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.