A population of supernova remnants in the nearby galaxy Messier 83 is flickering in brightness, challenging the conventional view that these stellar debris clouds fade slowly and steadily. Astronomers using NASA's Chandra X-ray Observatory captured the unexpected variability over a 14-year period. The findings were presented at the American Astronomical Society meeting in Pasadena, California, and published in The Astrophysical Journal.
The discovery upends a long-held assumption about the aftermath of stellar explosions. Typically, supernova remnants are thought to cool and dim gradually as they expand into space. The rapid brightness changes observed in M83 suggest that some remnants interact with turbulent environments or internal shocks, causing them to flare or dim on much shorter timescales than previously recognized.
Chandra's high-resolution X-ray vision allowed the team to track individual remnants in M83, a spiral galaxy located roughly 15 million light-years away. The data reveals that multiple remnants fluctuated significantly in X-ray output across the observation period. Some brightened sharply, while others faded, indicating dynamic physical processes at work within these structures.
These results could reshape our understanding of how supernova remnants evolve and distribute energy into their host galaxies. The flickering behavior may help astronomers identify which stellar explosions produce neutron stars or black holes, and how such remnants influence star formation. Future observations with Chandra and other observatories will aim to monitor these targets for longer periods to capture the full cycle of variability.
"The fact that these remnants are changing so much in just over a decade is remarkable," one researcher noted. The team hopes to expand the search for flickering remnants in other nearby galaxies to determine how common this phenomenon truly is.