Astronomers have spotted an unusual supernova event, SN 2023zkd, that offers insights into the catastrophic interaction between a black hole and a massive star. The event was discovered in July 2023 by the Zwicky Transient Facility and quickly followed up by telescopes using an artificial intelligence algorithm.
The standard behavior of supernovae is for them to brighten initially before fading over months. However, SN 2023zkd’s unusual brightness pattern, which included a second peak several months after the initial explosion, led researchers to investigate the involvement of a black hole.
According to the study, either a star with over 30 times the mass of our Sun was orbiting a stellar-size black hole or the black hole ripped apart the star before engulfing it. In both scenarios, the result is an even more massive black hole.
Lead author Alexander Gagliano noted that the event provides strong evidence for catastrophic encounters between close binary companions triggering supernovae. The machine learning system’s early detection allowed researchers to secure critical observations needed to unravel the explosion.
Archival observations before the supernova revealed a star brightening over four years, releasing material into two shells of different densities. These shells interacted after the explosion, igniting and causing the second peak in activity.
The study highlights the importance of artificial intelligence algorithms in discovering rare events as they happen, not just after the fact. This will enable astronomers to connect the dots between a star’s life and death, offering new insights into stellar evolution.
The event occurred in a galaxy 730 million light-years from Earth and has been published in The Astrophysical Journal.
Source: https://www.iflscience.com/a-black-hole-hitting-a-star-created-a-never-before-seen-supernova-80403