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Astronomers discover giant elliptical ring
around dead starFrom
ANI
Washington, May 29: Astronomers
have detected a giant elliptical ring around a
rare star known as magnetar, a highly magnetized
neutron star and the remnant of a brilliant
supernova explosion signaling the death throes of
a massive star.
Magnetars
are formed when a giant star ends its life in a
supernova explosion, leaving behind a super dense
neutron star with an incredibly strong magnetic
field.
Stefanie Wachter, research scientist
at NASA's Spitzer Science Center at the California
Institute of Technology, led the study, which
links the origin of the magnetar to a nearby
cluster of massive stars, whose light is dominated
by two red supergiants at the
center.
"Discovering the ring is
groundbreaking because it discovers some other
phenomenon associated with, and physically near, a
magnetar," said Donald Figer, professor at
Rochester Institute of Technology's Chester F.
Carlson Center for Imaging Science.
According to Figer, "Magnetars possess
magnetic fields a million billion times stronger
than the magnetic field of the Earth."
The
magnetic field of a magnetar is one petagauss,
while, in comparison, Earth's magnetic field
strength registers at 0.5 gauss, the Sun at one
gauss and a sunspot at about 1,000 gauss.
These extreme fields stretch the very
fabric of matter, contorting atoms into thin
cigar-shaped structures.
The stellar
eruption may result from stress induced by the
magnetic field dragging on the rapidly spinning
star.
A fissure in the surface of the
magnetar creates a "starquake," akin to
earthquakes. The biggest variety of these
eruptions can temporarily produce over a thousand
times more energy than all of the stars in a
galaxy.
The ring seen by Spitzer could not
have formed during the original explosion, as any
material as close to the star as the ring would
have been disrupted by the supernova shock wave.
Scientists suspect that the ring my
actually be the edges of a bubble that was
hollowed out by an explosive burst from the
magnetar in 1998.
"We think that the ring
was created when a giant flare from the SGR (soft
gamma repeater) carved a cavity into the dusty
environment surrounding the magnetar, thus
naturally explaining why the ring is centered on
the magnetar," said Wachter.
Copyright
Asian News International
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