Wrap your head around this one: Astronomers using the Hubble Space Telescope are seeing the same star explosion over and over again, thanks to an optic trick.
The explosion, or supernova, happened 9 billion years ago on the other side of the universe. It’s too far away for even the Hubble to see without this trick of light. In this case, light rays from the star have been bent and magnified by the gravity of an intervening cluster of galaxies, so multiple images of the explosion have appeared.
This is the first time astronomers have been able to see the same explosion over and over again, and the images they’ve seen show different moments in the explosion. Astronomers will be able to use the delays between these appearances to refine their measurements of how fast the universe is expanding.
Read the story here, from the New York Times.
