Written by Lola Gayle
Explosions on Earth typically occur quite rapidly, lasting only seconds. But explosive supernovae in space can take months to fizzle out. This slowness is what allows scientists to study a supernova’s dynamics in greater detail.
Using that slowness to their advantage, scientists have captured the early death throes of supernovae for the first time. And what they found was quite surprising. Supernovae – the universe’s benchmark explosions – are much more varied than originally expected.
Using the Kepler space telescope, the scientists photographed three type 1a supernovae in the earliest stages of ignition. They followed them through to full brightness around three weeks later, and then watched the subsequent decline over the next few months.
According to a statement from ANU, “They found the initial stages of a supernova explosion did not fit with the existing theories.”
“The stars all blow up uniquely. It doesn’t make sense,” said Dr. Brad Tucker, from the ANU’s Research School of Astronomy and Astrophysics.
“It’s particularly weird for these supernovae because even though their initial shockwaves are very different, they end up doing the same thing.”
Before this study, astronomers had theorized that all supernovae followed an identical pattern due to the fact that the earliest type 1a supernovae had been glimpsed was more than 2.5 hours after ignition.
Previously, it was believed that supernovae occurred “when a dense star steadily sucked in material from a large nearby neighbor until it became so dense that carbon in the star’s core ignited.”
“Somewhat to our surprise the results suggest an alternative hypothesis, that a violent collision between two smallish white dwarf stars sets off the explosion,” said lead researcher Dr. Robert Olling, from the University of Maryland.
Brighter than the billions of stars in their galaxy, supernovae help astronomers calculate distances to galaxies.
Measurements of distant supernovae have also led to the discovery dark energy causes the accelerated expansion of the universe. Brian Schmidt from the ANU, Saul Perlmutter (Berkeley) and Adam Reiss (Johns Hopkins) were awarded the Nobel prize in 2011 for this discovery.
Dr. Tucker said the new results did not undermine the discovery of dark energy.
“The accelerating universe will not now go away – they will not have to give back their Nobel prizes,” he said.
“The new results will actually help us to better understand the physics of supernovae, and figure out what is this dark energy that is dominating the universe.”
The findings are published in Nature.
This report is based on materials provided by ANU.
Image Above: Supernova SN2012fr, just below the center of the host galaxy, outshone the rest of the galaxy for several weeks. Credit: Brad Tucker and Emma Kirby. Full size image available here.
This post is also available at STEAMRegister.com.