At a Glance
- Astronomers confirmed the existence of a lone black hole, previously unseen, through collaboration between the Space Telescope Science Institute, the University of St Andrews, and the European Southern Observatory.
- The black hole, spotted in 2011 and observed from 2011 to 2017 with the Hubble Space Telescope, was further analyzed using Hubble and Gaia space probe data, revealing it has seven times the mass of our sun.
- The object was confirmed to be a black hole after it caused light from a distant star to magnify and shift, ruling out the possibility of it being a neutron star.
- Unlike known black holes with a companion star, this lone black hole has no nearby star, making it more difficult to detect but confirmable through the team’s observations.
- This discovery is the first confirmed lone black hole, and the team hopes the 2027 launch of the Nancy Grace Roman Space Telescope will help identify more of these elusive objects.
Astronomers have confirmed the existence of a lone black hole, an object previously unseen by scientists. This discovery, named OGLE-2011-BLG-0462, was made by a team of researchers at the Space Telescope Science Institute (STScI) in collaboration with experts from the University of St Andrews and the European Southern Observatory. The team published their findings in The Astrophysical Journal, explaining how they used new and older data to identify the object as a black hole conclusively.
The object, originally spotted in 2011, was observed using the Hubble Space Telescope over several years, from 2011 to 2017. In 2021 and 2022, further data from Hubble and the ESA’s Gaia space probe were analyzed. The object, located in the constellation Sagittarius, was found to be about seven times the mass of our sun. This mass ruled out the possibility of it being a neutron star, a similar type of cosmic object. The researchers also found that the object caused light from a distant star to magnify and shift as it passed in front of it, further confirming its identity as a black hole.
Previously, all known black holes had a companion star, making them easier to detect by observing how they affect their neighbor’s light. The discovery is unique because it is a lone black hole without any star nearby. This makes it much harder to detect, but the team’s observations allowed them to confirm its existence.
This discovery marks a significant milestone in astronomy, as it is the first confirmed case of a lone black hole. The researchers hope that the upcoming Nancy Grace Roman Space Telescope, set to launch in 2027, will help identify more of these elusive objects in the future.
References
- Yirka, B. & Phys.org. (2025, April 18). Astronomers confirm the existence of a lone black hole. Phys.Org; Phys.org. https://phys.org/news/2025-04-astronomers-lone-black-hole.html
- Sahu, K. C., Anderson, J., Casertano, S., Bond, H. E., Dominik, M., Calamida, A., Bellini, A., Brown, T. M., Ferguson, H. C., & Rejkuba, M. (2025). Ogle-2011-blg-0462: An isolated stellar-mass black hole confirmed using new hst astrometry and updated photometry. The Astrophysical Journal, 983(2), 104. https://doi.org/10.3847/1538-4357/adbe6e
