The explosion of a star is a dramatic event, but the remnants left behind by the star can be even more dramatic. A new mid-infrared image from NASA's James Webb Space Telescope provides a striking example. It shows Cassiopeia A (Cas A) from Earth's point of view, the supernova remnant created by a star explosion 340 years ago. Cas A is the youngest known remnant of a massive star that exploded in our galaxy, making it a unique opportunity to learn more about how such supernovas form.

"Cas A represents our best opportunity to do some kind of stellar autopsy to look at the debris field of an exploded star and figure out what kind of star was there before and how that star exploded," said Danny Milisavljevic of Purdue University in West Lafayette. . Indiana is the principal investigator for the Webb program that recorded these observations.

"Compared to previous infrared images, we're seeing incredible detail that we weren't able to access before," added Tea Temim of Princeton University in Princeton, New Jersey, one of the program's researchers.

Cassiopeia A is a prototypical supernova remnant that has been widely studied by a number of ground-based and space-based observatories, including NASA's Chandra X-ray Observatory. Multiple wavelength observations can be combined to give scientists a more comprehensive understanding of the residue.

EXAMINATION OF THE IMAGE

The striking colors of the new Cas A image, in which infrared light is converted into visible light wavelengths, hold a wealth of scientific information the team is just beginning to uncover. On the outside of the balloon, especially on the top and left, there are curtains of material that appear orange and red due to the emission of warm dust. This marks where the material ejected from the exploded star collided with the surrounding extrastellar gas and dust.

The inner part of this outer bark contains bright pink mottled fibers adorned with clumps and knots. This represents material from the star itself, which glows due to the mixture of various heavy elements such as oxygen, argon and neon, as well as dust emission.

"We're still trying to figure out all these emission sources," said Ilse De Looze of the University of Ghent in Belgium, another researcher in the program.

Star material can also be seen as fainter tufts near the interior of the cavity.

Perhaps most prominently, a ring represented by green runs along the right side of the central cavity. “We named him the Green Monster in honor of Fenway Park in Boston. If you look closely, you'll notice that it's full of what looks like mini-bubbles,” said Milisavljevic. "The shape and complexity are unexpected and difficult to understand."

THE ORIGINS OF COSMIC DUST AND US

Science questions Cas A can help answer include: Where does cosmic dust come from? Observations have found that even very young galaxies in the early universe are covered with large amounts of dust. The origin of this dust is difficult to explain without resorting to supernovae, which spewed large quantities of heavy elements (the building blocks of dust) into space.

However, current supernova observations cannot definitively explain the amount of dust we see in these early galaxies. By studying Cas A with Webb, astronomers hope to better understand its dust content that could aid our understanding of where the building blocks of planets and ourselves were created.

"In Cas A, we can spatially resolve regions with different gas compositions and look at what types of dust are forming in these regions," said Temim.

The supernovae that make up Cas A are crucial to life as we know it. By spreading elements like calcium in our bones and iron in our blood into interstellar space, they seeded a new generation of stars and planets.

"By understanding the starburst process, we read our own origin story," said Milisavljevic. "I'll spend the rest of my career trying to figure out what's going on in this dataset."

Cas A remnant is about 10 light-years across and is located 11,000 light-years away in the constellation Cassiopeia.

The James Webb Space Telescope is the world's leading space science observatory. Webb will unravel mysteries in our solar system, look beyond distant worlds around other stars, and explore the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners ESA (European Space Agency) and the Canadian Space Agency.

 

See also the mythological story of Cassioope

 

Source: https://www.nasa.gov/