Extinct 44Ti in Presolar Graphite and SiC: Proof of a Supernova Origin
Abstract
Large excesses in 44Ca, from the radioactive decay of short-lived 44Ti, have been observed in four low-density graphite grains and five SiC grains of type X extracted from the Murchison meteorite. Titanium-46, 49Ti, and 50Ti excesses were also observed in several of these grains. Because 44Ti is only produced in supernovae, these grains must have a supernova origin. Moreover, Si-, C-, N-, Al-, O-, and Ti-isotopic compositions of the grains require a Type II supernova source, and indicate extensive and heterogeneous mixing of different supernova regions, including the nickel core.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1996
- DOI:
- 10.1086/310021
- Bibcode:
- 1996ApJ...462L..31N
- Keywords:
-
- NUCLEAR REACTIONS;
- NUCLEOSYNTHESIS;
- ABUNDANCES;
- STARS: SUPERNOVAE: GENERAL;
- ISM: DUST;
- EXTINCTION