A new medium infrared image from the Webb Space Telescope shows it Supernova remnant Cassiopeia A (Cas A), which was formed 340 years ago by the explosion of a massive star. It is the youngest known remnant of a supernova explosion in our Milky Way galaxy.

Cas A has been observed extensively over the years using a variety of ground and space telescopes. By examining this object at different wavelengths, astronomers are trying to learn more about its properties.

For the Cas A image shown now, infrared light captured by Webb, which cannot be seen by the human eye, has been converted into visible light at different wavelengths. On the outside of the cosmic “bubble”—particularly at the top and left—are curtains of warm fabric appearing orange and red. These indicate where the exploding star collided with gas and dust in the environment.

Translucent light pink filaments can be seen within this outer shell, which appear as agglomerates. This is material from the star itself, which glows with a mixture of different heavy elements, such as oxygen, argon, and neon. The interstellar matter can also be seen as fainter tufts on the inside of the cavity.

One of the scientific questions that Cas A could help answer is where does cosmic dust come from. Observations have shown that even very small galaxies in the early universe contained huge amounts of dust. It is difficult to explain the origin of this dust without reference to supernovae, which blast large amounts of heavy elements (the building blocks of dust) into space.

However, current supernova observations fail to provide a definitive explanation for the amount of dust we see in those early galaxies. By studying Cas A more closely with Webb, astronomers hope to gain more insight into this object’s dust content. This can help us understand where the materials that make us and the planets come from.

Cas A is about ten light-years across and is located 11,000 light-years away in the constellation Cassiopeia. (EE)

Webb reveals never-before-seen details of Cassiopeia A.