New technique uncovers supernovae

space#topic

A new imaging technique has allowed scientists to discover two dying stars at the edge of the universe - further away than any ever detected.

When a huge star more than 50 times the mass of the sun dies it explodes, causing a supernova. Some 11 billion years ago, light from the exploding stars began its journey to Earth. This was shortly after the "Big Bang" that created the cosmos.

Up until now, scientists looking for supernovae compared pictures of the same patch of sky taken at different times, looking for changes, with a new light indicating an explosion.

However using the new technique, pictures taken over a year are blended together and compared with image compilations from previous 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."

"The universe is about 13.7 billion years old, so really we are seeing some of the first stars ever formed."

The research is reported in the journal Nature.

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