Scientists Watch Supernova Shockwave Shoot Through a Dying Star For First Time
For the first time, astronomers captured the shockwave of a supernova bursting through the surface of a dying red supergiant star, revealing a surprisingly symmetrical, grape-shaped explosion. Space.com reports: Seeing this moment in detail has previously been elusive because it's rare for a supernova to be spotted early enough and for telescopes to be trained on it -- and when they have been, the exploding star has been too far away. So, when supernova 2024ggi went boom on April 10, 2024 in the relatively nearby spiral galaxy NGC 3621, which is 22 million light-years away in the constellation of Hydra, the Water Snake, astronomer Yi Yang of Tsinghua University in Beijing knew he had to act.
Although the supernova itself couldn't be resolved as anything put a point of light, the polarization of that light held the clues as to the geometry of the breakout. "The geometry of a supernova explosion provides fundamental information on stellar evolution and the physical processes leading to these cosmic fireworks," said Yang. "Spectropolarimetry delivers information about the geometry of the explosion that other types of observation cannot provide because the angular scales are too tiny," said another team-member, Lifan Wang of Texas A&M University.
The measurement showed that the shape of the breakout explosion was flattened, like an olive or grape. Crucially, though, the explosion propagated symmetrically, and continued to do so even when it collided with a ring of circumstellar material. "These findings suggest a common physical mechanism that drives the explosion of many massive stars, which manifests a well-defined axial symmetry and acts on large scales," said Yang. The findings will allow astronomers to rule out some models and strengthen others that describe what drives the shockwave in a supernova explosion. The findings have been described in a paper on the ESO website.
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