Like hundreds of millions of suns: a mysterious radiation from deep space has an unexpected origin.

Fast Radio Bursts (FRBs) last only a fraction of a second and are extremely powerful bursts of radiation that can only be detected using radio telescopes. During that brief moment, they release as much energy as several hundred million Suns. Astronomers believe that FRBs are caused by changes in the magnetic fields of magnetars, which are neutron stars with the strongest magnetic fields in the universe. However, fast radio bursts still remain a significant mystery. A recent discovery described in a study published in The Astrophysical Journal Letters has come as a major surprise to astronomers. It turns out that FRBs can occur in places no one expected, as reported by ScienceAlert.

Astronomers know that some FRBs occur multiple times, and these powerful radiation bursts are referred to as repeating fast radio bursts. One such phenomenon, named FRB 20240209A, was first detected in February of last year. Astronomers observed radiation bursts 21 times by June, allowing for a thorough investigation of this FRB.

Astronomers made several unexpected discoveries. It was found that this FRB originated in a very ancient galaxy located 2 billion light-years away from us. Typically, fast radio bursts arise in the centers of galaxies, where star formation is more prevalent, and thus more neutron stars are present. However, FRB 20240209A appeared on the outskirts of the galaxy.

According to scientists, this galaxy is over 11 billion years old, indicating that the star formation process ceased there a long time ago. The fact that this FRB occurred in an old and essentially dead galaxy suggests that the neutron star responsible for the powerful radiation burst is also very old.

It is generally thought that FRBs originate from very young magnetars. However, since neutron stars cannot generate new heat, they cool down and become inactive over time. Therefore, astronomers would not expect to see an old neutron star producing a fast radio burst. Yet this discovery shows that it is indeed possible.

On the other hand, the authors of the study believe that this FRB may not have originated on the edge of the ancient galaxy, but rather in a very dense globular star cluster that orbits around it. This galaxy is too far away for us to determine the accuracy of this hypothesis. However, it is known that mergers of stars often occur in globular star clusters. Thus, FRB 20240209A could have resulted from the merger of two magnetars.

To fully understand the mysterious FRB 20240209A, astronomers need to conduct further observations, but it is now clear that the astrophysical processes that create FRBs are more diverse than previously thought.