March 17, 2021
New research solves a decades-long riddle: from where do the highest-energy cosmic rays originate? Even supernovae – exploding stars – can’t explain them. Now it seems these sorts of cosmic rays may come from clusters of young, hot, massive stars.
Cygnus OB2 is the nearest star-forming region to us. It’s what’s called an OB association, meaning it contains some of the most massive and luminous stars known. Scientists found cosmic rays of the highest energies to originate from this region of space. The colors – green to yellow to red – represent high-energy gamma-ray emission as seen by the HAWC observatory, overlaid on an infrared image from the Spitzer telescope (the white regions). Image via B. Hona (HAWC Collaboration)/ Hora et. al (Spitzer)/ Los Alamos National Laboratory.