  The presence of excesses of short-lived radionuclides in the early solar
system evidenced in meteorites has been taken as testament to close encounters
with exotic nucleosynthetic sources, including supernovae or AGB stars. An
analysis of the likelihoods associated with different sources of these extinct
nuclides in the early solar system indicates that rather than being exotic,
their abundances were typical of star-forming regions like those observed today
in the Galaxy. The radiochemistry of the early solar system is therefore
unexceptional, being the consequence of extensive averaging of molecular cloud
solids.
