A study recently published in the journal Science details how a team of astronomers using NASA's Hubble Space Telescope were able to see an exploding star that is not only incredibly far away, but they were able to see it from four different perspective - all by looking at one spot in the sky.
How is this possible? The galaxy is actually full of what can be best described as magnifying lenses - light bent by the massive gravitational forces of nearby galaxy clusters in such a way that it reaches far farther than it normally would. Such a natural lens recently allowed astronomers to observe an ancient galaxy near the very center of the universe - learning new secrets about how the first stars came to be.
This latest lens is now showing something just as revealing: perspectives of a star as it goes supernova from four different angles thanks to the unique manner in which it is bending, magnifying, and replicating the event's light.
"With four perspectives, you can actually measure the difference in the light paths," study co-author Kasper Schmidt, a physicist at The University of California, Santa Barbara, said in a statement. "You can think of these time-variable source images of the supernova as trains. Each leaves the station at the same time but arrives at different times because the 'routes' and the 'landscape' they travel through are not the same."
After ensuring that each image was indeed a copy of one event, rather than a quadruple-simultaneous-supernova (a likely impossible event), the researcher were even able to measure that each image had arrived into Hubble's field of view at different times, suggesting the variously magnified light had traveled different distances to get there.
"That lets us compare the size of the universe 5 billion years ago to the size of the universe today, so we can measure how fast the universe is expanding," co-author Curtis McCully excitedly added.
However, it will take some time to work out this exceptionally complex data.
The researchers have since concluded that the supernova they are seeing is a stunning 9.3 billion light years away - right at the edge of the observable Universe. Without this unusual and luck lensing, the light from the event may not have even been detected, but now they suspect that they will even have a chance to see the star explosion unfold again in about a decade's time.