Neutron stars and green men
In 1967, Northern Irish physicist Jocelyn Bell Burnell discovered a signal that pulsed at a regular rate. The signal, detected by radio telescope, was dubbed the "little green man." It turned out not to be alien communication, but a rapidly spinning neutron star - the first "pulsar" to be detected. In 1974, her supervisor jointly won a Nobel Prize for pulsar work. Bell Burnell was not a recipient.