Dominant formation pathway for actinides

Determine the dominant astrophysical pathway responsible for actinide production among proposed sites that include neutron star mergers, black hole–neutron star mergers, and magneto-rotational supernovae.

Background

Several candidate sites—neutron star mergers, black hole–neutron star mergers, and magneto-rotational supernovae—have been proposed to produce actinides. Actinide-boost stars indicate extreme conditions in the r-process, but current evidence does not uniquely identify which site predominantly forms actinides. Clarifying the dominant pathway is essential for interpreting actinide-boost abundance patterns and for constraining nucleosynthesis models.

References

Although NSMs, BH-NSMs, and MR-SNe have been proposed as potential sources of actinide production, the dominant formation pathway for actinides remains unclear.

— The Actinide-Boost Star LAMOST J122216.85-063345.2: A Detailed R-process Abundance Study with Gemini-S/GHOST  (2603.29246 - Jeong et al., 31 Mar 2026) in Section 1, Introduction