Forgotten Women in Science: Jocelyn Bell Burnell (July 15, 1943- )
A star is a combination of gases, usually hydrogen and helium, held together by gravity. Their central core is very hot, and it produces energy. Some of this energy is released as visible light, which is what allows us to observe stars from the Earth. However, stars do not burn on indefinitely. What happens when massive stars, stars multiple times larger than the mass of the sun, explode and die? If you have heard of a “supernova”, you might be somewhat familiar with the collapse of a dying star. The term ‘supernova’ tends to be associated with a catastrophic event where stars implode and form a black hole, leaving no other star-like remnants. To be fair, this can certainly happen on occasion. However, we now know that giant stars may not completely disappear when they die—instead, they can leave behind extremely dense, rotating, neutron stars in their place. These neutron stars are detectable because they release small bursts of electromagnetic radiation called “pulsars”.
Pulsars are an extra-terrestrial source of radiation that are most often detected in the radio region of the electromagnetic spectrum (see photo below). Radio pulsars are highly-magnetized and emit a light-house beam of radiation that produces a pulsed emission. These emissions can only be detected when the beam is pointed toward the earth, similarly to the way we can only see the light from a lighthouse when it is pointed at us. Most pulsars rotate once per second, but some can rotate as many as 700 times per second. Pulsars rotate with periodicity, thus, they can be used for very accurate timekeeping. Although slower-rotating pulsars are not as precise as atomic clocks, the faster pulsars are actually more precise than atomic clocks—which are considered to be the most accurate way to measure time and frequency.
Although neutron stars and pulsars are a foreign concept to laypeople, they have multiple uses for astronomers and astrophysicists. For instance, a neutron star is the only place where the behavior of matter at nuclear density can be evaluated. They also allow for tests of general relativity in an intense gravitational field. Pulsars from neutron stars can be used for mapping, and one could theoretically create a navigational system based on pulsar positioning. Finally, as mentioned earlier, pulsars can also be used as a precise clock. One pulsar, J0437-4715 has a period of 0.005757451936712637 seconds, with an error rate of only 0.000000000000000017 seconds (i.e., a VERY small amount of error).
The first pulsar emitted by a neutron star was detected in 1967 by a female graduate student, Jocelyn Bell Burnell. Before this time, astronomers were totally unaware of the existence of neutron stars. Bell Burnell detected what she called “scruff” on chart-recorder papers obtained from a radio telescope that she herself helped assemble. In fact, Bell Burnell analyzed three miles worth of chart recordings in order to identify the existence of this “scruff”. Initially, she nicknamed these signals “LGM”, little green men, as if the ‘noise’ were the result of extraterrestrial life (no one, herself included, really took this idea seriously). However, she soon learned that these signals, or flashes, coming from deep space were the result of emissions from a new type of star, which would come to be known as a neutron star. This discovery was noted as one of the most remarkable of the 20th century and the finding changed scientists’ view and understanding of the universe. In 1974, the Nobel Prize for this work went to Anthony Hewish, Bell Burnell’s PhD advisor, and Martin Ryle, a fellow radio astronomer at Cambridge University.
Her Nobel Prize snub would not be the first time Dame Jocelyn Bell Burnell encountered sexism within the field of science. In fact, discrimination against Bell Burnell began as early as her elementary school career. From an early age, Bell Burnell was encouraged by those around her to study physics, and she often occupied her time with her father’s books on astronomy. Her father, an architect who helped construct the Armagh Planetarium, was supportive of such an endeavor. However, in 1948, Bell Burnell was admitted to the Preparatory Departmant of Lurgan College, but was prohibited from studying science—like all other young women in the department. Fortunately, her parents, among others, pushed back against this policy until young girls were permitted to take science courses. When Bell Burnell transferred from Lurgan College to The Mount School in York, England, she sufficiently impressed her physics instructor who went on to serve as her mentor. From the Mount School, she enrolled at the University of Glasgow and obtained a B.S. in Natural Philosophy (physics) with honors in 1965, and immediately pursued her PhD at the University of Cambridge under the tutelage of Anthony Hewish. Interestingly, her decision to pursue a career in radio astronomy versus ‘typical’ astronomy was motivated by the fact that astronomy was a predominately nighttime occupation, and women and men were not permitted to observe together after dark. Conversely, radio astronomy could be done during the day, which permitted her to work alongside her male advisors.
Upon arrival at the University of Cambridge, it was decided that Bell Burnell would work with Hewish and other astrophysicists to construct the Interplanetary Scintillation Array, a radio telescope that would be used to study quasars, which had only recently been discovered. Originally, the Interplanetary Scintillation Array (IPS Array) was a network of fence posts and wires that spanned four acres. It has now been enlarged to cover nine acres, and was re-furbished in 1989. However, the original version was built by Bell Bernell and other scientists by hand, and required two years of intense manual labor. Once the device was completed, Hewish and Bell Burnell were able to use it to monitor high-frequency fluctuations of radio sources. The high-resolution of the IPS Array is what allowed Bell Burnell to detect the presence of pulsars. As stated previously, her advisor would be credited with the discovery and would later go on to win a Nobel Prize with Sir Martin Ryle.
Surprisingly, according to Bell Burnell, she is not bitter over this outcome in spite of the fact that Hewish did not think that Burnell’s “scruffs” were anything to write home about. Hewish was initially quite insistent that the signals detected by Bell Burnell were simply interference. Hewish and Ryle had multiple closed-door meetings on the topic, to which Bell Burnell was not invited. She is quoted as stating:
“First, demarcation disputes between supervisor and student are always difficult, probably impossible to resolve. Secondly, it is the supervisor who has the final responsibility for the success or failure of the project. We hear of cases where a supervisor blames his student for a failure, but we know that it is largely the fault of the supervisor. It seems only fair to me that he should benefit from the successes, too. Thirdly, I believe it would demean Nobel Prizes if they were awarded to research students, except in very exceptional cases, and I do not believe this is one of them. Finally, I am not myself upset about it – after all, I am in good company, am I not!”
Thankfully, Bell Burnell has received numerous well-deserved accolades since her discovery of pulsars. In 2018, she was awarded the Special Breakthrough Prize in Fundamental Physics, a 3 million USD prize. Graciously, she donated each and every cent “to fund women, under-represented ethnic minority, and refugee students to become physics researchers”. These funds were administered by the Institute of Physics. She is now frequently recruited to speak on the role of women in science, and she also serves on various committees to help boost enrollment of women in STEM fields. She was the first woman to be elected as President of the Royal Society of Edinburgh, and she claims that we are all “made of star stuff” and hopes that girls will see her, be inspired, and believe that they have what it takes to be leaders. Bell Burnell certainly has star power, and her continued dedication to academia and research is particularly inspiring given her backstory. We should all take note of her class and grace, and I hope that this article encourages each of you to remember that you are full of “star stuff”—the same stuff that is strong enough to burn bright and strong for millennia.
If you are interested in learning more about Jocelyn Bell Burnell, she was profiled as one of the subjects on the BBC Four three-part series “Beautiful Minds” directed by Jacqui Farnham.
Dr. Sydney Crawley is PhD entomologist with no tolerance for gender bias. Her expertise is bed bug biology and behavior, but she also has an interest in science history and is thankful for all the women that paved the way for her scientific career.
 Backer, D.C. (1984). The 1.5-millisecond pulsar. Annals of the New York Academy of Sciences. https://nyaspubs.onlinelibrary.wiley.com/doi/abs/10.1111/j.1749-6632.1984.tb23351.x
 Bell Burnell, J.S. (1977). “Petit Four- After Dinner Speech Published in the Annals of the New York Academy of Science Dec. 1977. Annals of the New York Academy of Sciences. 302: 685-689.