After upgrading their radio telescopes in Westerbork, the Netherlands, astronomers found five new fast radio bursts. Much clearer images from the telescope than previously possible showed multiple flares piercing our nearby Triangulum galaxy. This allowed astronomers to determine for the first time the maximum number of invisible atoms in this galaxy. The results were published on April 12. Astronomy and Astrophysics.

Fast radio bursts, FRBs, are some of the brightest bursts in the universe. Explosions mainly emit radio waves. The flares are so strong that radio telescopes can detect them at a distance of more than 4 billion light-years. Long-term vision at such great distances means that flares contain enormous amounts of energy. When extinguished, one FRB contains ten trillion (ten million times a million) annual energy consumption of the entire world population.

This huge generation of energy makes FRBs extremely interesting. Many astronomers believe they are emitted by neutron stars. The intensity and strength of the magnetic field of these extremely compact stars is unmatched in the universe. By studying flares, astronomers try to better understand the fundamental properties of the matter that makes up the universe. But studying these outbreaks is difficult. No one knows where the next explosion will be in the thunder. And FRBs only last milliseconds: If you blink, you’ll miss it.

Thanks to new receivers and a new supercomputer (Apertif Radio Transient System, ARTS), Westerbork discovered five new FRBs. Chief inspector Joeri van Leeuwen (ASTRON) also immediately identified them, he says. “We now have a vehicle with a very wide field of view and very clear vision. And it’s all alive. It’s new and exciting.”

Previously, radio telescopes like Westerbork detected FRBs as the compound eyes of a fly. Flies can be seen from all directions but are blurred. The Westerbork update is like a fly’s eye crossed by an eagle’s eye. The ARTS supercomputer continuously combines images from twelve Westerbork bowls to create a clear image over a wide field of view.

“You can’t just buy the complex electronics you need to do this,” says systems architect Erik Kuystra (ASTRON). “With a large team, we developed most of the system ourselves. This led to the creation of a cutting-edge machine, one of the most powerful in the world.”

Astronomers want to understand how and why FRBs become so bright. But the flares are also interesting because they penetrate other galaxies on their way to Earth. Electrons in these galaxies, often mostly invisible, distort the flares. Watching the invisible electrons and their accompanying atoms is important because most of the matter in the universe is dark, and we still don’t know much about it.

Previously, radio telescopes could only show roughly where an FRB was occurring. The ARTS supercomputer now allows Westerbork to pinpoint the exact location of the FRB with great precision. Van Leeuwen says: “We showed that the three FRBs we discovered were affecting our nearby Triangulum Galaxy. So for the first time we were able to calculate how many invisible electrons this galaxy contains. A great result.”