NASA's Fermi Spots 'Starquake' in a Magnetar Storm

NASA's Fermi detected a rapid-fire storm of high-energy blasts from a magnetar, a highly magnetized neutron star. The findings reveal a bit more about "starquakes" and the underlying signals related to seismic waves rippling through the magnetar.

"Fermi's Gamma-ray Burst Monitor (GBM) has captured the same evidence from smaller and much more frequent eruptions called bursts, opening up the potential for a wealth of new data to help us understand how neutron stars are put together," said Anna Watts, co-author of the new study, in a news release. "It turns out that Fermi's GBM is the perfect tool for this work.

Neutron stars are the densest, most magnetic and fastest-spinning objects in the universe that scientists can observe directly. Each of these magnetars is actually the crushed core of a massive star that ran out of fuel and exploded as a supernova. They possess magnetic fields that are trillions of times stronger than Earth's, and the eruptive activity observed from magnetars requires fields that are 1,000 times stronger still.

In this case, the scientists examined a burst storm from SGR J1550-5418, an object that was discovered by NASA's Einstein Observatory. Located about 15,000 light-years in the constellation Norma, it entered a period of eruptive activity that resulted in hundreds of bursts in as little as 20 minutes.

After examining the data, the researchers confirmed that the vibrations and frequency ranges are the same as had been previously witnessed in giant flares.

"We think these are likely twisting oscillations of the star where the curst and the core, bound by the super-strong magnetic field, are vibrating together," said Watts. "We also found, in a single burst, an oscillation at a frequency never been before and which we still do not understand."

The findings reveal a bit more about the interior workings of magnetars. This, in turn, tells scientists a bit more about the environment of space. Currently, the researchers are looking for more bursts to learn more about magnetars.