Scientists have begun to unravel the mysteries behind a star's dying moments. Using a new 3D computer model, researchers were able to reconstruct what happens before a star explodes.
Supernovae are stellar explosions that occur when certain types of stars die. This cosmic phenomenon is also the reason why heavier elements exist in the universe. When the universe was young, many ancient stars exploded in bright flashes of energy and light spreading many of the elements known today throughout the universe.
A team of researchers from the University of Arizona and the Max-Planck Institute for Astrophysics were able to create a powerful 3D computer model that recreates the initial process that leads to a star going supernova. The team published their findings in the journal AIP Advances.
When a star starts go undergo the process that will lead to a stellar explosion, what happens is a chaotic and messy chain of events that shows a violent mixing of the elements contained inside a star. These processes cause a star to expand and contract before exploding. Before the actual explosion, the star also begins to emit matter towards space.
"It heats up and burns faster, making more neutrinos and speeding up the process until you have a runaway situation," said W. David Arnett, one of the developers of the 3D model and a Regents Professor of Astrophysics from the University of Arizona.
To create the model, the scientists gathered data from actual supernova by measuring radioactivity and light. The researchers then used the data they gathered to construct the 3D model that could recreate the necessary physical processes that could lead to existing data on supernovae.
Due to the sheer complexity of a supernova, the earlier computer models were often very large and difficult to understand. To push through with their study, the scientists had to simplify their model by making certain assumptions about how stellar materials behaved.
"We still have the concentric circles, with the heaviest elements in the middle and the lightest elements on top, but it is if someone put a paddle in there and mixed it around," Arnett said. As we approach the explosion, we get flows that mix the materials together, causing the star to flop around and spit out material until we get an explosion."
Even with the current model, the scientists are hoping to observe more supernovae in space to fine tune the existing model with the addition of new data. However, the current model has helped scientists bridge the large gap in knowledge regarding these massive stellar explosions.
"Instead of going gently into that dark night, it is fighting. It is sputtering and spitting off material. This can take a year or two. There are small precursor events, several peaks, and then the big explosion." Arnett said.
