Dust still lingers in the leftovers of a supernova that exploded thousands of years ago. Its existence demonstrates that the material can survive the reverse shock waves of stellar explosions, researchers report online March 19 in Science.
Ryan Lau of Cornell University and fellow astronomers found the lingering dust in Sagittarius A East, a remnant of a supernova 26,000 light-years away that exploded (from an Earth-based viewpoint) 10,000 years ago.
Past observations have shown that the initial explosive shock wave of a supernova can create dust (SN: 2/8/14, p. 7; SN Online 7/9/14). What has been unclear, however, is whether supernova dust can survive reverse shock waves, which occur roughly 1,000 years after a stellar explosion.
Based on infrared images,Lau and colleagues estimate that 10 to 20 percent of the initial dust made in supernova Sagittarius A East survived the reverse shock wave of the explosion. A similar amount of dust — and possibly more — may have survived supernovas in the early universe. That dust provided the raw materials for bursts of star and planet formation to begin billions of years ago, Lau says.