Presolar grains: Interstellar Messengers to Study Hands-On Astrophysics

Presolar grains are bona-fide particles that originated in the ejecta and outflows of dying stars, travelled through the interstellar medium, and were incorporated into the first solids in the solar nebula 4.5 Ga ago. Today, we can find and extract these particles from unaltered meteorites. Each individual presolar grain recorded the nucleosynthetic fingerprint of its parent star, allowing us to study the conditions under which it condensed. While the majority of grains originated in asymptotic giant-branch stars, a smaller fraction condensed in the ejecta of core-collapse supernovae and some potentially even formed in the outflows of classical novae. These micrometer-sized grains allow us therefore to study a wide variety of astrophysical sites for stellar nucleosynthesis and galactic chemical evolution.In my talk, I will introduce the field of presolar grains analysis and present why these particles can be seen as an additional messenger in the larger picture of multi-messenger astronomy. The used, very sensitive, measurement techniques that allow us to analyze trace-element isotopic composition in these micrometer-sized particles will be introduced and limitations pointed out. Finally, I will present success stories of presolar grain studies and their application to astrophysical processes, e.g., to study the s-process, supernova ejecta, and galactic chemical evolution, and discuss future applications that only recently and with advancements in instrumentation became possible.