In this mesmerizing image captured by the Hubble telescope, it almost seems like there are six celestial bodies at its center. In fact, there are only three: a pair of galaxies and a quasar.
"Hubble data also indicates that there is a seventh spot of light in the very center, which is a rare fifth image of the distant quasar. This rare phenomenon is caused by the presence of two galaxies in the foreground that act as a lens," writes ESA on its website.
So what exactly is happening here?
What's going on here can be attributed to a phenomenon called gravitational lensing that was previously predicted by Einstein.
The end result is an Einstein ring where a quasar behind has its light magnified as it passes through the gravitational field of the two galaxies in the foreground. The mass of the two foreground galaxies is so high that any light that travels close to the pair enters our telescopes distorted and magnified.
In the end, we have a “seeing quintuple” effect due to gravitational lensing. Gravitational lensing causes the fabric of space to warp such that the light traveling through that space from a distant object is bent and magnified enough so that humans all the way here on Earth can observe multiple magnified images of the distant celestial object.
So basically, we are seeing a kind of illusion. The quasar in this image actually lies further away from Earth than the pair of galaxies in between, but its light has been bent to give off a magnified appearance because of their enormous mass. This gives the illusion that the galaxy pair is surrounded by four quasars. However, in reality, a single lonely quasar lies far beyond them and out of their reach.
Space never ceases to amaze us and this is not the first time Hubble captures gravitational lensing. Just last month the technique was used to capture an image of a distant galaxy. Last but not least, the technique can also be used to spot black holes.