Scientists find strange ring circling dead star

May 29th, 2008 - 12:49 pm ICT by admin  

Washington, May 29 (Xinhua) Scientists have found a bizarre ring of material around the magnetic remains of a star that blasted to smithereens, the National Aeronautics and Space Administration (NASA) has said. The stellar corpse, called SGR 1900+14, belongs to a class of objects known as magnetars.

These are the cores of massive stars that blew up in supernova explosions, but unlike other dead stars, they slowly pulsate with X-rays and have tremendously strong magnetic fields.

NASA’s Spitzer Space Telescope had spotted the ring.

“I was flipping through archived Spitzer data of the object, and that’s when I noticed it was surrounded by a ring we’d never seen before,” said Stefanie Wachter of NASA’s Spitzer Science Centre, who found the ring serendipitously.

Wachter is lead author of a paper about the findings in this week’s Nature. Wachter and her colleagues think that the ring, which is unlike anything ever seen before, formed in 1998, when the magnetar erupted in a giant flare.

They believe the crusty surface of the magnetar cracked, sending out a flare, or blast of energy, that excavated a nearby cloud of dust, leaving an outer, dusty ring.

This ring is oblong, with dimensions of about seven by three light-years. It appears to be flat, or two-dimensional, but the scientists said they can’t rule out the possibility of a three-dimensional shell.

The discovery could help scientists figure out if a star’s mass influences whether it becomes a magnetar when it dies. Though scientists know that stars above a certain mass will “go supernova”, they do not know if mass plays a role in determining whether the star becomes a magnetar or a run-of-the-mill dead star.

According to the science team, the ring demonstrates that SGR 1900+14 belongs to a nearby cluster of young, massive stars.

By studying the masses of these nearby stars, the scientists might learn the approximate mass of the original star that exploded and became SGR 1900+14.

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