New data detects potassium and chlorine in Cassiopeia supernova remnant
Using the Japanese orbiting XRISM space telescope, astronomers have now detected evidence of both potassium and chlorine in the ancient Cassiopeia supernova remnant.
The picture to the right, reduced to post here, shows the evidence for potassium in the remnant, overlaid onto an image of Cassiopeia produced by combining data from X-ray data from Chandra, infrared data from Webb, and optical data from Hubble. The green grid boxes indicate strong evidence of potassium, while the yellow grid boxes indicate weaker evidence.
The roughly circular Cas A supernova remnant spans about 10 light-years, is over 340 years old, and has a superdense neutron star at its center — the remains of the original star’s core. Scientists using NASA’s Chandra X-ray Observatory had previously identified signatures of iron, silicon, sulfur, and other elements within Cas A.
In the hunt for other elements, the team used the Resolve instrument aboard XRISM to look at the remnant twice in December 2023. The researchers were able to pick out the signatures for chlorine and potassium, determining that the remnant contains ratios much higher than expected. Resolve also detected a possible indication of phosphorous, which was previously discovered in Cas A by infrared missions.
The orientation and position of these grid boxes on the face of the expanding supernova remnant suggest the original star and explosion might have formed unevenly.
Using the Japanese orbiting XRISM space telescope, astronomers have now detected evidence of both potassium and chlorine in the ancient Cassiopeia supernova remnant.
The picture to the right, reduced to post here, shows the evidence for potassium in the remnant, overlaid onto an image of Cassiopeia produced by combining data from X-ray data from Chandra, infrared data from Webb, and optical data from Hubble. The green grid boxes indicate strong evidence of potassium, while the yellow grid boxes indicate weaker evidence.
The roughly circular Cas A supernova remnant spans about 10 light-years, is over 340 years old, and has a superdense neutron star at its center — the remains of the original star’s core. Scientists using NASA’s Chandra X-ray Observatory had previously identified signatures of iron, silicon, sulfur, and other elements within Cas A.
In the hunt for other elements, the team used the Resolve instrument aboard XRISM to look at the remnant twice in December 2023. The researchers were able to pick out the signatures for chlorine and potassium, determining that the remnant contains ratios much higher than expected. Resolve also detected a possible indication of phosphorous, which was previously discovered in Cas A by infrared missions.
The orientation and position of these grid boxes on the face of the expanding supernova remnant suggest the original star and explosion might have formed unevenly.












