In the past we’ve reported about how the Roman Space Telescope is going to potentially be able to detect hundreds of thousands of exoplanets using a technique known as “microlensing”. Exoplanets won’t be the only things it can find with this technique though – it should be able to find solitary black holes as well.
Solitary black holes are unique, as most black holes that scientists have “found” are those that are directly interacting with another object. However, those that are relatively small that could be roving around the galaxy by themselves which would be almost impossible to find since they absorb all electromagnetic wavelengths.
UT video describing microlensing
Usually these small black holes weigh around 10 times the weight of the sun. They form when a star dies and either goes supernova or collapses directly into a black hole, depending on its weight. If the black hole isn’t surrounded by any gas or dust to absorb, it would then become essentially invisible to almost all instruments.
So far scientists have found 20 of these “stellar mass” black holes, but only because they are next to a different astronomical object, making their gravitational force apparent in the way that ...