Star attempts to swallow black hole, igniting one of the strangest supernovas ever seen

A star attempts to merge with a black hole, triggering a unique double supernova explosion.

: Astronomers discovered a supernova, named SN 2023zkd, which appears to have exploded twice, linked to a deadly encounter between a star and a black hole. Detected by the Zwicky Transient Facility in California in July 2023, this event was flagged by an AI system as it evolved unusually. Lead researcher Alexander Gagliano attributes the explosion to either a partial consumption of a black hole by the star or the black hole tearing it apart. Using AI, the team continues to explore such rare occurrences, enhancing our understanding of cosmic phenomena.

In July 2023, astronomers detected SN 2023zkd, a supernova about 730 million light-years away, which defied expectations by brightening a second time months after beginning to fade. This anomaly was flagged by an AI-driven detection system, prompting further investigation into its unusual light curve.

Archival observations revealed the star had been gradually brightening for four years before the explosion, a behavior inconsistent with typical supernovae that brighten rapidly and then dim. This suggested a complex pre-explosion process rather than a sudden catastrophic event.

Researchers proposed that the star was in a decaying orbit with a small black hole companion. As the orbit tightened, the black hole stripped gas and dust from the star, destabilizing it. Instead of being consumed, the star detonated in a gravitationally induced supernova.

The explosion produced two distinct peaks in brightness. The first occurred when the supernova shock wave collided with low-density gas surrounding the system. The second peak followed when the shock wave struck a denser, disk-shaped shell of material previously shed by the star.

This marks the first time scientists have captured such an event in full detail, from the years-long precursor phase to the multi-stage explosion. Future wide-field surveys like those from the Vera Rubin Observatory, combined with AI anomaly detection, may uncover more of these rare star–black hole interactions.

Sources: Washington Post, ScienceAlert, Gizmodo

SpacephysicsMachine Learning