2017/12/20 by Vikram V. Dwarkadas, Nicolas Dauphas, Bradley Meyer +4 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Astrobiology #Astronomy #Astrophysics #Bubble #Formation and evolution of the Solar System #Gamma-ray bursts and supernovae #Materials science #Mechanics #Physics #Shell (structure) #Solar System #Star formation #Stars #Stellar, planetary, and galactic studies #Supernova #Wolf–Rayet star #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aa992e
published as Astrophysical Journal, 2017, Vol 851, 147 · 19 pages, 6 figures. Accepted version. Final published version with proof corrections can be found on the Astrophysical Journal web page for ApJ, 2017, 851, 147
openalex publication_date 2017/12/20 · arxiv created 2017/12/28 · arxiv updated 2018/01/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A critical constraint on solar system formation is the high 26Al/27Al abundance ratio of 5 × 10-5 at the time of formation, which was about 17 times higher than the average Galactic ratio, while the 60Fe/56Fe value was about 2 × 10-8, lower than the Galactic value. This challenges the assumption that a nearby supernova was responsible for the injection of these short-lived radionuclides into the early solar system. We show that this conundrum can be resolved if the Solar System was formed by triggered star formation at the edge of a Wolf-Rayet (W-R) bubble. Aluminium-26 is produced during the evolution of the massive star, released in the wind during the W-R phase, and condenses into dust grains that are seen around W-R stars. The dust grains survive passage through the reverse shock and the low density shocked wind, reach the dense shell swept-up by the bubble, detach from the decelerated wind and are injected into the shell. Some portions of this shell subsequently collapses to form the dense cores that give rise to solar-type systems. The subsequent aspherical supernova does not inject appreciable amounts of 60Fe into the proto-solar-system, thus accounting for the observed low abundance of 60Fe. We discuss the details of various processes within the model and conclude that it is a viable model that can explain the initial abundances of 26Al and 60Fe. We estimate that 1-16% of all Sun-like stars could have formed in such a setting of triggered star formation in the shell of a WR bubble.