Astronomers Just Found One Of The Biggest Black Holes Of All Time – SlashGear

Black holes can be tricky to detect because we can’t actually see them directly. Black holes are so dense that anything that comes too close to them, even light, is pulled in by their gravity and can’t escape if it passes a point called the event horizon. That means the black hole itself is dark — hence the name.

However, that doesn’t mean black holes are invisible. In fact, the region just around the black hole can glow brightly. That’s because gas and dust are drawn toward the black hole by gravity, and orbit around it before they pass the event horizon. As that dust and gas orbits, friction causes it to heat, which in turn makes it glow. This glowing shell of dust and gas is often visible even over great distances, which is how the first ever image of a black hole was captured.

To discover this new, enormous black hole though, the researchers relied on a particular phenomenon called gravitational lensing. This happens due to the tremendous gravity of massive, dense objects like black holes. The gravity they produce is so extreme that it actually warps space-time, causing light rays to bend.

The huge black hole was identified by looking at light from a distant galaxy which showed an arc, which is an indicator of gravitational lensing. The arc was first seen in 2004, but it wasn’t until 18 years later that a supercomputer helped to model how massive the supermassive black hole must have been to cause that kind of lensing.