating star’) is a rapidly spinning neutron star – the remnant of a supernova explosion. A quasar (from ‘quasi-stellar radio source’) is in fact a distant galaxy with a fluctuating blaze of light and other radiations coming from its central regions. In a pulsar, the poles are even more misaligned, so as the star spins, the magnetic field is swung around in circles. When quasars were first discovered, no one knew what they were. On the photographic plates the objects looked like bright stars.