Astronomers spot a 'bizarre' strobe light star

A "most bizarre" strobe light star reported by European astronomers likely belongs to a long-sought family of compact "neutron" stars.

It initially showed up as a gamma-ray burst, leading astronomers to think it was the death of a star in the far-off universe. But after that first gamma-ray pulse, there was a three-day period of activity during which this odd celestial object emitted 40 visible-light flashes before disappearing again. Eleven days later, there was a brief near-infrared flaring episode recorded by ESO's Very Large Telescope. Then the weird object went visibly "silent" again.

"We are dealing with an object that has been hibernating for decades before entering a brief period of activity," said Alberto J. Castro-Tirado, lead author of a paper in this week's issue of Nature.

Astronomers now think this celestial enigma is a 'magnetar' located in our own Milky Way galaxy, about 15,000 light-years away in the area around the constellation of Vulpecula, the Fox. Magnetars are a type of young neutron stars. They boast a magnetic field that's a billion billion times stronger than Earth's.

To put that in perspective for those of us with the financial crisis willies: “A magnetar would wipe the information from all credit cards on Earth from a distance halfway to the Moon,” explains Antonio de Ugarte Postigo, the study's co-author.

Because magnetars can be celestially silent for decades at a time, they're hard to pin unless we're looking at the right place at the right time. Postigo says there's likely a large population of them in the Milky Way even though we've only identified about 12.

The magnetar, known as SWIFT J195509+261406, is a candidate for what scientists have been looking for: A magnetar moving towards a pleasant retirement as its magnetic fields decay.

Photo: The twisting of magnetic field lines in magnetars give rise to 'starquakes', which will eventually lead to an intense soft gamma-ray burst. In the case of the SWIFT source, the optical flares that reached the Earth were probably due to ions ripped out from the surface of the magnetar and gyrating around the field lines.
Found at: http://blogs.usatoday.com/sciencefair/2008/09/astronomers-spo.html