Overview

• A study by the Center for Astrophysics | Harvard & Smithsonian and MIT published in The Astrophysical Journal confirms SN 2023zkd’s double-peaked light curve and four-year precursory brightening as evidence of dense circumstellar material.
• Scientists attribute the two light-curve peaks to the supernova’s blast wave colliding first with low-density gas and later with a thicker, disk-like shell ejected during prior black hole–star interactions.
• The analysis interprets gravitational stress from a compact black hole companion as the likely trigger for the explosion while acknowledging alternative scenarios such as partial tidal disruption remain viable.
• A machine-learning alert flagged SN 2023zkd’s surprising rebrightening roughly 240 days after its July 2023 detection by ZTF, enabling swift Swift, Pan-STARRS and ground-based follow-up to trace its multi-year evolution.
• Researchers say the event points to a hidden class of black hole–induced transients and urge AI-driven surveys and advanced theoretical modeling with facilities like the Vera C. Rubin Observatory to identify more.