Max Planck Institute for Astrophysics | 2020 Jan 23
Some unidentified features in one of the brightest stellar explosions ever witnessed, SN 2006gy, have now been explained by researchers at the Max Planck Institute for Astrophysics. The spectral lines arise from neutral iron - very unusual for such a high-energy event - and imply that more than a third of a solar mass of this heavy element was created. The dominance of iron in the spectrum rules out several previously proposed scenarios for SN 2006gy and instead opened up the door for a new one.
Superluminous supernovae are the brightest explosions in the cosmos. Over a few months they radiate as much energy as the Sun does over its entire lifetime, reaching a peak brightness exceeding that of an entire galaxy. The origin of this energy, and what kind of stellar progenitor system has exploded, are still unclear.
One of the most studied such objects is SN 2006gy, which was first observed in 2006. It showed signs of interaction between the supernova explosion and circumstellar material, which had been ejected previously. Many theories have been put forth for SN 2006gy, including collision of shells ejected subsequently by a very massive star, large amounts of radioactivity, or a massive stellar explosion called a core-collapse supernova, which arises when the compact core of a massive star collapses to a neutron star, interacting with its own wind. ...
A type Ia supernova at the heart of superluminous transient SN 2006gy ~ Anders Jerkstrand, Keiichi Maeda, Koji S. Kawabata
- Science 367(6476):415 (24 Jan 2020) DOI: 10.1126/science.aaw1469