Overview
- Researchers reported in Nature Communications that a faint supernova remnant called G189.6+3.3 was identified next to the well-known IC 443 Jellyfish Nebula using multiwavelength data.
- The team used 16 years of Fermi gamma-ray observations stacked with X-ray data from eROSITA and archival ROSAT images to isolate a gamma-ray shell that matches the X-ray structure of G189.6+3.3.
- Region-by-region gamma-ray spectra show the remnant’s north emits proton-driven gamma rays where it hits the dense S249 H II cloud while other areas show electron-driven emission, linking both remnants to the same environment.
- Statistical tests and simulations give a low chance of coincidence—about one in 1,000—and models suggest the two explosions occurred within thousands to tens of thousands of years after one another following a bound binary evolution.
- The authors call the system a candidate and plan targeted searches for more examples because confirming paired supernova remnants would let astronomers constrain how massive binaries evolve and how shocks accelerate cosmic particles.