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.”

Recommended Videos

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.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
James Webb takes rare direct image of a nearby super-Jupiter
Artist’s impression of a cold gas giant orbiting a red dwarf. Only a point of light is visible on the JWST/MIRI images. Nevertheless, the initial analysis suggests the presence of a gaseous planet that may have properties similar to Jupiter.

Even with huge ground-based observatories and the latest technology in space-based telescopes, it's still relatively rare for astronomers to take an image of an exoplanet. Planets outside our solar system are so far away and so small and dim compared to the stars they orbit that it's extremely difficult to study them directly. That's why most observations of exoplanets are made by studying their host stars. Now, though, the James Webb Space Telescope has directly imaged a gas giant -- and it's one of the coldest exoplanets observed so far.

The planet, named Epsilon Indi Ab, is located 12 light-years away and has an estimated temperature of just 35 degrees Fahrenheit (2 degrees Celsius). The fact it is so cool compared to most exoplanets meant that Webb's sensitive instruments were needed to study it.

Read more
One half of this wild exoplanet reaches temperatures of 1,450 degrees Fahrenheit
webb wasp 39b dayside nightside stsci 01j2f12rm1s3n39yj938nhsf93 png

This artist’s concept shows what the exoplanet WASP-39 b could look like based on indirect transit observations from JWST and other space- and ground-based telescopes. Data collected by its NIRSpec (Near-Infrared Spectrograph) show variations between the morning and evening atmosphere of the planet. NASA, ESA, CSA, Ralf Crawford (STScI)

One of the ground-breaking abilities of the James Webb Space Telescope is that researchers can use it to not only detect distant planets but also to peer into their atmosphere. Now, new research using Webb has uncovered differing conditions between morning and evening on a distant exoplanet, the first time such differences have been observed on a planet outside our solar system.

Read more
Webb captures a Penguin and an Egg for its two-year anniversary
This “penguin party” is loud! The distorted spiral galaxy at center, the Penguin, and the compact elliptical galaxy at left, the Egg, are locked in an active embrace. A new near- and mid-infrared image from the James Webb Space Telescope, taken to mark its second year of science, shows that their interaction is marked by a faint upside-down U-shaped blue glow.

This “penguin party” is loud! The distorted spiral galaxy at center, called the Penguin, and the compact elliptical galaxy at left, called the Egg, are locked in an active embrace. A new near- and mid-infrared image from the James Webb Space Telescope, taken to mark its second year of science, shows that their interaction is marked by a faint upside-down U-shaped blue glow. NASA, ESA, CSA, STScI

Today, July 12, marks two years since the first images from the James Webb Space Telescope were unveiled. In that time, Webb has discovered the most distant galaxies known, uncovered surprises about the early universe, peered into the atmospheres of distant planets, and produced a plethora of beautiful images of space.

Read more