Skip to main content

James Webb provides a second view of an exploded star

When massive stars run out of fuel and come to the ends of their lives, their final phase can be a massive explosion called a supernova. Although the bright flash of light from these events quickly fades, other effects are longer-lasting. As the shockwaves from these explosions travel out into space and interact with nearby dust and gas, they can sculpt beautiful objects called supernova remnants.

One such supernova remnant, Cassiopeia A, or Cas A, was recently imaged using the James Webb Space Telescope’s NIRCam instrument. Located 11,000 light-years away in the constellation of Cassiopeia, it is thought to be a star that exploded 340 years ago (as seen from Earth) and it is now one of the brightest radio objects in the sky. This view shows the shell of material thrown out by the explosion interacting with the gas that the massive star gave off in its last phases of life.

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.
A new high-definition image from the James Webb Space Telescope’s NIRCam (Near-Infrared Camera) reveals 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. NASA, ESA, CSA, STScI, Danny Milisavljevic (Purdue University), Ilse De Looze (UGent), Tea Temim (Princeton University)

“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 lead researcher Danny Milisavljevic of Purdue University 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.”

Webb has observed Cas A before, using its MIRI instrument. The previous observations taken by MIRI were in the mid-infrared wavelength, which looks more colorful and shows features like the warm dust surrounding the remnant, making up its outer shell, lit up in oranges and red.

This image provides a side-by-side comparison of supernova remnant Cassiopeia A (Cas A) as captured by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument).
From left, this image provides a side-by-side comparison of supernova remnant Cassiopeia A (Cas A) as captured by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument). NASA, ESA, CSA, STScI, Danny Milisavljevic (Purdue University), Ilse De Looze (UGent), Tea Temim (Princeton University)

This recent observation, on the other hand, was observed using NIRCam in the near-infrared wavelength. NIRCam has higher resolution than MIRI, so the image appears somewhat sharper, and it also picks out different details. The dust that glows so brightly in the mid-infrared is barely visible in the near-infrared, appearing as smoke-like wisps. Instead, the NIRCam image shows the inner shell of the remnant more clearly, which helps researchers to learn about how the star shattered when it exploded.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
James Webb finds that rocky planets could form in extreme radiation environment
This is an artist’s impression of a young star surrounded by a protoplanetary disk in which planets are forming.

It takes a particular confluence of conditions for rocky planets like Earth to form, as not all stars in the universe are conducive to planet formation. Stars give off ultraviolet light, and the hotter the star burns, the more UV light it gives off. This radiation can be so significant that it prevents planets from forming from nearby dust and gas. However, the James Webb Space Telescope recently investigated a disk around a star that seems like it could be forming rocky planets, even though nearby massive stars are pumping out huge amounts of radiation.

The disk of material around the star, called a protoplanetary disk, is located in the Lobster Nebula, one of the most extreme environments in our galaxy. This region hosts massive stars that give off so much radiation that they can eat through a disk in as little as a million years, dispersing the material needed for planets to form. But the recently observed disk, named XUE 1, seems to be an exception.

Read more
How astronomers used James Webb to detect methane in the atmosphere of an exoplanet
An artists rendering of a blue and white exoplanet known as WASP-80 b, set on a star-studded black background. Alternating horizontal layers of cloudy white, grey and blue cover the planets surface. To the right of the planet, a rendering of the chemical methane is depicted with four hydrogen atoms bonded to a central carbon atom, representing methane within the exoplanet's atmosphere. An artist’s rendering of the warm exoplanet WASP-80 b whose color may appear bluish to human eyes due to the lack of high-altitude clouds and the presence of atmospheric methane identified by NASA’s James Webb Space Telescope, similar to the planets Uranus and Neptune in our own solar system.

One of the amazing abilities of the James Webb Space Telescope is not just detecting the presence of far-off planets, but also being able to peer into their atmospheres to see what they are composed of. With previous telescopes, this was extremely difficult to do because they lacked the powerful instruments needed for this kind of analysis, but scientists using Webb recently announced they had made a rare detection of methane in an exoplanet atmosphere.

Scientists studied the planet WASP-80 b using Webb's NIRCam instrument, which is best known as a camera but also has a slitless spectroscopy mode which allows it to split incoming light into different wavelengths. By looking at which wavelengths are missing because they have been absorbed by the target, researchers can tell what an object -- in this case, a planetary atmosphere -- is composed of.

Read more
Stunning James Webb image shows the beating heart of our Milky Way
The full view of the NASA/ESA/CSA James Webb Space Telescope’s NIRCam (Near-Infrared Camera) instrument reveals a 50 light-years-wide portion of the Milky Way’s dense centre. An estimated 500,000 stars shine in this image of the Sagittarius C (Sgr C) region, along with some as-yet unidentified features. A vast region of ionised hydrogen, shown in cyan, wraps around an infrared-dark cloud, which is so dense that it blocks the light from distant stars behind it. Intriguing needle-like structures in the ionised hydrogen emission lack any uniform orientation. Researchers note the surprising extent of the ionised region, covering about 25 light-years. A cluster of protostars – stars that are still forming and gaining mass – are producing outflows that glow like a bonfire at the base of the large infrared-dark cloud, indicating that they are emerging from the cloud’s protective cocoon and will soon join the ranks of the more mature stars around them. Smaller infrared-dark clouds dot the scene, appearing like holes in the starfield. Researchers say they have only begun to dig into the wealth of unprecedented high-resolution data that Webb has provided on this region, and many features bear detailed study. This includes the rose-coloured clouds on the right side of the image, which have never been seen in such detail.

A new image from the James Webb Space Telescope shows the heart of our galaxy, in a region close to the supermassive black hole at the center of the Milky Way, Sagittarius A*. The image shows a star-forming region where filaments of dust and gas are clumping together to give birth to new baby stars.

The image was captured using Webb's NIRCam instrument, a camera that looks in the near-infrared portion of the electromagnetic spectrum with shorter wavelengths shown in blue and cyan and longer wavelengths shown in yellow and red.

Read more