Image from a simulation of a binary black hole merger seen in visible light near from the black holes
GW150914, the first ever detected gravitaional wave, came from two black holes that merged over a billion light years from Earth. This picture is extracted from a computer simulation showing what this would look like up close.
The black holes are near us, in front of a sky filled with stars and gas and dust. The black regions are the shadows of the two black holes: no light would reach us from these areas. Light from each star or bit of gas or dust travels to our eyes along paths (light rays) that are greatly bent by the holes’ gravity and by their warped spacetime.
Credit: SXS Lensing (License: CC-BY-SA 4.0)