Astronomers have captured the moment a far off star exploded, not once but four times and in doing so they confirmed an effect predicted by Albert Einstein's general theory of relativity 100 years ago.
The exploding star, or supernova, was directly behind a cluster of huge galaxies whose enormous mass warped space-time, creating a cosmic magnifying glass.
Light from the supernova passing through the distorted region produced multiple images.
Astronomers using the NASA/ESA Hubble Space Telescope have, for the first time, spotted four images of a distant exploding star. The images are arranged in a cross-shaped pattern by the powerful gravity of a foreground galaxy embedded in a massive cluster of galaxies.
The theory explains how massive objects bend space-time to create what we feel as the force of gravity.
It can be envisaged by imagining a football pressing down the centre of a rubber sheet. A pea rolled into the depression would spiral inwards towards the ball.
Astronomers have looked for the kind of "gravitational lensing" event described in Science for the past 20 years.
The findings not only acts as a test of general relativity, but also provides information about the strength of gravity and the amount of dark matter and dark energy in the universe.
The study is published in the Science.
