Oxygen isotope anomalies of the Sun and the original environment of the solar system

Abstract

We present results from a model of oxygen isotopic anomaly production through selective photodissociation of CO within the collapsing proto-solar cloud. Our model produces a proto-Sun with a wide range of ∆17O values depending on the intensity of the ultraviolet radiation field. Dramatically different results from two recent solar wind oxygen isotope measurements indicate that a variety of compositions remain possible for the solar oxygen isotope composition. However, constrained by other measurements from comets and meteorites, our models imply the birth of the Sun in a stellar cluster with an enhanced radiation field and are therefore consistent with a supernova source for 60Fe in meteorites.