![X-ray image of two black holes in the galaxy NGC 6240. Binary systems like this are possibly the origin of the most massive black holes in the cosmos. [Credit: NASA/CXC/MPE/S.Komossa et al. ]](https://bowlerhatscience.files.wordpress.com/2014/02/09_ngc-6240.jpg?w=474&h=407)
X-ray image of two black holes in the galaxy NGC 6240. Binary systems like this are possibly the origin of the most massive black holes in the cosmos. [Credit: NASA/CXC/MPE/S.Komossa et al.]
Earth emits gravitational waves as it orbits the Sun, though the amount of energy lost is imperceptible over the lifetime of the Solar System. Binary black holes are a different matter: Once they are relatively close, they shed a tremendous amount of energy, bringing them closer together with each orbit. (Binary black stars are thought to emit more gravitational energy as they merge than regular stars emit in the form of UV, IR, and visible light over their entire lifetimes of billions of years.) Eventually their event horizons will touch, and the system emits a lot more gravitational waves in a phase known as “ring-down,” as the lumpy, uneven merged mass becomes a smooth, perfectly symmetrical black hole. [Read more…]