Explosions are among the most thrilling phenomena in the cosmos. Astronomical explosions are some of the most efficient drivers of change and chemical evolution in the Universe. Plus, they are beautiful and simple to detect… as long as we can see them.
In 2007, a team led by astronomer Luncan Lorimer found that this may not always be the case. Buried among old archival observations, they detected a really short flash of radio waves of unknown origin,. This soon motivated more scientist to search for more of these explosions with their radio antennas. Surprisingly, these millisecond pulses, known as Fast Radio Bursts (FRBs), could be continuously detected from all directions in space. With no found optical counterpart, the origin of these signals has remained a mystery until recently, signaling the end of a 20-year-old race to identify the origin and physics behind FRBs.
To the present day, around a thousand FRBs have been detected, from as close as the Milky Way to as far as billions of light years away. Most of them are a one-off event, while around 10% are known to repeat cyclically. And of course, theories trying to explain this odd nature have been abundant. They could result from the merger/collapse/interaction of compact objects such as neutron stars, white dwarfs and even black holes. Some have pointed at supernovae, active galactic nuclei or magnetars as the emitters of these signals. Finally, other astronomers did not miss the chance to propose more exotic theories such as white hole explosions or even alien light sails.
Although it is soon to discard any theory yet, a team led by astronomer Kenzie Nimmo probed this past January 2025 that a fast rotating neutron star (a.k.a. a magnetar) was the progenitor of the as-yet non-repeating FRB 20221022A. Even though we still have much to learn about FRBs, this discovery will have a major impact in the field of cosmic transient phenomena. International collaborations all over the world will continue working on the matter, and it will not take long for them to be back with the next “bang”.
MSc in Astrophysics and Particle Physics.
PhD candidate working in the field of Galaxy Evolution and Large Scale Structure.