Short-lived radionuclides were present in the solar protoplanetary disk in abundances much higher than in the ambient interstellar medium and require a last minute origin. Al-26 (T-1/2 = 0.73 Myr) and Ca-41 (T-1/2 = 0.1 Myr) abundances in the protoplanetary disk constrain models for the origin of short-lived radionuclides because they share a common origin. It is usually assumed that these isotopes were injected into the disk from a nearby Type II supernova. Here we show that the oxygen isotopic composition of the protoplanetary disk would have shifted by several percent relative to the Sun as a result of such injection. Therefore, the supernova injection model will be tested by the anticipated measurement of the solar wind oxygen isotopic composition from the Genesis sample return mission.
Frédéric Courbin, Martin Raoul Robert Millon