NASA’s Webb Telescope Reveals Supernova in Unprecedented Detail

The most powerful space observatory in history just captured a gorgeous and unprecedented glimpse of a supernova remnant, exposing the messy leftovers of an enormous star that died in a brilliant explosion. 

The newest image from NASA’s next-generation James Webb Space Telescope (JWST) reveals the swirling remnant known as Cassiopeia A (Cas A) like it has never been seen before, according to a NASA statement. Located about 11,000 light years from Earth, Cas A is a massive bubble of gas and dust that was created when a massive star blew up. 

“Cas A represents our best opportunity to look at the debris field of an exploded star and run a kind of stellar autopsy to understand what type of star was there beforehand and how that star exploded,” said Danny Milisavljevic, an astronomer at Purdue University and a member of the JWST team, in the statement.

The sky is littered with the remains of many exploded stars, but Cas A is special because it is the youngest known remnant in the Milky Way, from our perspective here on Earth. Light from the supernova probably arrived at our planet about 340 years ago, in the 1690s, and its spectacular aftermath has been imaged countless times by sophisticated telescopes.

However, the new infrared observations from JWST bring Cas A into sharper focus than ever before. The colors in the above image have been adjusted into visible wavelengths, but the various hues represent real phenomena occurring within this epic structure, which stretches across 10 light years in the constellation Cassiopeia. The new features captured by JWST include a green loop near the center of the remnant that the team dubbed the “Green Monster” in honor of the huge left field wall at Fenway Park in Boston, which shares this nickname. 

“If you look closely, you’ll notice that it’s pockmarked with what look like mini-bubbles,” said Milisavljevic. “The shape and complexity are unexpected and challenging to understand.”

In addition to helping scientists understand the lives and deaths of stars, these kinds of observations can shed light on the emergence of life on Earth, and its possible existence on other worlds. This is because important elements for life—such as carbon, nitrogen, and heavy metals—are forged in the bellies of stars. When stars die, these materials get spewed back out into space where they seed new planetary systems with the ingredients for life. 

“By understanding the process of exploding stars, we’re reading our own origin story,” concluded Milisavljevic. “I’m going to spend the rest of my career trying to understand what’s in this data set.”

Perhaps most prominently, a loop represented in green extends across the right side of the central cavity. “We’ve nicknamed it the Green Monster in honor of Fenway Park in Boston. If you look closely, you’ll notice that it’s pockmarked with what look like mini-bubbles,” said Milisavljevic. “The shape and complexity are unexpected and challenging to understand.”

“By understanding the process of exploding stars, we’re reading our own origin story,” said Milisavljevic. “I’m going to spend the rest of my career trying to understand what’s in this data set.”