FLY-BY OF A SCHWARZSCHILD BLACK HOLE
What you’re seeing is a sequence of “Einstein Rings”
Einstein Ring is a term from observational astronomy. It’s an artifact of the gravitational lensing of light (from a star or galaxy) by a massively massive astronomical object (like a black hole or another galaxy).
In order for an Einstein Ring to appear, all three—the light source, the massive lens, and the observer—must all be aligned. In other words, it occurs when the object that you’re seeing as an Einstein ring is directly behind the object that is the gravitational lens.
Gravitational lensing is predicted by Albert Einstein’s theory of general relativity. Instead of light from a source traveling in a straight line (in three dimensions), it is bent by the presence of a massive body, which distorts spacetime.The animation above is a simulation depicting a zoom-in on a Schwarzschild black hole in front of the Milky Way.
The odd-numbered rings correspond to [images of objects] which are behind the black hole (from the observer’s point of view); they correspond here to the bright yellow region of the galactic disc (close to the galactic center).
- The first Einstein ring corresponds to the most distorted region of the picture and is clearly depicted by the galactic disc.
- The zoom then reveals a series of 4 extra rings, increasingly thinner and closer to the black hole shadow. They are easily seen through the multiple images of the galactic disk.
The even-numbered rings correspond to images of objects which are behind the observer. These objects appear bluer since the corresponding part of the galactic disc is thinner and hence dimmer. [WP]
SOURCE: Einstein ring - Wikipedia).
The animation was created by Wikipedia contributor Urbane Legend.