Objects in space reveal different aspects of their composition and behavior at different wavelengths of light. A supernova remnant called Cassiopeia A is one of the most studied objects in the Milky Way across the wavelength spectrum. However, there are still secrets hidden within the star’s tattered remains. The latest are being unlocked by the Near-Infrared Camera (NIRCam) instrument aboard the NASA/ESA/CSA James Webb Space Telescope.
Cassiopeia A is located about 11,000 light-years away from Earth in the constellation of Cassiopeia.
Also known as Cas A, SNR G111.7-02.1 or NRAO 711, the object 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 is one of the best-studied supernova remnants in all the cosmos.
Over the years, ground-based and space-based observatories, including the NASA/ESA Hubble Space Telescope, have collectively assembled a multiwavelength picture of the object’s tattered remains.
However, astronomers have now entered a new era in the study of Cassiopeia A.
In April 2023, Webb’s Mid-Infrared Instrument (MIRI) started this story, revealing new and unexpected features within the inner shell of the supernova remnant.
But many of those features are invisible in the new NIRCam image, and astronomers are investigating why that is.
“Infrared light is invisible to our eyes, so image processors and scientists represent these wavelengths of light with visible colors,” Webb astronomers said.
“In this newest image of Cassiopeia A, colors were assigned to NIRCam’s different filters, and each of those colors hints at different activity occurring within the object.”
“At first glance, the NIRCam image may appear less colorful than the MIRI image. However,…
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