It’s Time for Supernova Remnant Cassiopeia A to Get the JWST Treatment

Ready for another stunning image from JWST? How about a peek inside a supernova remnant? Not just any stellar debris, but a highly detailed view of the leftovers from the explosion that created Cassiopeia A. The latest image is giving astronomers an up-close and personal look at what happened to a supermassive star some 11,000 light-years away from us. It may also help answer questions about the existence of cosmic dust, particularly in the early Universe.

The Cassiopeia A supernova remnant has been studied a lot. But, the new JWST view shows a great deal more detail that astronomers haven’t seen in other observations. And, that detail is opening up new windows on this stellar event. “Cas A represents our best opportunity to look at the debris field of an exploded star and run a kind of stellar autopsy to understand what type of star was there beforehand and how that star exploded,” said Danny Milisavljevic. He’s the principal investigator of the observing program that captured this view.

Exploring the Damage

This image tells a tale of sequential destruction when the supermassive star at the heart of Cas A died. First, as the aging star began its death process, it consumed heavier and heavier fuels in its core. That heated it up and the star expanded. It also ejected clouds of warm dust. They expanded slowly outward from the event. Then, when the star’s core began to consume iron, it took more energy than the star could supply. Burning stopped and the core collapsed. That brought the rest of the star inward. Then, it all rebounded, sending tendrils of stellar material racing away from the core. Eventually, that material collided with the slower-expanding dust shell.