The Cassiopeia A supernova remnant, taken from the James Webb Space Telescope's NIRCam. Image: NASA/ ESA/CSA/STScI/D Milisavljevic (Purdue University)/T Temim (Princeton University)/I De Looze (University of Gent)
Using the powerful instruments of the James Webb Space Telescope, researchers have found new features in the remains of this exploded star, including a ‘green monster’.
The James Webb Space Telescope has managed to uncover new and unexpected features deep within the remnant of a supernova.
The powerful space observatory turned its gaze to Cassiopeia A (Cas A), which is one of the most well-studied remains of an exploding star, having been examined by various telescopes in the past. This remnant is located 11,000 light-years away and is estimated to have exploded about 340 years ago from our point of view.
While it has already been observed in detail, the stunning new images reveal more features that may further our understanding of this cosmic phenomenon.
The first image was taken using Webb’s Near-Infrared Camera (NIRCam) and shows a lot of activity contained within the supernova remnant. This image was made by assigning colours to different filters on the camera.
The image shows clumps of bright orange and light pink that make up the inner shell of the supernova remnant. The image shows various clumps of gas, which is believed to be comprised of sulphur, oxygen, argon and neon from the star itself. The dust and molecules contained in this remnant could eventually become parts of new stars and planets.
“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 Dr Danny Milisavljevic of Purdue University, who leads the research team. “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.”
But other details are presented when James Webb used its mid-infrared instrument (MIRI) to gaze into the remnant. This image presents a more powerful form of colour, with additional green swirls that aren’t visible in the NIRCam image.
A comparison of two Cas A images, taken with the James Webb’s NIRCam on the left and MIRI on the right. Image: NASA/ESA/CSA/STScI/D Milisavljevic (Purdue University)/T Temim (Princeton University)/I De Looze (University of Gent)
NASA said some of the dust is too cool to be detected directly at near-infrared wavelengths, but is lit up when shown in mid-infrared. The loop of green light in the central cavity of Cas A was nicknamed the ‘green monster’ by the research team and was described as “challenging to understand” at first.
The circular holes that are visible in the MIRI image are faintly outlined in white and purple emission in the NIRCam image. The researchers said this is ionised gas and believe it is from supernova debris pushing through and sculpting gas left behind by the star before it exploded.
Last month, the James Webb Space Telescope looked at another remnant of a supernova known as the Crab Nebula, to gain further insights into these cosmic phenomena.
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