A supernova occurs when a massive star more than 50 times the mass of the Sun dies in a powerful bright explosion
Two dying stars at the edge of the universe and further away than any detected to date have been discovered using a new imaging technique.
Light from the exploding stars, or supernovae, began its journey to Earth 11 billion years ago, not long after the “Big Bang” that created the cosmos.
The next furthest large supernova known is six billion light years away.
A supernova occurs when a massive star more than 50 times the mass of the Sun dies in a powerful bright explosion.
Normally scientists find supernovae by comparing pictures taken at different times of the same patch of sky and looking for changes. A new light could indicate one of the explosions.
The new technique involves blending together pictures taken over the course of a year, and comparing them with image compilations from other years.
Dr Jeff Cooke, from the University of California at Irvine, said: “If you stack all of those images into one big pile, then you can reach deeper and see fainter objects. It’s like in photography when you open the shutter for a long time. You’ll collect more light with a longer exposure.”
Dr Cook found four supernovae, including the two distant objects, after analysing images from the Canada-France-Hawaii Telescope in Hawaii.
He said: “The universe is about 13.7 billion years old, so really we are seeing some of the first stars ever formed.”
Dr Cook and other scientists last year discovered an early-stage cluster of galaxies 11.4 billion light years away, the most distant ever detected.
The new research is reported in the journal Nature.