Thursday, October 02, 2008

Swift discovers a Magnetar?!

Shaun loves to find the strange when it comes to astronomy. As we have seen with some of his earlier stories on BMU (*Last Light, Hubble, Curtain Call) and this discovery is no exception.

On June 10, 2007, a spike of gamma-rays lasting less than five seconds was detected by NASA's Swift satellite. But this high-energy flash wasn't a gamma-ray burst - which would herald the formation of a black hole. During the next three days, the object brightened and faded in visible light 40 times! Eleven days later, it flashed again, this time at infrared wavelengths. Then, it disappeared from view.

Astronomers think the object was a neutron star -- the crushed core of a massive star that long ago exploded as a supernova. A team of 42 scientists have concludes that the object is a special type of neutron star called a magnetar, of which only a dozen have been discovered so far.

Although measuring only about 12 miles across -- neutron stars have the strongest magnetic fields in the cosmos. magnetars may have magnetic fields more than 100 times the strength of typical neutron stars.

So what caused this particular magnetar to put on such a dazzling show? Neutron stars have massive gravities as well as incredible fast rotation. Mix that with the ultra strong magnetic field and you have the makings of what is called a star quake. These quakes are so strong that they fracture the surface of the magnetar and eject huge amounts of energy which is spun up by the magnetic fields.

> NASA's Swift Web site

*these stories and many others by Shaun Saunders can be found in his book Navigating the New World are available from Anti Sf

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