From SOTT:

© NASA

     The shockwave generated by the explosion of an ageing giant star has been observed by an international team of astronomers.

The discovery, accepted for publishing in the Astrophysical Journal, will help scientists understand the life cycle of stars, said study co-author Brad Tucker of the Australian National University.

“This is the first time we’ve seen this in the normal visible colours, and we now know it happens,” Dr Tucker said.

“The fundamental way we believe that core collapse happens is related to this shockwave happening. So the physics has been around … for decades and we’ve finally now been able to physically examine and test what’s going on.”

The team of scientists observed the earliest moments of two old stars exploding using the Kepler Space Telescope.

They spotted the shockwave around the smaller of the two stars — a red supergiant over 270 times the radius of the Sun and 750 million light years away.

As the star ran out of fuel it began collapsing and compressing on its central core.

“It’s like packing in dirt,” Dr Tucker said. “You keep pressing it till it’s so dense you can’t get it in anymore, and that’s when you create a neutron star.

“But you reach a limit when you can’t pack it in anymore, and that force pushing in bounces back and it triggers a shockwave to go through the star, causing the star to actually blow up.”

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