Remains of a rare supernova discovered inside a meteorite

Scientists at Curtin University in Australia discovered rare dust left behind from a supernova explosion inside a meteorite. The discovery is reported in the article, published в The Astrophysical Journal.

Researchers used a technique called atom probe tomography to analyze dust particles inside a sample of the ALH 77307 meteorite discovered in Antarctica. This carbonaceous chondrite is a primitive meteorite, meaning it formed from interstellar material, and contains presolar grains—mineral particles that arose from the cooling gas of earlier stars.

One of the particles had an extremely unusual ratio of the isotopes magnesium-25 and magnesium-24. Until now, the most extreme deviation of the 25Mg/24Mg isotope signature from the standard sample of presolar grains was 1200 ppm, but this time the deviation was a record 3025 ppm.

This high abundance of magnesium-25 isotopes compared to other stable magnesium isotopes challenges current stellar models, the researchers write. The most plausible scenario for their origin is a supernova of an unusual type, characterized by the explosive combustion of hydrogen.