Presolar grains

<p>Presolar grains are interstellar solid matter in the form of tiny solid grains that originated at a time before the <a href="/facts/Sun/CadPCVHh">Sun</a> was formed. Presolar grains formed within outflowing and cooling gases from earlier presolar stars. The study of presolar grains is typically considered part of the field of <a href="/facts/Cosmochemistry/dWzNMp2x">cosmochemistry</a> and <a href="/facts/Meteoritics/8foYPk51">meteoritics</a>.
</p><p>The <a href="/facts/Stellar_nucleosynthesis/qEQJdJe6">stellar nucleosynthesis</a> that took place within each presolar star gives to each granule an <a href="/facts/Isotopes/KD9B1y6o">isotopic</a> composition unique to that parent star, which differs from the isotopic composition of the <a href="/facts/Solar_System/QIcLSazQ">Solar System</a>'s matter as well as from the galactic average. These <a href="/facts/Isotopic_signature/fE1gX6nH">isotopic signatures</a> often fingerprint very specific astrophysical nuclear processes that took place within the parent star or formation event and prove their presolar origin.
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Presolar grains open-in-new

Presolar grains