JWST Is Imaging "A Shimmering, Waving Curtain" Of Warmed Gas & Dust, Hundreds Of Light Years Across -- At Cassiopeia A.

Once upon a time, the core of a massive star collapsed, creating a shockwave that blasted outward, ripping the star apart as it went. When the shockwave reached the star’s surface, it punched through, generating a brief, intense pulse of X-rays and ultraviolet light that traveled outward into the surrounding space. About 350 years later, that pulse of light has reached interstellar material, illuminating it, warming it, and causing it to glow in infrared light.

Those ripples appear as wood-grain brown in the images at right. Here's the whole jaw-slacking story, from NASA:

. . .[These images show a] shimmering cosmic curtain [of] interstellar gas and dust that has been heated by the flashbulb explosion of a long-ago supernova. The gas then glows infrared light in what is known as a thermal light echo. As the supernova illumination travels through space at the speed of light, the echo appears to expand. NASA’s [JWST] observed this light echo in the vicinity of the supernova remnant Cassiopeia A. . . .

The researchers targeted a light echo that had previously been observed by NASA’s retired Spitzer Space Telescope. It is one of dozens of light echoes seen near the Cassiopeia A supernova remnant – the remains of the star that exploded. The light echo is coming from unrelated material that is behind Cassiopeia A, not material that was ejected when the star exploded.

The most obvious features in the [JWST] images are tightly packed sheets. These filaments show structures on remarkably small scales of about 400 astronomical units, or less than one-hundredth of a light-year. An astronomical unit, or AU, is the average Earth-Sun distance. Neptune’s orbit is 60 AU in diameter. . . .

What an amazing place the interstellar medium -- between our systems -- must be. Daunting, austere and almost. . . hostile. . . but gorgeous! Smile. . . .

नमस्ते