A cosmic spotlight in the form of a supernova flash has illuminated interstellar material between the stars, revealing intricate layers of dust and gas for the first time. NASA’s James Webb Space Telescope (JWST) is providing unprecedented details about the composition and structure of this material.
The observation took place in the constellation of Cassiopeia, where a shockwave from the collapse of a massive star created a brief, intense pulse of X-rays and ultraviolet light. This pulse reached interstellar material 350 years later, warming it and causing it to glow in infrared light.
JWST’s Near-Infrared Camera (NIRCam) captured images that show fine details resembling knots and whorls of wood grain. These observations allow astronomers to map the true 3D structure of the interstellar medium for the first time.
“We see layers like an onion,” said Josh Peek, a member of the science team at the Space Telescope Science Institute. “We think every dense, dusty region looks like this on the inside.”
The images also show sheet-like structures and dense, tightly wound regions that resemble magnetic islands embedded within the interstellar medium’s magnetic fields.
“This is the astronomical equivalent of a medical CT scan,” explained Armin Rest, another member of the science team. “We have three slices taken at different times, which will allow us to study the true 3D structure.”
The JWST is set to target the light echo multiple times, weeks or months apart, to observe how it evolves as the light echo passes by. This research may shed light on the formation and destruction of molecules in these interstellar regions.
As the world’s premier space science observatory, JWST is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it.
Source: https://webbtelescope.org/contents/news-releases/2025/news-2025-102