In a remarkable turn of events, an amateur astronomer, Berto Monard from South Africa, observed a sudden brightening in a galaxy 76 million light-years away. The bright object, named SN 2022jli, appeared in the spiral arm of the galaxy NGC 157, and astronomers quickly honed in on the unusual sight. When a new, bright object appears in the sky, it often indicates a supernova, the explosive death of a star. Such events are exceedingly hard to study as they are unpredictable and fade quickly.

A supernova is a dramatic explosion caused when a massive star collapses under its own gravity. This collapse releases an intense burst of energy, sometimes illuminating the galaxy as brightly as billions of stars. This explosive end often produces either a neutron star or a black hole—extremely dense objects resulting from the core of the star compacting under gravitational forces. Yet, despite multiple supernova observations, scientists had never managed to directly link a supernova with the formation of these dense objects.

What made SN 2022jli stand out was its behavior. Initially bright, it began to dim and then, a month after discovery, it brightened again. Over the following 200 days, astronomers noticed a peculiar pattern of undulations occurring every 12 days. According to Thomas Moore from Queen’s University Belfast, these periodic oscillations, repeating over multiple cycles, had never been observed in a supernova before. These observations were published last year in the Astrophysical Journal.

The research teams, led by Ping Chen from the Weizmann Institute of Science, concluded that these periodic pulses likely came from the presence of a surviving companion star. This companion, although close to the exploding supernova, somehow withstood the blast and became instrumental in allowing astronomers to ‘see’ the newly formed compact object.

The hypothesis is that the black hole or neutron star produced in SN 2022jli’s collapse began pulling hydrogen from the companion’s atmosphere in a process called accretion. This accretion released energy in waves, which resulted in the oscillations detected by the astronomers. In their Nature paper, the researchers emphasized that the specific properties of SN 2022jli indicate that such a phenomenon is rare, likely due to the uncommon survival of a binary star system through a supernova explosion.

With SN 2022jli, scientists have built a direct link between supernova explosions and the birth of compact objects, marking the first time a potential black hole formation has been observed in real time. This finding is poised to shape future astronomical studies, offering an unprecedented look into one of the universe’s most mysterious transformations.

The unusual case of SN 2022jli has opened a new chapter in understanding supernovae and the lifecycle of stars. This firsthand observation of a supernova potentially transitioning into a black hole provides critical insights into these rare cosmic events. Although much remains to be discovered, this breakthrough represents a significant milestone in unraveling the mysteries of black holes and the violent ends of massive stars.