1943

Discovery of pulsars

Astrophysicists Jocelyn Bell Burnell discovered pulsars. A pulsar is a big star that shrunk, resulting into an object of very large density. This object is spinning itself around and has a magnetic field axis, emitting radio signals to us in a pulsating way, depending whether the beam is facing us or not.

During her PhD research Jocelyn Bell Burnell examined radio frequencies from celestial objects. Looking for new quasars, which are very big black holes, she raised the number of known quasars at the time from 20 to about 200. And in the process, she discovered a new signal that indicated something different from what was already known to exist in the universe. She noticed that this signal was "coming and going", like a pulse. Digging into this new signal and what it could mean, Jocelyn Bell Burnell discovered the pulsars!

Interesting to hear from her story is how she scanned the radio frequencies along more than 5 km of paper, and she not only discovered the first pulsar, but more afterwards!

While her discovery was deemed of great importance for radio astronomy, it was her supervisor, Antony Hewish, who received the Nobel Prize in Physics 1974 “for his decisive role in the discovery of pulsars", shared with Martin Ryle.

In 2018 Jocelyn Bell Burnell received the Breakthrough Prize for the discovery of pulsars, and she donated the 3 million dollar prize to set up a fund for postgraduate students in physics from minorities in the field.

On top of her scientific achievements, Jocelyn Bell Burnell devotes her career to be a role model for women in science and to give minority people the opportunity to do research. She provides time, expertise, and resources for this purpose.

We, the Wall of Scientists, had the great pleasure to meet her and told her about this initiative. She was flattered and thank us. But it is us who should thank her for being an outstanding role model for all of us. Thank you Jocelyn.

Written by: Enriqueta Vallejo-Yagüe.