File:Cassiopeia A (NIRCam Image) (2023-149).png

English: A new high-definition image from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) unveils intricate details of supernova remnant Cassiopeia A (Cas A), and shows the expanding shell of material slamming into the gas shed by the star before it exploded.

The most noticeable colors in Webb’s newest image are clumps of bright orange and light pink that make up the inner shell of the supernova remnant. These tiny knots of gas, comprised of sulfur, oxygen, argon, and neon from the star itself, are only detectable by NIRCam’s exquisite resolution, and give researchers a hint at how the dying star shattered like glass when it exploded. The outskirts of the main inner shell looks like smoke from a campfire. This marks where ejected material from the exploded star is ramming into surrounding circumstellar material. Researchers say this white color is light from synchrotron radiation, which is generated by charged particles traveling at extremely high speeds spiraling around magnetic field lines. There are also several light echoes visible in this image, most notably in the bottom right corner. This is where light from the star’s long-ago explosion has reached, and is warming, distant dust, which is glowing as it cools down.

NASA, ESA, CSA, STScI, Danny Milisavljevic (Purdue University), Ilse De Looze (UGent), Tea Temim (Princeton University)