Scientists have conclusively identified a source in the Milky Way that can accelerate protons to some of the highest energies known in our galaxy. The discovery could help researchers better understand cosmic rays, the extremely fast particles that travel through the space between stars and affect events throughout the galaxy.
Cosmic rays consist mostly of protons, along with a much smaller number of electrons. Some reach energies greater than those produced by human-built particle accelerators. The Large Hadron Collider on the border of Switzerland and France can propel protons to nearly the speed of light, yet the natural accelerators found in space can push particles to even more extreme energy levels.
An international research team led by Hiroshima University confirmed the galactic accelerator after combining observations from three major observatories operating on Earth and in space. The results were published in The Astrophysical Journal on July 16, 2026.
A Natural Accelerator With Extraordinary Power
"This immense energy makes cosmic rays important in astronomy and astrophysics," said first and corresponding author of the study Tsunefumi Mizuno, associate professor at Hiroshima University's Hiroshima Astrophysical Science Center.
