Overview

• The circumstellar bubble contains as much mass as the Sun and spans 1.4 light years around DFK 52 in the Stephenson 2 cluster.
• ALMA observations traced gas velocities that indicate the material was expelled in a powerful eruption roughly 4,000 years ago.
• Detailed imaging uncovered tangled filaments, nested loops and a ring-like bar preserved in cooled molecules such as CO and SiO.
• The solar-mass scale and expansion dynamics contradict theories of steady, low-rate winds in the final stages of red supergiants.
• Researchers led by Mark Siebert and Elvire De Beck plan follow-up observations to search for a hidden companion star and refine pre-supernova mass-loss models.