Scientists have spotted an exploding star — and it may be the same one that first popped up 50 years ago.
Astronomers using the Hubble Space Telescope have found what appears to be the same star blowing itself up in the same supernova explosion, which is repeating at least in our eyes due to Einstein’s theory of gravitational lensing, according to a New York Times report.
The star exploded 9 billion years ago on the other side of the universe from us, which would be beyond even Hubble’s range if it weren’t for some help from a cluster of galaxies.
The galaxies magnify and bend light from the supernova, allowing us to see it and creating multiple images of the same phenomenon.
Scientists have spotted three of them in a tight formation that has been called the Einstein Cross, wrapped around one of the galaxies within the cluster, and a fourth image is likely to be on its way. The galaxy has caused the light rays to follow different paths, meaning that each image captures a different moment in the supernova’s history. The first one showed up in 1964, the second one in 1995, the third in 2014, and the fourth is likely to pop up in the next 10 years.
It’s the first time astronomers have found something like this, where they can view the same explosion over and over again, and it helps them understand things like dark matter and the expansion of the universe.
Patrick Kelly, who works at the University of California, Berkeley, and discovered the supernova images back in November, said he was “astounded” by the find. He is the lead author of the study discussing the supernova, which was published in the journal Science.
Although scientists have witnessed gravitational lensing before, and certainly supernovas, a combination of the two creating a multiple image is a very different experience.
Supernovas are fairly uncommon experiences, with just one happening each century in a standard galaxy. They create spectacular light shows and blast space dust into the cosmos, which can create new worlds. They then collapse into neutron stars or black holes.
The supernova is expected to show up again in the next 10 years, according to Kelly. By timing the delays between each image, astronomers will be able to adjust their models of how fast the universe is expanding and to map out dark matter, the mysterious substance that makes up most of the known matter in the universe.