How massive sloshing stars make fiery supernovas

BY Rebecca Jacobson  February 20, 2014 at 6:17 PM EST
Photo by NASA/JPL-Caltech/CXC/SAO

Scientist at NASA believe they have discovered the final acts of a dying star, before it explodes into a supernova. Photo by NASA/JPL-Caltech/CXC/SAO

Scientists believe they have finally captured what happens in the heart of a star before it explodes in a supernova. With the help of NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR), scientists mapped how shockwaves rip apart dying stars. Their findings were published this week in the journal Nature.”

When stars at least eight times more massive than our sun die, they explode. The heat and force of the blast fuses light particles and elements together to form the gold that ends up in our jewelry, the calcium found in our bones, and the iron in our blood.

NuSTAR is showing that exploding stars slosh around before blasting apart. This 3-D computer simulation demonstrates how the supernova explosion might look. Video by NASA Jet Propulsion Laboratory

By studying computer simulations scientists found when the star dies and collapses, the main shockwave stalls, and the star won’t explode. Using NuSTAR, scientists studied the radioactive remnants of supernova Cassiopeia A, searching for the clues about the blast. They found that the insides of an exploding star slosh and churn. That churning restarts the shockwave, and the star explodes.

“Stars are spherical balls of gas, and so you might think that when they end their lives and explode, that explosion would look like a uniform ball expanding out with great power,” said Fiona Harrison, co-author of study and the principal investigator of NuSTAR at the California Institute of Technology. “Our new results show how the explosion’s heart, or engine, is distorted, possibly because the inner regions literally slosh around before detonating.”