Chandra Spots Youngest Supernova In The Milky Way

Approximately 140 years ago, in the center of the Milky Way, a stellar explosion gave birth to what we call today the youngest supernova in our galaxy. The discovery was made by NASA’s Chandra X-ray Observatory and the National Radio Astronomy Observatory’s Very Large Array, and scientists hope to further understand the mechanisms of these explosions and how often they occur in the Milky Way.

The supernova, which lies in the constellation Sagitarius, is much younger than originally estimated. The first observations of the supernova began in 1985, when a team of scientists led by David Green of the University of Cambridge identified the supernova with the help of the Very Large Array and estimated it to have originally exploded 400 to 1,000 years ago.

However, over two decades of observations have concluded that, based on the rate of expansion of its remains, approximately 16 percent, the supernova is much younger (the faster the rate of expansion, the younger the supernova) than previously estimated, which makes it even younger than Cassiopeia A, the last known supernova in our galaxy which occurred around 1680.

The explosion of the supernova has not been detected by optical telescopes due to the fact that it is embedded in a field of gas and dust. However, when such explosions occur, the supernova remnants cause bursts of radiation, which can be detected by X-ray and radio telescopes. According to experts’ estimations, approximately three supernovae explode every century in the Milky Way.

Dr. Green estimated that there should be approximately 10 supernova remnants in the Milky Way, all younger than Cassiopeia A, and this is just one of them.

However, this supernova is not all about the age. According to Stephen Reynolds of North Carolina State University in Raleigh, who led the Chandra study, this supernova is like no other object in the galaxy and needs further study. The high expansion velocities and extreme particle energies are essential for understanding how stars explode and what happens in the aftermath, he said.

The findings will be published in The Astrophysical Journal Letters.