Study describes mechanism behind Supernovae - star explosions

Researchers have developed a theory that can describe the nuclear reaction behind supernovae or star explosions.

Researchers have developed a theory to describe the mechanism behind supernovae, bright and powerful explosion of stars. The new study, published in the journal Science, could help clear things up considerably. The study noted that one of the processes triggering the nuclear reaction behind stellar explosions was the formation of a mysterious supersonic reaction wave called detonation. These enigmatic waves are believed to travel faster than the speed of sound and are capable of burning up all of the star's material before dispersing into the vacuum of space.

The new study could also have some applications on Earth-based combustion systems, potentially leading to improved propulsion systems for aircraft and spacecraft and more efficient power generation.

Researchers also demonstrated the process of detonation formation from a slow flame during the study by using both experiments and numerical simulations that were carried out on some of the largest supercomputers in the US. The results were applied to predict the conditions of detonation formation in one of the classical theoretical scenarios of a type of stellar explosion called Type IA supernovae.

According to the study, this type of explosion happened when carbon and oxygen atoms are packed densely into around 1,000 tons per cubic centimeter in a star's core, and start burning to high temperatures in rapid nuclear reactions. The researchers claimed that a star is disrupted in a matter of seconds by the resulting explosion.

The study also noted that it must be confined within a wall like setting with obstacles, or boundaries, confining the pressure waves released from the burning or the detonation may not occur. The researchers said that shock waves form and grow in strength with increasing pressure, to the point when they can compress the reacting mixture igniting it and produce a self-sustaining supersonic boundary.

A unified theory about turbulence-induced detonation that was developed by researchers describe the mechanism and conditions for initiating the enigmatic process in thermonuclear explosions. A reactive mixture, which burns and releases energy, when stirred up to create intense turbulence, builds up a catastrophic instability and may rapidly increase the pressure in the system which goes on to produce strong shocks that ignite a detonation, the researchers noted.

Similarities between thermonuclear combustion waves and chemical combustion waves on Earth helped them use their findings to predict the conditions for detonation formation in Type 1A supernovae, they said. Both these waves are controlled by the same physical mechanisms.