A new mid-infrared image from the Mid-Infrared Instrument (MIRI) onboard the NASA/ESA/CSA James Webb Space Telescope shows the supernova remnant Cassiopeia A, created by a stellar explosion more than 11,000 years ago.
This new image from Webb’s Mid-Infrared Instrument (MIRI) shows Cassiopeia A, a supernova remnant located about 11,000 light-years from Earth in the constellation Cassiopeia. Image credit: NASA / ESA / CSA / D.D. Milisavljevic, Purdue University / T. Temim, Princeton University / I. De Looze, Ghent University / J. DePasquale, STScI.
Cassiopeia A, which is located about 11,000 light-years away from Earth in the constellation of Cassiopeia, is the most studied nearby supernova remnant.
Also known as Cas A, SNR G111.7-02.1 or NRAO 711, the remnant spans approximately 10 light-years.
When the original star ran out of fuel, it collapsed onto itself and blew up as a supernova, possibly briefly becoming one of the brightest objects in the sky.
Although astronomers think that this happened around the year 1680, there are no verifiable historical records to confirm this.
Cassiopeia A has been widely studied by a number of ground-based and space-based observatories, including NASA’s Chandra X-ray Observatory.
The multi-wavelength observations can be combined to provide astronomers with a more comprehensive understanding of the remnant.
“Cassiopeia 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 Dr. Danny Milisavljevic, an astronomer at Purdue University.
“Compared to previous infrared images, we see incredible detail that we haven’t been able to access before,” added Dr. Tea Temim, an astronomer at Princeton University.
The striking colors of the new image of Cassiopeia A hold a wealth of scientific information the astronomers are just beginning to tease out.
On the bubble’s exterior, particularly at the top and left, lie curtains of material appearing orange and red due to emission from warm dust.
This marks where ejected material from the exploded star is ramming into surrounding circumstellar gas and dust.
Interior to this outer shell lie mottled filaments of bright pink studded with clumps and knots.
This represents material from the star itself, which is shining due to a mix of various heavy elements, such as oxygen, argon, and neon, as well as dust emission.
“We’re still trying to disentangle all these sources of emission,” said Dr. Ilse De Looze, an astronomer at Ghent University.
“The stellar material can also be seen as fainter wisps near the cavity’s interior.”
“Perhaps most prominently, a loop represented in green extends across the right side of the central cavity.”
By studying Cassiopeia A with Webb, the researchers hope to gain a better understanding of its dust content, which can help inform our understanding of where the building blocks of planets and ourselves are created.
“In Cassiopeia A, we can spatially resolve regions that have different gas compositions and look at what types of dust were formed in those regions,” Dr. Temim said.
“Supernovae like the one that formed Cassiopeia A are crucial for life as we know it.”
“They spread elements like the calcium we find in our bones and the iron in our blood across interstellar space, seeding new generations of stars and planets.”
“By understanding the process of exploding stars, we’re reading our own origin story,” Dr. Milisavljevic said.
“I’m going to spend the rest of my career trying to understand what’s in this data set.”
