Science history: Jocelyn Bell Burnell discovers a signal of ‘little green men,’ but her adviser gets the Nobel Prize — Nov. 28, 1967
QUICK FACTS
Milestone: Radio pulsars discovered
Date: November 28, 1967
Or: University of Cambridge, United Kingdom
WHO: Jocelyne Bell Burnell
An astronomy graduate student in England was browsing more than 100 pages of data a day from a radio telescope when she noticed a strange, repetitive signal that she dubbed “LGM” – short for “little green men.”
Bell Burnell was solely responsible for operating the observatory and analyzing the data, and for weeks the graduate student had seen a strange “a little skin” in a sea of radio data from the observatory.
“From a particular part of the sky, an unclassifiable signal would sometimes come back and my brain would start saying, ‘You’ve seen something like this before, haven’t you? You’ve seen something like this before.’ from this piece of skyright?” she said during the question-and-answer session.
She nicknamed the recurring signal “little green men” because it was what she called an unclassifiable signal that was not related to an obvious source of interference, such as car noise or problems in the wiring.
She pulled up past recordings and noticed the same signal, which she passed on to her advisor, Antony Hewish. Hewish noted that the squiggle was only one part out of 10 million of the data and suggested that she needed a faster recorder.
For a month, she heard nothing. Then, on November 28, she found a series of pulses spaced 1.3 seconds apart. She informed Hewish, but when he came to observe on another telescope, nothing happened.
“It was a horrible moment,” Bell Burnell said. “And suddenly there it was, five minutes later, because we had miscalculated when the telescope would see it.”
The duo tried to figure out where it was coming from. It did not come from ordinary sources of interference and it was too fast to come from a known type of star.
Then Bell Burnell noticed another patch of skin with a signal repeating regularly from another part of the sky. In total, over the next month, they found four such signals. Hewish, Bell Burnell and their colleagues submitted their discovery to the journal Nature. Shortly afterward, Hewish gave a lecture at Cambridge about the discovery, which sparked a media frenzy over the possibility of extraterrestrials.
This media attention was accompanied by a heavy dose of stupidity and sexism.
“Journalists asked pertinent questions: Was I taller or not as tall as Princess Margaret, and how many boyfriends did I have at one time?” Bell Burnell recalled.
Bell Burnell and Hewish quickly ruled out the presence of extraterrestrials, and by the following year, scientists had discovered dozens of these strange cosmic repeaters.
In May 1968, astrophysicist Thomas Gold demonstrated that mysterious signals came from pulsars — rapidly rotating neutron stars that, like cosmic beacons, constantly sweep beams of radio waves across the cosmos. (Neutron stars are ultradense, collapsed cores of stars that have gone supernova.)
Pulsars send out regular beams of radiation because their powerful magnetic fields are misaligned with the rotation axes of the remaining star envelopes, according to the American Physical Society.
In 1974, Hewish shared the Nobel Prize in Physics for his discovery of pulsars with Martin Ryle, one of the main creators of the radio telescope. Bell Burnell was snubbed, prompting some to dub the awards the “No-Bell Awards.”
Bell Burnell, for his part, took the snub philosophically. She noted that it was still a matter of debate whether an advisor or mentee would get credit for their research, and believed that the Nobel should not be awarded to students except in rare cases.
“I’m not upset about it myself – after all, I’m in good company, aren’t I?” she joked that she didn’t receive the award.
Bell Burnell later left radio astronomy to work in x-ray and gamma-ray astronomy. But his legacy was ultimately honored. In 2018 she received the award A $3 million Breakthrough Prize for his role in the discovery of pulsars. She donated his earnings to finance a scholarship.
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