Baby supernova seen right in our neighborhood

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - A baby supernova, just over a century old, has been found in the middle of our own Milky Way galaxy and provides an unprecedented opportunity to watch a star dying, astronomers said on Wednesday.

The supernova, known as G1.9+0.3, would have made a bright flash when it first exploded 140 years ago but was not seen because dust obscures it, David Green of Britain's University of Cambridge and colleagues reported.

"It's by far the youngest supernova identified in the galaxy," Green told reporters in a telephone briefing.

Green first identified the object in 1985 as a possible supernova, using radio readings from the U.S. National Science Foundation's Very Large Array.

In 2007, Stephen Reynolds of North Carolina State University and colleagues looked at it using the orbiting Chandra X-Ray Observatory. They were surprised to find it was 16 percent bigger than the radio measurements.

"The only reasonable explanation we could come up with was, in the 22 years between those observations, it had grown by that rate," Reynolds said.

They extrapolated its rate of growth to date the original explosion at 140 years ago.

The supernova is at the center of the galaxy, roughly 25,000 light-years from Earth. A light-year is the distance light travels in one year -- about 5.8 trillion miles.