Astronomers say a star 730 million light-years away may have exploded while interacting with a black hole companion—and an AI system flagged the weird behavior early enough to watch the whole drama unfold.

Artist concept of a massive star distorted by a nearby black hole before the SN 2023zkd explosion — Artist’s conception of the massive star (blue) distorted by a nearby black hole before the explosion. Credit: Melissa Weiss / Center for Astrophysics | Harvard & Smithsonian (source).

Meet SN 2023zkd. First spotted by the Zwicky Transient Facility in July 2023, this supernova looked ordinary at first—until an AI system designed to find oddball light curves promoted it for follow-up. Months later, researchers realized the blast didn’t behave like typical supernovae: it showed a double-peaked light curve and, in archival data, a slow four-year brightening before the final detonation. That strange pre-game and the re-brightening after the blast point to a close-quarters interaction with a stellar-mass black hole nearby.