Astronomical Oxygen Isotopic Evidence for Supernova Enrichment of the Solar System Birth Environment by Propagating Star Formation

TL;DR

This study provides evidence that the solar system's oxygen isotope ratios were enriched by supernova ejecta from nearby star formation, suggesting a supernova contribution to the solar system's birth environment.

Contribution

It demonstrates that the solar system's oxygen isotope anomaly is best explained by 1% enrichment from supernovae in a propagating star formation region.

Findings

Solar oxygen isotope ratios are higher than in other galactic regions.

Enrichment likely occurred from supernovae of B stars 10-20 million years before Sun formation.

Infrared measurements confirm local supernova influence on solar system material.

Abstract

New infrared absorption measurements of oxygen isotope ratios in CO gas from individual young stellar objects confirm that the solar system is anomalously high in its 18O/17O ratio compared with extra-solar oxygen in the Galaxy. We show that this difference in oxygen isotope ratios is best explained by 1 per cent enrichment of the proto-solar molecular cloud by ejecta from type II supernovae from a cluster having of order a few hundred stars that predated the Sun by at least 10 to 20 Myr. The likely source of exogenous oxygen was the explosion of one or more B stars during a process of propagating star formation.