James Webb shows details of supernova remnant Cassiopeia A and rings around Uranus
NASA, ESA and the Canadian Space Agency CSA have published an image of Cassiopeia A, a supernova remnant. Also shown is a photo of planet Uranus with clearly visible rings. Both objects were imaged by the James Webb Space Telescope.
The image of Cassiopeia A was taken with the James Webb Space Telescope’s Mid-Infrared Instrument. Compared to previous infrared images, there are according to one researcher many more details visible that one did not have access to before. The colors are the result of infrared light that has been ‘translated’ into wavelengths from the visible part of the spectrum.
According to the space organizations, these colors lead to a wealth of scientific information. For example, on the outside, especially on the left and at the top, apparently red and orange material is visible, which is caused by the emission of warm dust. This is where the ejected material from the exploded star slams into the surrounding gas and dust. More on the inside, pink clogs and buttons are visible; this is material from the star that has started to radiate light through a mix of dust combined with heavy elements such as oxygen, argon and neon. The green has a shape and complexity that is unexpected for scientists and difficult to understand. Ilse De Looze of Ghent University, one of the researchers involved, says that they are still working to unravel all the sources of the emissions.
Cassiopeia A is about 10 light-years in size and is known as a supernova remnant located 11,000 light-years from Earth in the Cassiopeia constellation. It is the result of an explosion of a huge star whose light is estimated to have reached us about 340 years ago. It is the youngest known remnant of an explosion of a very large star in our galaxy. Cassiopeia A gives scientists the best opportunity to look at the remains of an exploded star and perform a kind of autopsy of a star to understand what type of star was there before and how it exploded.
The space agencies also have one image of Uranus published on which the difficult to see rings of the ice planet are visible. The planet’s faint dust rings have previously been captured only by the 1986 Voyager 2 spacecraft and Earth’s specially equipped William M. Keck Observatory. The current image of James Webb was taken with the telescope’s main camera, the NIRCam. This is an infrared image on which data from two filters at 1.4 and 3.0μm have been combined, which is shown in blue and orange respectively. Voyager 2 showed a blue-green ball in wavelengths in the visible spectrum with few features; in comparison, James Webb’s image contains much more detail. The telescope took the image on February 6.