Neutron star
Neutron stars were thought to be too faint to be detectable. Little work was done on them until November 1967, when Franco Pacini (1939–2012) pointed out that if the neutron stars were spinning and had large magnetic fields, then electromagnetic waves would be emitted. Radio astronomer Antony Hewish and his research assistant Jocelyn Bell at Cambridge soon detected radio pulses from stars that are now  known as pulsars.