Ghost black hole discovered through microlensing

Mysterious, ghost-like black hole may have been discovered by UC Berkeley researchers

Quote:

"This is the first free-floating black hole or neutron star discovered with gravitational microlensing," Lu told the outlet. Lu has been hunting for free-floating black holes since 2008, and has been observing OB110462 since 2020. "With microlensing, we're able to probe these lonely, compact objects and weigh them. I think we have opened a new window onto these dark objects, which can't be seen any other way." Though black holes are typically invisible, researchers can use gravitational microlensing to see how they warp and distort light from distant stars with their powerful gravitational field.

Isn't that crazy, if true? Something you can't even see except for how it lenses the light behind it. Sometimes you see black holes because they give off X-rays (from the accretion disk of course, not the black hole itself) or due to its effects on a nearby companion star. The first black hole ever discovered was called Cygnus X-1, which was found due to the X-rays that it gives off.

The article also mentions that our galaxy is estimated to contain about 200 million black holes. About 1 for every 1,000 stars.

via International Skeptics Forum https://ift.tt/ZORBNu6