Supernova researchers win Nobel Prize in Physics

STOCKHOLM, Sweden, Oct. 4 (UPI) -- The 2011 Nobel Prize in Physics was awarded in Stockholm to three astrophysicists who discovered the expansion of the universe is accelerating, officials said.

The Royal Swedish Academy of Sciences said Saul Perlmutter, Brian P. Schmidt and Adam G. Riess were awarded the Nobel Prize in Physics "for the discovery of the accelerating expansion of the Universe through observations of distant supernovas."

Half the award goes to Perlmutter, head of the Supernova Cosmology Project at Lawrence Berkeley National Laboratory and a professor at the University of California, Berkeley, Calif. The other half of the $1.4 million prize will be split between Schmidt and Riess of the High-z Supernova Search Team.

Schmidt, who led the High-z team, is affiliated with the Australian National University, Weston Creek, while Riess is a professor at Johns Hopkins University and Space Telescope Science Institute, Baltimore, Md.

Two teams, one led by Perlmutter and the other by Schmidt, raced to map the universe by locating the most distant supernova, or exploding star. The teams focused a particular kind of supernova, called type Ia supernova, which is an an explosion of an old compact star that is as heavy as the sun but as small as the Earth, the Royal Swedish Academy of Sciences said Tuesday.

The researchers said they found over 50 distant supernovas whose light was weaker than expected, which is a sign the expansion of the universe is accelerating.