The universe is a pretty incredible and gorgeous place, but it helps to be reminded. Case in point, an image astronomers released last week shows a phenomenon called an Einstein Cross, duplicating a hidden image of a distant and brilliant supernova four separate times.
The stunning image is thanks to an interesting quirk of gravity. The light is being bent around one galaxy in a massive cluster (MACS J1149.6+2223) five billion light-years away, like water flowing around a sphere. The four projected images were captured by the Hubble Telescope in a formation known as an Einstein Cross.
The powerful gravity of a galaxy embedded in a massive cluster of galaxies in this Hubble Space Telescope image is producing multiple images of a single distant supernova far behind it.
Einstein crosses come from so-called “gravitational lensing.” Predicted in his theory of general relativity, Albert Einstein described how massive objects in space could bend the fabric of space-time, warping, magnifying, and redirecting light traveling through the cosmos. If the geometry lines up just right, a viewer, in this case the Hubble Space Telescope, can see multiple images of the same object. Without gravitational lensing, this supernova that sits about nine billion light-years away would have been far too dim to be seen from Earth.
What is interesting about this image is that the light from the supernova doesn’t bend at the same rate. The light that makes up each projection from the supernova has taken a different path to reach the Earth, meaning the four views are showing the event during different stages of the cosmic calamity.
The lens will show the supernova exploding multiple times, but each “playback” will come at a different speed. Scientists expect the supernova will replay in a different part of the cluster sometime in the next decade, maybe even next year. When ever it comes, it will help astronomers gather information about the universe’s rate of expansion. And also give us some pretty unbelievable images at the same time.