(Web Desk) - Cassiopeia A is one of the most well-studied supernova remnants in our universe.
Discovered in 1948, it is the leftover dust and gas of a gargantuan explosion that occurred when a star 11,000 light-years away from Earth died.
But despite how many times astronomers have looked at the remnant, a brand-new image created by scientists using the James Webb Space Telescope were shocked by what they saw.
Namely, some of Cassiopeia A seems to be missing.
Here's the deal: In April, scientists used the Webb Telescope to look at Cassiopeia A in the mid-infrared light range. While that light is invisible to humans, it revealed a tempestuous state of affairs in the heart of the remnant including vast clouds of oxygen, argon, and neon gasses, as well as swirling dust.
But when scientists took another peek, this time using the Webb Telescope's near-infrared camera, almost all the bright green and pink gas captured in the April image appears to be gone.
Which begs the question: What happened to it? The mystery could help astronomers piece together exactly what the supernova looked like as it happened.
The new image — on the left — reveals strange circular holes in the center of the remnant, outlined by white and purple gas. This appears to be the result of ionized gas, emitted before the star exploded and then shaped by debris thrown off as it went supernova.
Also noticeable in the newest image is what looks like smoke coming from the remnant — this is caused by the explosion. As the blast ripples out into space, it hits the cold matter around it. Because it is so cold, it can't be seen in near-infrared but it does appear in mid-infrared.
Shockingly, the image also shows light echoes that look like new supernovas — most notable among them is a bright blob at the bottom right of the new image which scientists have dubbed "Baby Cas A."
In truth, this echo was created when gas thrown off by the initial supernova hit and warmed up dust some 170 light-years away — as the dust cools, it glows.
“With NIRCam’s resolution, we can now see how the dying star absolutely shattered when it exploded, leaving filaments akin to tiny shards of glass behind,” said Danny Milisavljevic of Purdue University, who leads the research team, in a statement.
“It’s really unbelievable after all these years studying Cas A to now resolve those details, which are providing us with transformational insight into how this star exploded.”