Late formation of silicon carbide in type II supernovaeOPEN ACCESS 

Nan Liu, Larry R. Nittler, Conel M. O’D. Alexander and Jianhua Wang

Science Advances 17 Jan 2018:
Vol. 4, no. 1, eaao1054
DOI: 10.1126/sciadv.aao1054


“We have found that individual presolar silicon carbide (SiC) dust grains from supernovae show a positive correlation between 49Ti and 28Si excesses, which is attributed to the radioactive decay of the short-lived (t½ = 330 days) 49V to 49Ti in the inner highly 28Si-rich Si/S zone. The 49V-49Ti chronometer shows that these supernova SiC dust grains formed at least 2 years after their parent stars exploded. This result supports recent dust condensation calculations that predict a delayed formation of carbonaceous and SiC grains in supernovae. The astronomical observation of continuous buildup of dust in supernovae over several years can, therefore, be interpreted as a growing addition of C-rich dust to the dust reservoir in supernovae.”