Astronomers Discover Two Closest Black Holes to Earth

Astronomers have made an exciting discovery using data from the European Space Agency’s Gaia mission. They have found not one, but two black holes that are the closest to Earth ever discovered. The black holes, named Gaia BH1 and Gaia BH2, are located just 1560 and 3800 light-years away from us, respectively. They can be found in the direction of the constellations Ophiuchus and Centaurus.

The black holes were discovered by studying the movement of their companion stars. The stars exhibited a strange ‘wobble’ in their movement, indicating that they were orbiting a very massive object. In both cases, the objects were found to be approximately ten times more massive than our Sun. Other possible explanations for these massive companions, such as double-star systems, were ruled out because they did not seem to emit any light.

Until recently, all known black holes were discovered by the emission of light, usually at X-ray and radio wavelengths, produced by material falling into them. However, these new black holes are truly black and can only be detected by their gravitational effects. The distance of the stars to the black hole and the orbits of the stars around them are much longer than for other known binary systems of black holes and stars.

These closer star-black hole pairs, called X-ray binaries, tend to be very bright in X-ray and radio light and are thus easier to find. But these new discoveries suggest that black holes in wider binaries are more common. This means that there could be many more black holes out there waiting to be discovered.

Kareem El-Badry, the discoverer of the new black holes and researcher at the Harvard-Smithsonian Center for Astrophysics in the US and the Max-Planck Institute for Astronomy in Heidelberg, Germany explains that “What sets this new group of black holes apart from the ones we already knew about is their wide separation from their companion stars. These black holes likely have a completely different formation history than X-ray binaries.”

This discovery has important implications for our understanding of black holes and their formation. It suggests that there may be many more black holes out there that we have yet to discover because they do not emit any light.

These exciting discoveries were made possible by data from Gaia, which is mapping our galaxy in unprecedented detail. Gaia is providing astronomers with a wealth of data that is helping them make new discoveries about our galaxy and its inhabitants.