Strong Infrared Emission Explains Origin of Extraordinary Supernova

A new study conducted by researchers from Japan revealed that the presence of strong infrared emissions in extraordinary supernovae might explain the origin of this type of supernovae, which are brighter than the normal ones.

The study, published in the Publications of the Astronomical Society of Japan, suggests that dense gas surrounding a pre-supernovae-explosion star system might explain how extraordinary supernovae were formed and why is it brighter than normal supernovae.

Previously, researchers have been debating the origins of extraordinary supernovae. They are divided into two popular scenarios, both involving a binary system. The first scenario, called accretion, is composed of one white dwarf and one normal star orbiting around each other. On the other hand, the second scenario, dubbed as merger, involves two white dwarfs orbiting each other.

For the study, researchers observed the 'extraordinary supernovae' candidate SN 2012dn using 11 telescopes in Japan through OISTER (Optical and Infrared Synergetic Telescopes for Education and Research) for 150 days after its initial observation.

According to their press release, the researchers discovered the presence of a strong infrared emission from the object, which cannot be usually seen in a typical supernova. Further analysis of the infrared emissions revealed that material ejected recently from the progenitor system is the one responsible for the emission.

Their findings strongly support the accretion scenario. According to the researchers, materials escape from the potential gravity of the system during the transfer of gas from the normal star onto the surface of the white dwarf. These materials surround pre-supernovae-explosion star system, forming a dense gas.

Understanding the origin of extraordinary supernovae and Type Ia ("One-A") supernovae are very significant in studying the origins of the universe. Type Ia supernovae have been widely used as reference because the physics governing their evolution ensures that they all change from a stable state to an explosion at almost exactly the same point in their evolution. However, other studies involving Type Ia supernovae were contaminated by the extraordinary supernovae, skewing the calibration.

Researchers are now planning to determine if the accretion scenario may also apply in the formation of Type Ia supernovae.