[LINK] "Crouching Tiger Hidden Magnetar"

[rfmcdonald]

Markus Hammonds' Discovery news post suggests that there may be many more magnetars in the galaxy that previously believed.

Magnetars are a rare type of neutron star, with powerful magnetic fields making them prone to occasional violent outbursts. Only a small handful of these curious beasts have been found in our galaxy, but new research from the Chandra X-ray Observatory implies that they may be a lot more common than previously expected. They may simply be in hiding.

Magnetars are traditionally thought to show intense magnetic fields on their surfaces, reaching thousands of times the strength of the fields found on regular neutron stars. But 6,500 light years from Earth, one magnetar in particular, SGR 0418+5729, seems to buck the trend. On the surface, it appears to be just an ordinary neutron star.

It seems, there may be a lot which we don’t know about these massive stellar magnets. Nanda Rea at the Barcelona Institute of Space Science explained that ”we have found that SGR 0418 has a much lower surface magnetic field than any other magnetar,” elaborating that there may be some important consequences for our understanding of both neutron stars and the supernova explosions which create them.

For over three years, researchers kept a watchful eye on SGR 0418, using some of the world’s best x-ray observatories. By measuring changes in its rotation during x-ray outbursts, they managed to accurately estimate the external magnetic field strength of the neutron star.

Strangely, at least on the outside, that magnetic field appeared a lot weaker than they were expecting. And it’s very likely that there are other neutron stars out there which are hiding their true colors. “We think that about once a year in every galaxy a quiet neutron star should turn on with magnetar-like outbursts, according to our model for SGR 0418,” commented José Pons of the University of Alicante, Spain, who hopes that many more such objects may come to light with further research.