Chandra X-ray Observatory Detects Unexpected Supernova Remnant Variability in Messier 83
NASA’s Chandra X-ray Observatory has revealed surprising and dramatic changes in the brightness of supernova remnants within the nearby spiral galaxy Messier 83 (M83). Astronomers typically expect the debris from stellar explosions to fade slowly over time, making these observations unexpected. Over 14 years of data, roughly half of 22 observed X-ray sources associated with supernova remnants exhibited significant variability. Researchers propose that these fluctuations are likely caused by high-mass X-ray binaries (HMXBs). In this scenario, a surviving companion star orbits a compact object—either a black hole or a neutron star—left behind by a supernova, with material being pulled from the star and heated to emit X-rays.
NASA’s Chandra X-ray Observatory has detected unexpected dramatic changes in the brightness of supernova remnants within the nearby spiral galaxy Messier 83 (M83). This finding challenges previous understandings that the debris from stellar explosions, known as supernovas, typically fades slowly over time.
Researchers analyzed 14 years of Chandra data, collected between 2000 and 2014, from M83. The galaxy is located approximately 15 million light-years from Earth and is known for its high rate of star formation. The team found surprising variations in the X-ray brightness of sources previously identified as supernova remnants.
Roughly half of the 22 X-ray sources associated with supernova remnants in their sample displayed changes in X-ray brightness over the 14-year observational period. Andrea Prestwich of the Catholic University of America, who led the study, expressed surprise at the widespread variability, noting that while individual X-ray sources can vary, finding so many supernova remnants behaving this way was unexpected.
While one variable remnant, SN 1957D, could be explained by its interaction with surrounding material, this explanation does not account for the majority of the observed variability.
One likely explanation suggests the presence of a population of stellar survivors. In this scenario, each variable X-ray source originated as a pair of massive stars. One star exploded as a supernova, leaving behind either a black hole or a neutron star, while its companion survived.
Co-author Michael McCollough of the Center for Astrophysics | Harvard & Smithsonian (CfA) explained that in such systems, the black hole or neutron star can pull material from the surface of the massive companion star. This infalling material becomes superheated due to intense gravitational forces, thereby producing the X-rays detected by Chandra.
These systems are known as high-mass X-ray binaries (HMXBs) and are recognized as some of the most variable X-ray sources in the universe. Astronomers suggest that HMXBs are likely the cause of the brightness fluctuations observed in M83’s supernova remnants. The new results were presented at the American Astronomical Society meeting in Pasadena, California, and published in The Astrophysical Journal.
According to NASA Breaking News, the findings indicate something unusual is occurring in these stellar objects.
