It is ‘only’ 1,926 light-years away and 33 times larger than our sun.
The Milky Way is home to smaller stellar black holes that arise from the collapse of massive stars in addition to the supermassive black hole at the center of our galaxy. Though most of them are still undiscovered, scientists estimate that our galaxy alone contains 100 million stellar black holes. The largest of the ones that have already been discovered is 21 solar masses in size, with an average size of about ten times that of our sun.
However, scientists have discovered the largest stellar black hole yet observed in our galaxy, measuring 33 times the mass of our sun, thanks to data gathered by the European Space Agency’s Gaia mission. About 1,926 light-years separate it from our planet, making it comparatively close as well.
Now known as Gaia BH3, it was first identified by a group of ESA scientists who were scouring mission data for anything out of the ordinary. They noticed the wobbling of an old giant star from the nearby constellation Aquila, which led them to the conclusion that it was orbiting a massive black hole.
Even though BH3 is currently the second closest known black hole to Earth, it was difficult to locate because there are not any nearby celestial bodies that could provide it with matter and cause it to glow in X-ray telescopes. We had only previously discovered black holes of a similar size in far-off galaxies.
The size of the recently discovered celestial body was verified by the ESA team using information from ground-based telescopes such as the European Southern Observatory. For their peers to begin studying, they also released an initial paper with their findings before releasing a more comprehensive one in 2025.
Gaia BH3. As of right now, all that is known about the star orbiting it is that it contains very few elements heavier than hydrogen and helium, and since stellar pairs typically have similar compositions, it is possible that the star that collapsed to form BH3 was the same one.
For a very long time, scientists have thought that because metal-poor stars lose less mass during their lifetimes, they are the ones that can eventually collapse into high-mass black holes. Stated differently, by the time of their demise, there would presumably still be plenty of material available for the formation of a massive black hole. This was the first indication that massive stellar black holes and metal-poor stars were related, and it also demonstrated that the formation of older giant stars differed from that of the younger stars in our galaxy.
Conclusion:
Future research on stellar black holes and binary systems will probably make use of information from BH3 and its companion star. As we work to solve the mysteries of the universe, the ESA thinks that BH3’s discovery is only the beginning and will be the subject of additional research.
