Bell was a graduate student in 1967 when she and her doctoral advisor Antony Hewish constructed a low frequency radio array to study the effect of the solar wind on nearby radio sources.

During the commissioning phase of their array, while analyzing long readouts of data by hand, Bell discovered a regular signal with a very stable period of about 1.33s.

Bell and Hewish quickly ruled out a problem with the instrument or human-made interference as explanations.

Imagine seeing that remarkably regular signal and not knowing of an astrophysical source that might explain it.

They jokingly nicknamed it LGM-1, for "Little Green Men."

Here is a transcript of Jocelyn Bell Burnell's after-dinner speech at the Eighth Texas Symposium on Relativistic Astrophysics, recounting the discovery.

http://www.bigear.org/vol1no1/burnell.htm

The sources were soon identified as rotating, magnetized neutron stars. A tightly collimated beam of radiation is ejected along the neutron star's magnetic axis. We see regular pulses as it rotates, hence the name "pulsar."

The discovery of pulsars provided an extraordinary new laboratory for physics. For example, a gradual decay in the orbit of the pulsar-neutron star binary PSR B1913+16 matches the prediction of general relativity, with energy lost via gravitational waves.

Image: NASA

Antony Hewish received the Nobel Prize in 1974 for his "decisive role in the discovery of pulsars." In a move that can only be described as gratuitous sexism, the Nobel Committee decided not to include Jocelyn Bell Burnell on the prize.

A younger graduate student (Brian Josephson) had received a share of the prize the previous year, so it's not like there was a prohibition against awarding students.

But that's not all. It gets worse.