A Needle in a Haystack - Searching for Stardust inside the Solar System
Event date
Pierre Haenecour
University of Arizona
N232 103
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Tiny specks of dust remaining grains condensed in the ‘envelopes’ around stars or in material ejected by certain stellar explosions (e.g., core-collapse supernovae or novae) before the Solar System formed. Although most of the original dust grains were destroyed in the early stages of Solar System formation, a small portion, called presolar grains or stardust, remained intact inside asteroids and comets, and can be found today in the fine-grained material of primitive extraterrestrial samples, such as meteorites. These presolar grains constitute the only remnants of its original building blocks. The characterization of the isotopic and elemental compositions of presolar grains opened a new field in Astronomy and Astrophysics, allowing the direct in-situ laboratory study of individual stars and providing ground-truth information on nucleosynthetic processes and grain condensation in circumstellar envelopes, as well as secondary processes (heating or aqueous alteration) in the early solar system history. I will introduce presolar grains and present two case-study examples of (1) how coordinated laboratory analysis of these specks of dust provide constraints on their parent stars and formation histories, and (2) how the abundance and composition of presolar grains in unequilibrated planetary material can be used as tracers of both nebular and parent-body processes that occurred during the early stages of our solar system history.