- 1Riken, Center for Interdisciplinary Theoretical and Mathematical Sciences, Japan (ryo.sawada@riken.jp)
- 2The University of Tokyo, Department of Earth Science and Astronomy, Japan
- 3Kyoto University, Yukawa Institute for Theoretical Physics, Japan
- 4Kyoto University, Department of Astronomy, Japan
- 5Fukui Prefectural University, Center for Information Science, Japan
A key question in astronomy is how ubiquitous Earth-like rocky planets are. The formation of terrestrial planets in our Solar System was strongly influenced by the radioactive decay heat of short-lived radionuclides (SLRs), particularly 26Al (aluminum-26), likely delivered from nearby supernovae. However, current models struggle to reproduce the abundance of SLRs inferred from meteorite analysis without destroying the protosolar disk. We propose the "immersion" mechanism, where cosmic-ray nucleosynthesis in a supernova shockwave reproduces estimated SLR abundances at a supernova distance (~1 parsec), preserving the disk. We estimate that solar mass stars in star clusters typically experience at least one such supernova within 1 parsec, supporting the feasibility of this scenario. This suggests that Solar System─like SLR abundances and terrestrial planet formation are more common than previously thought.
How to cite: Sawada, R., Kurokawa, H., Suwa, Y., Taki, T., Lee, S.-H., and Tanikawa, A.: Cosmic-ray bath in a past supernova gives birth to Earth-like planets, Europlanet Science Congress 2026, The Hague, The Netherlands, 7–11 Sep 2026, EPSC2026-590, https://doi.org/10.5194/epsc2026-590, 2026.