Nasa just mapped the corpse of a giant exploded star

Sign up to our free weekly IndyTech newsletter delivered straight to your inbox Sign up to our free IndyTech newsletter Sign up to our free IndyTech newsletter SIGN UP I would like to be emailed about offers, events and updates from The Independent. Nasa’s Imaging X-ray Polarimetry Explorer or IXPE, launched in 2021 in collaboration with the Italian Space Agency, trained its sensitive polarised X-ray instruments on Cassiopeia A, or Cas A, a glowing cloud of gas left over by a massive star that went supernova in the late 17th century. Powerful magnetic fields in Cas A trap high energy particles, accelerate them to nearly the speed of light, and generate powerful radiation, emitting polarised X-rays, that is X-ray waves that oscillate in one direction, relative to the magnetic field that generated that wave. The IXPE results show that X-rays originate from magnetic fields mostly aligned with, rather than perpendicular to, other magnetic fields that produce radio waves in Cas A, and that the magnetic fields around the edges of the 10-light-year-diameter Cas A are oriented radially, pointing outward from the centre. “The fact that a smaller percentage of the X-ray light is polarised is a very interesting – and previously undetected – property of Cas A.” The Cas A observations are just the first of many more IXPE investigations into the properties of supernova remnants, an opportunity to open a window into the strange, high-energy physics of the afterglows of some of the largest explosions the universe has ever seen.