Artist’s impression of the shock wave from a supernova colliding with the filaments of the molecular cloud where the Sun is forming. 1 credit
Evidence from isotopic ratios in meteorites indicates that the supernova explosion occurred nearby when our sun and solar system were still in their formative stages. The explosion from this supernova could destroy the nascent solar system.
New calculations reveal that filaments of molecular gas, the birth cocoon of our solar system, played an important role in trapping isotopes discovered in meteorites. At the same time, this thread served as a shield, protecting the nascent solar system from the destructive forces of a nearby supernova explosion.
Early meteorites retain information about conditions when the sun and planets were born. The meteorite components show an inhomogeneous concentration of the radioactive isotope of aluminum.
This difference indicates that additional radioactive aluminum was introduced shortly after the formation of the solar system began. A nearby supernova explosion is the best candidate for this injection of new radioisotopes.
But a supernova close enough to deliver the amount of isotopes visible in meteorites would also have created a shock wave powerful enough to rip apart the nascent solar system.
A team led by Doris Arzumanian at the National Astronomical Observatory of Japan has provided a new explanation for how the solar system acquired the amount of isotopes measured in meteorites while surviving the shock of a supernova. Stars form in large groups called clusters within giant clouds of molecular gas.
These molecular clouds are filamentous. Small stars like the Sun usually form along filaments and larger stars, which explode into supernovae, usually form in hubs where multiple filaments intersect.
Assuming that the sun formed along a dense filament of molecular gas and a supernova exploded in the close center of the filaments, the team’s calculations showed that it would take at least 300,000 years for the shock wave to break through the dense filaments around the forming solar system.
The isotope-enriched meteorite components formed during the first 100,000 years or so of the solar system’s formation within the dense filament. The parent filament may have acted as a barrier to protect the young sun and helped capture radioactive isotopes from the supernova’s shock wave and divert them to the still-forming solar system.
Reference: “Insights on the Sun’s Birth Environment in the Context of Star Cluster Formation in Hub-Filament Systems” by Doris Arzumanian, Sota Arakawa, Masato N. Kobayashi, Kazunari Iwasaki, Kohei Fukuda, Shoji Mori, Yutaka Hirai, Masanobu Kunetomo, MS Nanda Kumar and Ichiro Kokobo, April 25, 2023, Available here. The Astrophysical Journal Letters.
DOI: 10.3847 / 2041-8213 / acc849
