Caught in the act: Astronomers watch a vanishing star turn into a black hole
Peer-Reviewed Publication
Updates every hour. Last Updated: 27-Apr-2026 21:15 ET (28-Apr-2026 01:15 GMT/UTC)
A team of astronomers led by the Flatiron Institute’s Kishalay De discovered that a star in the Andromeda Galaxy disappeared without going supernova, and instead collapsed directly into a black hole. The team’s analysis of the star, reported in Science, reveals what happened and helps explain why some massive stars turn into black holes while others don’t.
Astronomers have caught a massive star in the Andromeda Galaxy quietly dying, collapsing into a black hole without producing a supernova, leaving behind little more than a fading trace. The findings provide some of the strongest evidence yet that so-called “failed supernovae” can produce stellar-mass black holes. Near the end of their lives, massive stars can become unstable and swell in size, producing noticeable changes in brightness over timescales humans can observe. In many cases, these stars die in brilliant supernovae, which are extremely luminous and easy to detect. However, not all dying stars explode. Theory suggests that some massive stars fail to produce a successful explosion. Instead, when the star’s core collapses, its outer material falls back inward, forming a black hole. Yet such failed supernovae are difficult to detect because they emit weak energy signatures and appear mainly as stars that simply vanish from view. Using archival, long-term infrared observations from the NEOWISE space mission, Kishalay De and colleagues searched for variable stars in the nearby Andromeda galaxy and discovered an unusual stellar object that briefly brightened but then steadily faded. According to the authors, this star, known as M31-2014-DS1, increased in infrared brightness over roughly two years starting in 2014, but then dimmed and eventually became nearly invisible in optical light by 2022, effectively disappearing. Follow-up observations with Hubble and large ground-based telescopes revealed only a very faint, red remnant detectible in the near-infrared, suggesting the star is now heavily shrouded in dust – a mere shadow of the luminous supergiant it had been just years before. De et al. interpret these observations as evidence for a failed supernova leading to the birth of a stellar-mass black hole.
Podcast: A segment of Science's weekly podcast with Kishalay De, related to this research, will be available on the Science.org podcast landing page [http://www.science.org/podcasts] after the embargo lifts. Reporters are free to make use of the segments for broadcast purposes and/or quote from them – with appropriate attribution (i.e., cite "Science podcast"). Please note that the file itself should not be posted to any other Web site.
The star, in the Andromeda galaxy, collapsed and disappeared without first exploding in a supernova.
Researchers at Oxford University and the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) are proposing a new way to observe tightly bound supermassive black hole binaries. Formed naturally when galaxies merge, only widely separated systems have confidently been observed to date. In a paper published today in Physical Review Letters, the researchers suggest hunting down the hidden systems by searching for repeating flashes of light from individual stars lying behind the black holes as they are temporarily magnified by gravitational lensing as the binary orbits.
Recent experiments on twisted MoTe2 have observed the fractional quantum anomalous Hall effect in the absence of an external magnetic field. Now, a theoretical study employing a real-space lattice model and precision many-body calculations presents a comprehensive ground-state phase diagram and elucidates the finite-temperature and dynamical behaviors of the system. The work reveals competing phases, including fractional Chern insulators and quantum anomalous Hall crystals, and identifies experimentally testable energy scales.
One of the longest stellar dimming events ever observed was likely caused by the gigantic saucer-like rings of either an unseen brown dwarf or 'super-Jupiter' blocking its host star's light, astronomers say. For decades the star – which sits 3,200 light-years from Earth and is about twice as big as our Sun – had been observed as stable, but at the end of 2024 it faded dramatically. It then remained this way for more than nine months, far longer than is normal for an event like this, sparking confusion among researchers and prompting speculation as to what could have caused such an "extremely rare" phenomenon. Now, in a new study published today in Monthly Notices of the Royal Astronomical Society, a team of international researchers believe they may have solved the riddle of this mysterious star in the Monoceros constellation.
If a gas giant planet is big enough to ignite deuterium fusion, it becomes a brown dwarf instead of a planet. But this definition is incomplete and does not tell us how gas giants form or what material they accreted. UCLA and UCSD astronomers have detected hydrogen sulfide gas in the atmospheres of four distant gas giants. The sulfur had to have come from evaporated solid matter from the disk around the star, proving that they are, indeed, planets. The new method used to detect the gas will be useful for studying exoplanets far from Earth in clear detail and to eventually identify Earth-like exoplanets.
A team of researchers have used spectral data from NASA's James Webb Space Telescope (JWST) to probe the HR 8799 star system and show that one of its giant Jupiter-like planets contains sulfur, a sign it formed like a planet not a star.