Astronomers Observe Potential Birth of a Black Hole in Andromeda

Astronomers have identified a significant astronomical event in the Andromeda galaxy, approximately 2.5 million light-years from Earth. A yellow supergiant star, designated M31-2014-DS1, which is about twelve times the mass of the Sun, has seemingly vanished instead of undergoing a typical supernova explosion. This observation, led by Columbia University astrophysicist Kishalay De, suggests that the star may have collapsed into a black hole, marking it as the closest and best candidate for a newborn black hole ever observed.

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The investigation began in 2022 when De and his team utilized archival data from NASA’s Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) mission. They discovered that M31-2014-DS1 had brightened in 2014 before fading completely by 2022. The rarity of such failed supernovae is notable, with astronomers estimating a frequency of about once per century in large spiral galaxies. The team confirmed the star's unusual transition using data from various telescopes, including the Hubble Space Telescope.

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Following extensive computational modeling, De and his colleagues concluded that the failed supernova produced a black hole with a mass of approximately five solar masses, obscured by an ejected cloud of gas and dust. This model also aligns with previous observations of NGC 6946-BH1, another candidate for a failed supernova, although it is more challenging to study due to its greater distance. Christopher Kochanek, an astrophysicist not involved in De's study, acknowledged the new findings but raised concerns about the reliance on dust as an explanatory factor in astronomical observations.

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Despite the promising findings, the interpretation of M31-2014-DS1's disappearance is not universally accepted. Emma Beasor, an astrophysicist at Liverpool John Moores University, has proposed an alternative theory suggesting that both M31-2014-DS1 and NGC 6946-BH1 could be cases of stellar mergers rather than failed supernovae. Beasor emphasizes the need for clearer models to predict the characteristics of failed supernovae before confirming such events. Kochanek noted that distinguishing between a black hole and a stellar merger will ultimately depend on future observations, as a black hole will remain dark while a merger will continue to shine.

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The ongoing debate highlights the necessity for further observations to clarify the nature of these phenomena. Upcoming facilities, such as the Vera C. Rubin Observatory in Chile and NASA’s Nancy Grace Roman Space Telescope, are expected to enhance the search for similar events. Suvi Gezari, an astronomer at the University of Maryland, expressed optimism about the potential for discovering more candidates, which could help determine whether these events are predominantly failed supernovae, stellar mergers, or a combination of both.

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• “I got goosebumps when I saw it disappearing into darkness.” — Kishalay De, Astrophysicist

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• “But I’d argue we don’t have models yet that make very clear predictions about what they should look like.” — Emma Beasor, Astrophysicist

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• “Given those future capabilities, we can find more of these events to better determine if they’re all failed supernovae or stellar mergers or a mix,” — Suvi Gezari, Astronomer

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