An international team of astronomers has discovered eight rare millisecond pulsars hiding inside dense clusters of stars surrounding the Milky Way.

A pulsar is a neutron star — city-sized stellar objects packed with a mass of at least 1.4 times the mass of our sun, which emerge from the explosive deaths of their parent stars — that gives off two beams of radio waves at each pole, due to its strong magnetic field, while also rapidly spinning because of its incredibly large mass. From our perspective, they look like flashing stars, visible only when the beams shine directly at us.