New kind of space blast seen not far from Earth

WASHINGTON, Feb 24 (Reuters) A new kind of cosmic explosion has been spotted in Earth's celestial neighborhood, and amateur astronomers in the Northern Hemisphere might be able to see it next week, scientists yesterday reported.

The blast seemed a lot like a gamma-ray burst, the most distant and powerful type of explosion known to astronomers.

But when scientists first detected it with NASA's Swift satellite on Feb. 18, the explosion was about 25 times closer and lasted 100 times longer than a typical gamma-ray burst.

''This is totally new, totally unexpected,'' said Neil Gehrels, Swift's principal investigator. ''This is the type of unscripted event in our nearby universe that we hoped Swift could catch.'' The explosion originated in a star-forming galaxy about 440 million light-years away towards the constellation Aries (The Ram). A light-year is about 6 trillion miles (10 trillion km), the distance light travels in a year.

This would be the second-closest gamma-ray burst ever detected, if indeed it is one.

The burst lasted for nearly 2,000 seconds, or about 33 minutes, astronomers said in a statement. Most bursts last a few milliseconds to tens of seconds. It also was surprisingly dim.

Scientists at Italy's National Institute for Astrophysics found hints of a budding supernova an exploding star when they saw the afterglow from the original explosion grow brighter in optical light.

If it is a supernova, scientists will have an unprecedented view of one from start to finish.

Scientists will attempt observations with the Hubble Space Telescope and Chandra X-ray Observatory. Amateur astronomers in dark skies might be able to see the explosion with a 16-inch (40-cm) telescope.

REUTERS SB SP1048