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Using NASA's
Spitzer Space Telescope, scientists have found a bizarre
ring of material around the magnetic remains of a star
that blasted to smithereens, NASA reported Wednesday.
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.
"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
Center, 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.
Source:Xinhua |