AR Scorpii was first observed in the early 1970s and regular fluctuations in brightness every 3.6 hours led it to be incorrectly classified as a lone variable star. The true source of AR Scorpii’s varying luminosity was revealed thanks to the combined efforts of amateur and professional astronomers. Similar pulsing behavior has been observed before, but from neutron stars — some of the densest celestial objects known in the Universe — rather than white dwarfs.