First 3D image of exploding star

The remains of an exploding star have been reconstructed in a 3D image for the first time, say scientists.

Astronomers, including one at Cardiff University, used medical imaging techniques to help create the hologram of Cassiopeia A.

Dr Haley Gomez, from the university's physics and astronomy school, said it provided "an amazing insight into the original explosion of the star".

The image shows disc-shaped jets came out from the star as it exploded.

ONION-LAYER DIAGRAM

• Each of the different components in the 3D reconstruction relates to a layer in the onion-skin structure of the progenitor star.
• The outer carbon layer came off spherically, driving a spherical blast wave that sets up a spherical reverse shock
• The inner neon/oxygen, silicon/argon (yellow), iron (green) layers came off flattened with high velocity plumes and jets that caused distortions in the reverse shock
• Source: Cardiff University

Astronomers knew that plumes and jets emerged from stars but the broad, disc-like structure is a new discovery.

The international team used x-ray images and infrared data to create the visualisation and get a more complete understanding of the explosion.

Cassiopeia A is a supernova remnant, the debris from a star that blew itself apart some 11,000 light-years from Earth. The light from the explosion is thought to have first arrived at Earth about 330 years ago.

Dr Gomez said the reconstruction was "really extraordinary".

"Astronomers and the public are used to seeing flat 2D pictures, far removed from our everyday 3D life.

"Now, we can visualise an object 11,000 light-years away from different angles."

The project was led by Dr Tracey DeLaney of the Massachusetts Institute of Technology, US.

She said: "We have always wanted to know how the pieces we see in two dimensions fit together with each other in real life. Now we can see for ourselves with this 'hologram' of supernova debris."

In the film, released by the astronomers, the green region is mostly iron observed in X-rays. The yellow region is a combination of argon and silicon seen in X-rays, optical, and infrared - including jets of silicon. The red region is cold debris seen in the infrared. Finally, the blue reveals the outer blast wave, most prominently detected in X-rays.

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Cardiff University
Massachusetts Institute of Technology
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