SSS 2008-12-04（在线收听）

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.

It’s not every day we get a chance to time travel. Other than into the future at the rate of one second per second. But astronomers say they’ve done a little traveling into the past. In November of 1572, legendary astronomer Tycho Brahe peered up at the night sky. He saw what looked like a strangely bright star in the constellation Cassiopeia. It was brighter even than the nearby planet Venus. He studied that bright new star for five months, until it faded away. But what Brahe saw wasn’t a new star. It was actually an old star undergoing the brilliantly bright death of a supernova.

Scientists at the Subaru Telescope in Japan recently analyzed what could be called echoes of this more than 400-year-old event. They published their research in the December 4th issue of the journal Nature. Light from the original supernova bounced off dust particles in the interstellar clouds and eventually reached us here on earth more than four centuries later. Scientists used these echoes to determine that Brahe witnessed a type Ia supernova.

Thanks for the minute for Scientific American's 60-Second Science. I'm Cynthia Graber.