The Early-Solar System soon after condensation hosted radioactive nuclides which are since extinct. Similar nuclides, constantly fed by matter ejected from stars in their various phases, are now directly observed in the Galaxy by gamma-ray astronomy. Laboratory studies and new techniques allow us to measure the yield of nuclear reactions producing some of these nuclides in the energy regime of nucleosynthesis and, with the aid of stellar models, to compare them with astronomical observations. The fascinating challenge of investigating directly the composition of interstellar matter through grains penetrating the Solar System, has recently begun to be addressed. The presence of live radioactive nucleosynthesis products can serve in this case as an identification signature. Experimental techniques developed for that purpose will be described.

ANL Physics Division Colloquium Schedule