Oldest Supernova to Date Discovered

July 9, 2009 -- After combing through years of archival images of distant galaxies, astronomers have found the exploded remains of a star that is about 11 billion light years from Earth, the most distant supernova found to date.

The discovery, reported in this week's Nature, promises to open the early universe to greater scrutiny in an ongoing effort to understand how galaxies form and evolve.

The type of supernovae found by University of California-Irvine astronomer Jeff Cooke and colleagues can serve as a beacon, because the supernovae not only explode with a brilliant flash of light, but also illuminate shells of gas that they have been shedding for years before their violent deaths.

When a star explodes, ejected material rams into surrounding gas shells, causing them to glow. Unlike the explosion, which is relatively short-lived, the glowing gas shells radiate for years.

That gave Cooke and colleagues an opportunity to verify their findings, which were drawn from analysis of imagery from the Canada-France-Hawaii Telescope Legacy Survey. The team selected about 60,000 target galaxies and combined the light collected during six months of near-daily observations. They then compared that result with data compiled from a six-month period of another year.

WATCH VIDEO: Discovery News finds out why a star's age matters.

Related Content:

• Supernova May Revise Star Evolution Theory
• Congrats, Milky Way: It's a Baby Supernova
• HowStuffWorks.com: Stars
• More Discovery News

Four targets showed brightening over time, perhaps due to supernovae explosions. Cooke then used the Keck Telescope to look for the glowing shell remains for verification.

"In retrospect, I can't believe we haven't capitalized on this method sooner," said astronomer Alicia Soderberg, with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

Cooke plans to continue combing archived images -- he's only about one-fifth of the way through the archival images -- to look for additional distant supernovae. Eventually, with more powerful telescopes, he hopes to obtain the chemical fingerprints of the exploded remains to determine if stars forming in very young galaxies were made of different materials than stars born in later-generation galaxies.

Astronomers believe that heavier elements were made in stars and then distributed in space to become raw materials for future galaxies.

"We should be able to do this when the supernovae is much brighter and measure metal content," said Ray Carlberg with the University of Toronto.

Related Links:

Astronomers ID Supernova First Seen 400 Years Ago

Blog: Space Disco

Ancient Supernova Sparked Humanity?