Astronomers watch a massive star collapse into a black hole without a supernova

Astronomers have observed a massive star in the Andromeda Galaxy collapse directly into a black hole without undergoing a supernova explosion. The star, designated M31-2014-DS1 and located approximately 2.5 million light-years away, gradually faded over several years before disappearing from visible and near-infrared light. Instead of a dramatic explosion, the star’s core succumbed to gravity, forming a black hole while its outer layers were slowly expelled, leaving behind glowing debris detectable in mid-infrared wavelengths. This event marks the most detailed observation to date of a star transitioning into a black hole without a supernova, providing valuable insights into the final stages of massive stars. Researchers analyzed data spanning nearly two decades from NASA’s NEOWISE mission and other telescopes, noting the star’s infrared brightening in 2014 followed by a rapid decline in brightness by 2016. By 2023, the star had faded to a fraction of its original brightness, with only the dust and gas surrounding the newborn black hole emitting detectable infrared light. The findings challenge conventional understanding that massive stars end their lives primarily through explosive supernovae, suggesting that some may quietly collapse instead. This discovery helps explain the diversity in stellar deaths and black hole formation, offering a new benchmark for studying these processes. The lingering infrared glow from the debris is expected to remain visible for decades with sensitive instruments like the James Webb Space Telescope, allowing astronomers to monitor the black hole’s birth and evolution over time. Lead author Kishalay De of the Simons Foundation’s Flatiron Institute emphasized that this observation is just the beginning of a deeper exploration into how stellar black holes form. The study, published in Science, opens new avenues for understanding the life cycles of the universe’s most massive stars and the mechanisms behind their ultimate fate.